Registration form
Chlorination 303 CEU Training Course $200.00
48 HOUR RUSH ORDER PROCESSING FEE ADDITIONAL $50.00
Start and Finish Dates: ___________________________ You will have 90 days from this date in
order to complete this course
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1
Chlorination 303 11/7/2015 Assignment
DISCLAIMER NOTICE
I understand that it is my responsibility to ensure that this CEU course is either approved
or accepted in my State for CEU credit. I understand State laws and rules change on a
frequent basis and I believe this course is currently accepted in my State for CEU or
contact hour credit, if it is not, I will not hold Technical Learning College responsible. I
also understand that this type of study program deals with dangerous conditions and that
I will not hold Technical Learning College, Technical Learning Consultants, Inc. (TLC)
liable for any errors or omissions or advice contained in this CEU education training
course or for any violation or injury caused by this CEU education training course
material. I will call or contact TLC if I need help or assistance and double-check to
ensure my registration page and assignment has been received and graded.
State Approval Listing Link, check to see if your State accepts or has pre-approved
this course. Not all States are listed. Not all courses are listed. If the course is not
accepted for CEU credit, we will give you the course free if you ask your State to accept
it for credit.
Professional Engineers; Most states will accept our courses for credit but we do not
officially list the States or Agencies. Please check your State for approval.
State Approval Listing URL…
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You can obtain a printed version of the course from TLC for an additional $69.95 plus
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AFFIDAVIT OF EXAM COMPLETION
I affirm that I personally completed the entire text of the course. I also affirm that I
completed the exam without assistance from any outside source. I understand that it is
my responsibility to file or maintain my certificate of completion as required by the state
or by the designation organization.
Grading Information
In order to maintain the integrity of our courses we do not distribute test scores,
percentages or questions missed. Our exams are based upon pass/fail criteria with the
benchmark for successful completion set at 70%. Once you pass the exam, your record
will reflect a successful completion and a certificate will be issued to you.
2
Chlorination 303 11/7/2015 Assignment
Chlorination 303 CEU Course Answer Key
Name ___________________________
Telephone # ________________
Did you check with your State agency to ensure this course is accepted for credit?
Method of Course acceptance confirmation. Please fill this section
Website __ Telephone Call___ Email____ Spoke to_________________________
Did you receive the approval number if Applicable? _____________
What is the approval number if Applicable? ____________________
Please circle, underline, bold or X only one correct answer
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Chlorination 303 11/7/2015 Assignment
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Chlorination 303 11/7/2015 Assignment
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Chlorination 303 11/7/2015 Assignment
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Chlorination 303 11/7/2015 Assignment
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Chlorination 303 11/7/2015 Assignment
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Please fax the answer key to TLC
(928) 272-0747
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8
Chlorination 303 11/7/2015 Assignment
Please e-mail or fax this survey along with your final exam
CHLORINATION 303 CEU TRAINING COURSE
CUSTOMER SERVICE RESPONSE CARD
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9
Chlorination 303 8/9/2015 Assignment
10
Chlorination 303 8/9/2015 Assignment
Chlorination 303 CEU Course Assignment
The Chlorination 303 CEU Assignment is available in Word on the Internet for your
Convenience, please visit www.ABCTLC.com and download the assignment and e mail it
back to TLC.
You will have 90 days from the start of this course to complete in order to receive your
Professional Development Hours (PDHs) or Continuing Education Unit (CEU). A score of 70 %
is necessary to pass this course. If you should need any assistance, please email all concerns
and the completed manual to info@tlch2o.com.
I would prefer that you utilize the enclosed answer sheet in the front, but if you are
unable to do so, type out your own answer key. Please include your name and address
on your manual and make copy for yourself.
Multiple Choice, please select only one answer per question. There are no intentional
trick questions.
Principles of Modern Chemistry
1.
The current model of atomic structure is the quantum mechanical model.
_____________starts with the study of elementary particles, atoms, molecules, substances,
metals, crystals and other aggregates of matter. This matter can be studied in solid, liquid, or
gas states, in isolation or in combination.
A. Nuclear chemistry
D. Analytical chemistry
B. Neurochemistry
E. Traditional chemistry
C. Organic chemistry
F. None of the Above
2. The interactions, reactions and transformations that are studied in chemistry are usually the
result of interactions between atoms, leading to rearrangements of the ________which hold
atoms together. Such behaviors are studied in a chemistry laboratory.
A. Chemical bonds
D. Chemical compound
B. Chemical substance(s) E. Physical chemistry
C. Chemical(s)
F. None of the Above
3. _____________is a transformation of some substances into one or more different
substances. The basis of such a chemical transformation is the rearrangement of electrons in
the chemical bonds between atoms. It can be symbolically depicted through a chemical
equation, which usually involves atoms as subjects.
A. Chemical element(s)
D. A chemical reaction
B. An electron
E. Energy and entropy
C. Atom
F. None of the Above
4. The number of atoms on the left and the right in the equation for a _____________is equal.
(When the number of atoms on either side is unequal, the transformation is referred to as a
nuclear reaction or radioactive decay.)
A. Chemical transformation
D. The type of chemical reaction(s)
B. Atom
E. Mixture of substances
C. Chemical propertie(s)
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
5. _______________ a substance may undergo and the energy changes that may accompany
it are constrained by certain basic rules, known as chemical laws.
A. Chemical substance(s)
D. The type of chemical reaction(s)
B. Atom
E. Mixture of substances
C. Chemical propertie(s)
F. None of the Above
6.
A.
B.
C.
Energy and entropy considerations are invariably important in_________.
Chemical element(s)
D. Mixture of substances
An electron
E. Almost all chemical studies
The type of chemical reaction(s)
F. None of the Above
7. ______________ are classified in terms of their structure, phase, as well as their chemical
compositions. They can be analyzed using the tools of chemical analysis, e.g. spectroscopy and
chromatography. Scientists engaged in chemical research are known as chemists. Most
chemists specialize in one or more sub-disciplines.
A. Chemical substance(s)
D. The type of chemical reaction(s)
B. Atom(s)
E. Mixture of substances
C. Chemical propertie(s)
F. None of the Above
Matter
8. In chemistry, matter is defined as anything that has rest mass and volume (it takes up space)
and is made up of particles. The particles that make up matter have rest mass as well - not all
particles have rest mass, such as____________.
A. Chemical element(s)
D. The photon
B. An electron
E. Energy and entropy
C. Atom
F. None of the Above
9.
A.
B.
C.
Matter can be a pure chemical substance or_________________.
Chemical bond(s)
D. Forms of energy
Chemical substance(s) E. A mixture of substances
Chemical(s)
F. None of the Above
Atom
10. The atom is the basic unit of chemistry. It consists of a dense core called the atomic
nucleus surrounded by a space called the_____________.
A. Chemical element(s)
D. Photon
B. An electron
E. Electron cloud
C. Atom
F. None of the Above
11. The nucleus is made up of positively charged protons and uncharged neutrons (together
called nucleons), while the electron cloud consists of negatively-charged electrons which orbit
the nucleus. In a neutral atom, the negatively-charged electrons balance out the positive charge
of the ______________.
A. Nucleus
D. Negatively-charged electrons
B. Protons
E. Positively charged protons
C. Atom
F. None of the Above
(S) Means the answer can be plural or singular in nature
12
Chlorination 303 8/9/2015 Assignment
12. The nucleus is dense; the mass of a nucleon is 1,836 times that of an electron, yet the
radius of ___________is about 10,000 times that of its nucleus.
A. Nucleus
D. Negatively-charged electrons
B. An electron
E. Positively charged protons
C. An atom
F. None of the Above
13. ________________is also the smallest entity that can be envisaged to retain the chemical
properties of the element, such as electronegativity, ionization potential, preferred oxidation
state(s), coordination number, and preferred types of bonds to form (e.g., metallic, ionic,
covalent).
A. Nucleus
D. Negatively-charged electrons
B. An electron
E. Positively charged protons
C. The atom
F. None of the Above
Element
14. The standard presentation of the ______________ is in the periodic table, which orders
elements by atomic number. The periodic table is arranged in groups, or columns, and periods,
or rows. The periodic table is useful in identifying periodic trends.
A. Chemical element(s)
D. Photon
B. An electron
E. Energy and entropy
C. Atom
F. None of the Above
Compound
15. A compound is a pure chemical substance composed of more than one element. The
properties of a compound bear little similarity to those of its_______________.
A. Chemical bond(s)
D. Forms of energy
B. Elements
E. Physical chemistry
C. Chemical(s)
F. None of the Above
Chemical Compounds
16. A pure chemical compound is a chemical substance that is composed of a particular set of
molecules or ions. Two or more elements combined into one substance through a chemical
reaction form a chemical compound. All ______________are substances, but not all
substances are compounds.
A. Bulk chemical(s)
D. Compound(s)
B. Chemical(s)
E. A pure chemical compound
C. Mechanical processe(s) F. None of the Above
17. A chemical compound can be either atoms bonded together in molecules or crystals in
which atoms, molecules or ions form a crystalline lattice. ____________ based primarily on
carbon and hydrogen atoms are called organic compounds, and all others are called inorganic
compounds.
A. Bulk chemical(s)
D. Compound(s)
B. Chemical(s)
E. A pure chemical compound
C. Mechanical processe(s) F. None of the Above
18. Compounds containing bonds between carbon and a metal are called ____________.
A. Organometallic compound(s)
D. Mixture(s)
B. Chemical substance(s)
E. Chemical substance(s)
C. Isomer(s)
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
19. Compounds in which components share __________ are known as covalent compounds.
Compounds consisting of oppositely charged ions are known as ionic compounds, or salts.
A. Nucleus
D. Negatively-charged electrons
B. Electrons
E. Positively charged protons
C. The atom
F. None of the Above
20. In organic chemistry, there can be more than one chemical compound with the same
composition and molecular weight. Generally, these are called _______________.
A. Organometallic compound(s)
D. Mixture(s)
B. Chemical substance(s)
E. Chemical substance(s)
C. Isomer(s)
F. None of the Above
21. _________________usually have substantially different chemical properties, may be
isolated and do not spontaneously convert to each other. A common example is glucose vs.
fructose.
A. Isomers
D. Compound(s)
B. Chemical(s)
E. A pure chemical compound
C. Mechanical processe(s)
F. None of the Above
Substances versus Mixtures
22. All matter consists of various elements and________________, but these are often
intimately mixed together.
A. Chemical compounds
D. Mixture(s)
B. Chemical substance(s)
E. Chemical mixtures
C. Isomer(s)
F. None of the Above
23. _________________ contain more than one chemical substance, and they do not have a
fixed composition. In principle, they can be separated into the component substances by purely
mechanical processes. Butter, soil and wood are common examples of mixtures.
A. Bulk chemical(s)
D. Compound(s)
B. Chemical(s)
E. A pure chemical compound
C. Mechanical processe(s)
F. None of the Above
Chemicals versus Chemical Substances
24. While the term _______________ is a precise technical term that is synonymous with
"chemical" for professional chemists, the meaning of the word chemical varies for non-chemists
within the English speaking world or those using English.
A. Organometallic compound(s)
D. Mixture(s)
B. Chemical mixtures
E. Chemical substance(s)
C. Isomer(s)
F. None of the Above
25. For industries, government and society in general in some countries, the word chemical
includes a wider class of substances that contain many mixtures of such chemical substances,
often finding application in many vocations. In countries that require a list of ingredients in
products, the "chemicals" listed would be equated with "_________________".
A. Chemical bond(s)
D. Forms of energy
B. Chemical substance(s) E. Physical chemistry
C. Chemical(s)
F. None of the Above
(S) Means the answer can be plural or singular in nature
14
Chlorination 303 8/9/2015 Assignment
26. Within the chemical industry, manufactured "chemicals" are _______________, which can
be classified by production volume into bulk chemicals, fine chemicals and chemicals found in
research only:
A. Organometallic compound(s)
D. Mixture(s)
B. Chemical substance(s)
E. Chemical mixtures
C. Isomer(s)
F. None of the Above
27. _________________ are produced in very large quantities, usually with highly optimized
continuous processes and to a relatively low price.
A. Bulk chemical(s)
D. Compound(s)
B. Chemical(s)
E. A pure chemical compound
C. Mechanical processe(s)
F. None of the Above
28. _______________are produced at a high cost in small quantities for special low-volume
applications such as biocides, pharmaceuticals and specialty chemicals for technical
applications.
A. Organometallic compound(s)
D. Fine chemicals
B. Chemical mixtures
E. Chemical substance(s)
C. Isomer(s)
F. None of the Above
29. ________________are produced individually for research, such as when searching for
synthetic routes or screening substances for pharmaceutical activity. In effect, their price per
gram is very high, although they are not sold.
A. Bulk chemical(s)
D. Compound(s)
B. Chemical(s)
E. Research chemicals
C. Mechanical processe(s) F. None of the Above
30. The cause of the difference in production volume is the complexity of the molecular
structure of the chemical. Bulk chemicals are usually much less complex. While fine chemicals
may be more complex, many of them are simple enough to be sold as "_________________" in
the synthesis of more complex molecules targeted for single use, as named above.
A. Chemical bond(s)
D. Forms of energy
B. Chemical substance(s) E. Physical chemistry
C. Building blocks
F. None of the Above
31. The production of a chemical includes not only its synthesis but also its purification to
eliminate _______________________ involved in the synthesis. The last step in production
should be the analysis of batch lots of chemicals in order to identify and quantify the
percentages of impurities for the buyer of the chemicals.
A. Chemical bond(s)
D. Chemical mixtures
B. Chemical substance(s) E. Physical chemistry
C. Chemical(s)
F. None of the Above
Molecule
32. A molecule is the smallest indivisible portion of a pure chemical substance that has its
unique set of chemical properties, that is, its potential to undergo a certain set of
________________with other substances.
A. Tetra atomic molecule(s)
D. Existence of identifiable molecule(s)
B. Ions
E. Isolated chemical element(s)
C. Chemical reactions
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
33. Molecules are typically a set of atoms bound together by covalent bonds, such that the
structure is electrically neutral and _______________ are paired with other electrons either in
bonds or in lone pairs.
A. Molecule(s)
D. Charged polyatomic collection(s)
B. Ionic compounds
E. All valence electrons
C. Structure
F. None of the Above
34. Thus, molecules exist as electrically neutral units, unlike ions. When this rule is broken,
giving the "molecule" a charge, the result is sometimes named a molecular ion
or______________.
A. Tetra atomic molecule(s)
D. A polyatomic ion
B. Ions
E. Isolated chemical element(s)
C. A molecule
F. None of the Above
35. _________________ residing in solids (for example, common sulfate or nitrate ions) are
generally not considered "molecules" in chemistry.
A. Molecule(s)
D. Charged polyatomic collection(s)
B. Ionic compounds
E. A chemical substance
C. Structure
F. None of the Above
36. The "inert" or noble gas elements (helium, neon, argon, krypton, xenon and radon) are
composed of lone atoms as their smallest discrete unit, but the other isolated ____________
consist of either molecules or networks of atoms bonded to each other in some way.
A. Tetra atomic molecule(s) D. Existence of identifiable molecule(s)
B. Ions
E. Chemical element(s)
C. A molecule
F. None of the Above
37. _______________compose familiar substances such as water, air, and many organic
compounds like alcohol, sugar, gasoline, and the various pharmaceuticals.
A. Identifiable molecules
D. Existence of identifiable molecule(s)
B. Ions
E. Isolated chemical element(s)
C. A molecule
F. None of the Above
38. Not all substances or chemical compounds consist of discrete molecules, and indeed most
of the solid substances that make up the solid crust, mantle, and core of the Earth are chemical
compounds without _______________.
A. Molecule(s)
D. Charged polyatomic collection(s)
B. Ionic compounds
E. A chemical substance
C. Structure
F. None of the Above
39. These other types of substances, such as _______________and network solids, are
organized in such a way as to lack the existence of identifiable molecules per se. Instead, these
substances are discussed in terms of formula units or unit cells as the smallest repeating
structure within the substance.
A. Tetra atomic molecule(s) D. Existence of identifiable molecule(s)
B. Ions
E. Isolated chemical element(s)
C. Ionic compounds
F. None of the Above
(S) Means the answer can be plural or singular in nature
16
Chlorination 303 8/9/2015 Assignment
40. One of the main characteristics of a __________________ is its geometry often called its
structure.
A. Molecule(s)
D. Charged polyatomic collection(s)
B. Ionic compounds
E. A chemical substance
C. Structure
F. None of the Above
41. While the structure of diatomic, triatomic or tetra atomic molecules may be trivial, (linear,
angular pyramidal etc.)_____________, that are constituted of more than six atoms (of several
elements) can be crucial for its chemical nature.
A. Tetra atomic molecule(s) D. Existence of identifiable molecule(s)
B. Ions
E. The structure of polyatomic molecules
C. A molecule
F. None of the Above
Substance and Mixture
42. _____________________ is a kind of matter with a definite composition and set of
properties. A collection of substances is called a mixture. Examples of mixtures are air and
alloys.
A. Molecule(s)
D. Charged polyatomic collection(s)
B. Ionic compounds
E. A chemical substance
C. Structure
F. None of the Above
Mole and Amount of Substance
43. The mole is a unit of measurement that denotes an amount of substance (also
called_______________).
A. An amount of substance
D. Chemical amount
B. A triple point
E. Multipole balance
C. Crystal structure
F. None of the Above
Phase
44. In addition to the specific chemical properties that distinguish different chemical
classifications, chemicals can exist in several phases. For the most part, the chemical
classifications are independent of these _____________ classifications; however, some more
exotic phases are incompatible with certain chemical properties.
A. An ionic bond
D. Phase transition
B. Another atom
E. Bulk phase
C. Multiple solid phases
F. None of the Above
45. _______________of a chemical system that have similar bulk structural properties, over a
range of conditions, such as pressure or temperature.
A. An amount of substance
D. A phase is a set of states
B. A triple point
E. Multipole balance
C. Crystal structure
F. None of the Above
46. Physical properties, such as density and refractive index tend to fall within values
characteristic of the phase. The phase of matter is defined by______________, which is when
energy put into or taken out of the system goes into rearranging the structure of the system,
instead of changing the bulk conditions.
A. An ionic bond
D. The phase transition
B. Another atom
E. Bulk phase
C. Multiple solid phases
F. None of the Above
17
Chlorination 303 8/9/2015 Assignment
47. Sometimes the distinction between phases can be continuous instead of having a discrete
boundary, in this case the matter is considered to be in__________________. When three
states meet based on the conditions, it is known as a triple point and since this is invariant, it is
a convenient way to define a set of conditions.
A. An amount of substance D. A supercritical state
B. A triple point
E. Multipole balance
C. Crystal structure
F. None of the Above
48. The most familiar examples of phases are solids, liquids, and gases. Many substances
exhibit multiple solid phases. There are three phases of solid iron (alpha, gamma, and delta)
that vary based on_______________________.
A. An ionic bond
D. Phase transition
B. Another atom
E. Temperature and pressure
C. Multiple solid phases
F. None of the Above
49.
Another phase commonly encountered in the study of chemistry is
the____________________, which is the state of substances dissolved in aqueous solution
(that is, in water).
A. An amount of substance
D. Aqueous phase
B. A triple point
E. Multipole balance
C. Crystal structure
F. None of the Above
50. Less familiar phases include plasmas, _______________condensates and fermionic
condensates and the paramagnetic and ferromagnetic phases of magnetic materials. While
most familiar phases deal with three-dimensional systems, it is also possible to define analogs
in two-dimensional systems, which has received attention for its relevance to systems in
biology.
A. Bose–Einstein
D. Phase transition
B. Another atom
E. Bulk phase
C. Multiple solid phases
F. None of the Above
Bonding
51. Atoms sticking together in _____________are said to be bonded with one another. A
chemical bond may be visualized as the multipole balance between the positive charges in the
nuclei and the negative charges oscillating about them.
A. An amount of substance
D. Pressure or temperature
B. A triple point
E. Multipole balance
C. Molecules or crystals
F. None of the Above
52. More than simple attraction and repulsion, the energies and distributions characterize the
availability of an electron to bond to_______________.
A. Chemical element(s)
D. Photon
B. An electron
E. A chemical bond
C. Another atom
F. None of the Above
18
Chlorination 303 8/9/2015 Assignment
53. A chemical bond can be a covalent bond, an ionic bond, a hydrogen bond or just because
of Van der Waals force. Each of these kinds of bonds is ascribed to some potential. These
potentials create the interactions which hold atoms together in_____________.
A. Chemical element(s)
D. Molecules or crystals
B. An electron
E. A chemical bond
C. Another atom
F. None of the Above
54. ________________ is formed when a metal loses one or more of its electrons, becoming a
positively charged cation, and the electrons are then gained by the non-metal atom, becoming a
negatively charged anion.
A. An ionic bond
D. Phase transition
B. Another atom
E. Bulk phase
C. Multiple solid phases
F. None of the Above
Energy
55. In the context of chemistry, energy is an attribute of a substance as a consequence of its
atomic, molecular or aggregate structure. Since a ________________transformation is
accompanied by a change in one or more of these kinds of structures, it is invariably
accompanied by an increase or decrease of energy of the substances involved.
A. Chemical reaction(s)
D. Breaking of chemical bonds
B. Energy exchange
E. Chemical
C. Chemical equation
F. None of the Above
56. Some ____________ is transferred between the surroundings and the reactants of the
reaction in the form of heat or light; thus the products of a reaction may have more or less
energy than the reactants.
A. Oxidation
D. Reorganization of chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Energy
F. None of the Above
Reaction
57. During _____________, bonds between atoms break and form, resulting in different
substances with different properties.
A. Chemical reaction(s)
D. Breaking of chemical bonds
B. Energy exchange
E. Reaction mechanism(s)
C. Chemical equation
F. None of the Above
58. When a chemical substance is transformed as a result of its interaction with another
substance or with energy, a _________________is said to have occurred.
A. Oxidation
D. Reorganization of chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Energy
F. None of the Above
59. A _________________ is therefore a concept related to the "reaction" of a substance when
it comes in close contact with another, whether as a mixture or a solution; exposure to some
form of energy, or both.
A. Chemical reaction(s)
D. Breaking of chemical bonds
B. Energy exchange
E. Reaction mechanism(s)
C. Chemical equation
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
60. __________________ can result in the formation or dissociation of molecules, that is,
molecules breaking apart to form two or smaller molecules, or rearrangement of atoms within or
across molecules.
A. Oxidation
D. Reorganization of chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Energy
F. None of the Above
61. Chemical reactions usually involve the making or breaking of_______________.
A. Chemical reaction(s)
D. Chemical bonds
B. Energy exchange
E. Reaction mechanism(s)
C. Chemical equation
F. None of the Above
62. ________________ reduction, dissociation, acid-base neutralization and molecular rearrangement are some of the commonly used kinds of chemical reactions.
A. Oxidation
D. Reorganization of chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Energy
F. None of the Above
63. A chemical reaction can be symbolically depicted through a __________________. While
in a non-nuclear chemical reaction the number and kind of atoms on both sides of the equation
are equal, for a nuclear reaction this holds true only for the nuclear particles viz. protons and
neutrons.
A. Chemical reaction(s)
D. Breaking of chemical bonds
B. Energy exchange
E. Reaction mechanism(s)
C. Chemical equation
F. None of the Above
64. The sequence of steps in which the reorganization of ___________ may be taking place in
the course of a chemical reaction is called its mechanism.
A. Oxidation
D. Chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Energy
F. None of the Above
65. A chemical reaction can be envisioned to take place in a number of steps, each of which
may have a____________________.
A. Oxidation
D. Reorganization of chemical bonds
B. Chemical reaction(s)
E. Reaction in the form of heat or light
C. Different speed
F. None of the Above
66. Many reaction intermediates with variable stability can thus be envisaged during the course
of a reaction. Reaction mechanisms are proposed to explain the ___________and the relative
product mix of a reaction.
A. Chemical reaction(s)
D. Breaking of chemical bonds
B. Energy exchange
E. Kinetics
C. Chemical equation
F. None of the Above
20
Chlorination 303 8/9/2015 Assignment
Acidity and Basicity
67. A substance can often be classified as an acid or a base. There are several different
theories which explain acid-base behavior. The simplest is Arrhenius theory, which states than
an acid is a substance that produces ______________when it is dissolved in water, and a base
is one that produces hydroxide ions when dissolved in water.
A. Acid
D. pH measurement(s)
B. Alkalinity
E. Hydronium ions
C. pH
F. None of the Above
68. According to Brønsted–Lowry acid–base theory, ________________are substances that
donate a positive hydrogen ion to another substance in a chemical reaction; by extension, a
base is the substance which receives that hydrogen ion.
A. Measurement of Ph
D. Acids
B. pH
E. Acid-base behavior
C. (Solvated) hydronium ion
F. None of the Above
69. A third common theory is Lewis acid-base theory, which is based on the formation of new
chemical bonds. Lewis theory explains that an acid is a substance which is capable of accepting
a pair of electrons from another substance during the process of bond formation, while a base is
a substance which can provide a pair of electrons to form a new bond. According to this theory,
the crucial things being exchanged are__________________.
A. Acid
D. Charges
B. Alkalinity
E. Bond formation
C. pH
F. None of the Above
pH Section
70. In chemistry, _______________ is a measure of the acidity or basicity of an aqueous
solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater
than 7 are basic or alkaline. Pure water has a pH very close to 7.
A. Measurement of Ph
D. Brønsted–Lowry acid–base theory
B. pH
E. Acid-base behavior
C. (Solvated) hydronium ion
F. None of the Above
71. ___________are determined using a concentration cell with transference, by measuring the
potential difference between a hydrogen electrode and a standard electrode such as the silver
chloride electrode.
A. Primary pH standard values
D. pH measurement(s)
B. Alkalinity
E. Measurement of pH
C. pH
F. None of the Above
72. ________________________for aqueous solutions can be done with a glass electrode and
a pH meter, or using indicators.
A. Primary pH standard values
D. pH measurement(s)
B. Alkalinity
E. Measurement of pH
C. pH
F. None of the Above
21
Chlorination 303 8/9/2015 Assignment
73. _____________________ are important in medicine, biology, chemistry, agriculture,
forestry, food science, environmental science, oceanography, civil engineering, chemical
engineering, nutrition, water treatment & water purification, and many other applications.
A. Primary pH standard values
D. pH measurement(s)
B. Alkalinity
E. Measurement of pH
C. pH
F. None of the Above
74. Mathematically, pH is the negative logarithm of the activity of the (solvated) hydronium ion,
more often expressed as the measure of the___________________.
A. Primary pH standard values
D. pH measurement(s)
B. Alkalinity
E. Measurement of pH
C. Hydronium ion concentration
F. None of the Above
Alkalinity
75. Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize
an _________________.
A. Acid
D. pH measurement(s)
B. Base
E. Bond formation
C. pH
F. None of the Above
76. Measuring alkalinity is important in determining a stream's ability to neutralize acidic
pollution from rainfall or wastewater. It is one of the best measures of the sensitivity of the
stream to acid inputs. There can be long-term changes in the _________________ of rivers and
streams in response to human disturbances.
A. Acid
D. pH measurement(s)
B. Alkalinity
E. Bond formation
C. pH
F. None of the Above
pH Definition and Measurement
77. pH is defined as the decimal logarithm of the reciprocal of the_____________, aH+, in a
solution.
A. Hydrogen ion activity
D. Brønsted–Lowry acid–base theory,
B. pH
E. Acid-base behavior
C. (Solvated) hydronium ion
F. None of the Above
78. When more than two buffer solutions are used the electrode is calibrated by fitting observed
pH values to a straight line with respect to standard buffer values. Commercial standard buffer
solutions usually come with information on the value at 25 °C and a correction factor to be
applied for other temperatures. The pH scale is logarithmic and therefore pH is___________.
A.
Universal indicator
D. Excess of alkaline earth metal concentrations
B.
A dimensionless quantity
E. A set of non-linear simultaneous equations
C.
Spectrophotometer
F. None of the Above
pH Indicators
79. _______________may
changes with pH.
A.
Indicators
B.
pH
C.
Spectrophotometer
be used to measure pH, by making use of the fact that their color
D. Excess of alkaline earth metal concentrations
E. A set of non-linear simultaneous equations
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
80. _________________of the color of a test solution with a standard color chart provides a
means to measure pH accurate to the nearest whole number.
A.
Universal indicator
D. Visual comparison
B.
pH
E. A set of non-linear simultaneous equations
C.
Spectrophotometer F. None of the Above
81. More precise measurements are possible if the color is measured spectrophotometrically,
using a_________________ .
A.
Universal indicator
D. Excess of alkaline earth metal concentrations
B.
Colorimeter of spectrophotometer E. A set of non-linear simultaneous equations
C.
Spectrophotometer
F. None of the Above
82. Universal indicator consists of a mixture of indicators such that there is a continuous color
change from about pH 2 to pH 10. __________________ is made from absorbent paper that
has been impregnated with universal indicator.
A.
Universal indicator
D. Excess of alkaline earth metal concentrations
B.
Colorimeter of spectrophotometer E. A set of non-linear simultaneous equations
C.
Spectrophotometer
F. None of the Above
Calculations of pH
83. The calculation of the pH of a solution containing acids and/or bases is an example of a
chemical speciation calculation, that is, a mathematical procedure for calculating the
concentrations of all chemical species that are present in the solution. The complexity of the
procedure depends on the____________________.
A. Universal indicator
D. Excess of alkaline earth metal concentrations
B. pH
E. A set of non-linear simultaneous equations
C. Nature of the solution
F. None of the Above
84. For strong acids and bases no calculations are necessary except in extreme situations. The
pH of a solution containing a weak acid requires the solution of a quadratic equation. The pH of
a solution containing a weak base may require the______________. The general case requires
the solution of a set of non-linear simultaneous equations.
A. Solution of a cubic equation
D. Excess of alkaline earth metal concentrations
B. pH
E. A set of non-linear simultaneous equations
C. Spectrophotometer
F. None of the Above
Strong Acids and Bases
85. Strong acids and bases are compounds that, for practical purposes, are completely
dissociated in water. Under normal circumstances this means that the concentration of
hydrogen ions in acidic solution can be taken to be equal to the concentration of the acid. The
pH is then equal to minus the logarithm of__________.
A. The concentration value D. Excess of alkaline earth metal concentrations
B. The pH
E. A set of non-linear simultaneous equations
C. The Spectrophotometer F. None of the Above
23
Chlorination 303 8/9/2015 Assignment
Alkalinity
Introduction
86. Alkalinity of water is its acid-neutralizing capacity. It is the sum of all the titratable bases.
The measured value may vary significantly with the ___________used.
A. Acid
D. pH measurement(s)
B. Alkalinity E. End-point pH
C. pH
F. None of the Above
87. Alkalinity is a measure of _________and can be interpreted in terms of specific substances
only when the chemical composition of the sample is known.
A. Universal indicator
D. Excess of alkaline earth metal concentrations
B. pH
E. A set of non-linear simultaneous equations
C. An aggregate property of water F. None of the Above
88. Alkalinity is significant in many uses and treatments of natural waters and wastewaters.
Because the alkalinity of ______________ it is taken as an indication of the concentration of
these constituents. The measured values also may include contributions from borates,
phosphates, silicates or other bases if these are present.
A. Acid
D. pH measurement(s)
B. Alkalinity
E. Bond formation
C. pH
F. None of the Above
89. Alkalinity in excess of _________ is significant in determining the suitability of water for
irrigation.
A. Universal indicator
D. Alkaline earth metal concentrations
B. pH
E. A set of non-linear simultaneous equations
C. Spectrophotometer
F. None of the Above
90. __________________ measurements are used in the interpretation and control of water
and wastewater treatment processes.
A. Acid
D. A set of non-linear simultaneous equation
B. Alkalinity
E. Bond formation
C. pH
F. None of the Above
Hard Water Section
91. Water contains various amounts of__________________, some of which impart a quality
known as hardness. Consumers frequently complain about problems attributed to hard water,
such as the formation of scale on cooking utensils and hot water heaters.
A. Water hardness
D. Calcium (Ca) and magnesium (Mg)
B. Carbonate hardness
E. Dissolved minerals
C. The calcium-magnesium distinction
F. None of the Above
Occurrence of Hard Water
92. Hard water is caused by soluble, divalent, _________, (positive ions having valence of 2).
The principal chemicals that cause water hardness are calcium (Ca) and magnesium (Mg).
A. Water hardness
D. Calcium (Ca) and magnesium (Mg)
B. Metallic cations
E. Noncarbonate hardness
C. Carbon dioxide (CO2)
F. None of the Above
24
Chlorination 303 8/9/2015 Assignment
Chlorine Basics
93. In 1774, in his small experimental laboratory, Swedish pharmacist Carl Wilhem Scheele
released a few drops of hydrochloric acid onto a piece of manganese dioxide. Within seconds, a
greenish-yellow gas arose. Although he had no idea at the time, he had just
discovered_____________.
A. Moon germs
D. Manganese dioxide
B. Bacteria and viruses
E. Basic building blocks of our planet
C. Chlorine
F. None of the Above
94. The fact that the greenish-yellow gas was actually an element was only recognized several
decades later by English chemist Sir Humphrey Davy. Until that time, people were convinced
that the gas was a ________________.
A. Chlorine chemistry
D. Economical germ-killers
B. Compound of oxygen
E. Life-threatening infections, viruses, and bacteria
C. Chlorine's powerful disinfectant qualities F. None of the Above
95. Davy gave the element its name on the basis of the Greek word khloros, for
_______________. In 1810 he suggested the name "chloric gas" or "chlorine."
A. Economical germ-killers
D. Manganese dioxide
B. Bacteria and viruses killer
E. Basic building blocks
C. Greenish-yellow
F. None of the Above
96. One of the most effective and_______________, chlorine also destroys and deactivates a
wide range of dangerous germs in homes, hospitals, swimming pools, hotels, restaurants, and
other public places.
A. Chlorine chemistry
D. Economical germ-killers
B. Compound of oxygen
E. Life-threatening infections, viruses, and bacteria
C. Chlorine's powerful disinfectant qualities F. None of the Above
97. Chlorine's powerful disinfectant qualities come from its ability to bond with and destroy the
outer surfaces of _________________.
A. Moon germs
D. Manganese dioxide
B. Bacteria and viruses
E. Basic building blocks of our planet
C. Salmonella and E. coli
F. None of the Above
98. First used as a germicide to prevent the spread of "child bed fever" in the maternity wards
of Vienna General Hospital in Austria in 1846, chlorine has been one of society's most potent
weapons against a wide array of _______________________ for 150 years.
A. Bacteria and viruses
D. Economical germ-killers
B. Compound of oxygen
E. Life-threatening infections, viruses, and bacteria
C. Chlorine's powerful disinfectant qualities F. None of the Above
99. When the first men to set foot on the moon returned to earth (Apollo 11 mission: 24.7.69) a
hypochlorite solution was chosen as one of the disinfectants for destroying any possible
__________.
A. Moon germs
D. Manganese dioxide
B. Bacteria and viruses
E. Basic building blocks of our planet
C. Salmonella and E. coli
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Chlorination Introduction
100. Microorganisms can be found in raw water from rivers, lakes and groundwater. While not
all microorganisms are harmful to human health, there are some that may cause diseases in
humans. These are called________________.
A. Epidemics
D. Pathogens
B. Waterborne disease
E. Microscopic agents of many diseases
C. Microorganisms
F. None of the Above
101. Pathogens present in water can be transmitted through a drinking water distribution
system, causing _______________in those who consume it.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Waterborne disease
C. Cholera, polio, typhoid, hepatitis F. None of the Above
102. Water chlorination is the process of adding the ___________to water as a method of
water purification to make it fit for human consumption as drinking water.
A. Halogen
D. Chlorine
B. Element chlorine
E. Hypochlorous acid
C. Chlorine as a disinfectant
F. None of the Above
103. Water that has been treated with chlorine is effective in preventing the spread of
_________.
A. Epidemics
D. Oxidation of organic molecules
B. Waterborne disease
E. Microscopic agents of many diseases
C. Microorganisms
F. None of the Above
104. A large amount of research and many studies have been conducted to ensure success in
water treatment plants and various water producing wells using ______________.
A. Halogen
D. Chlorine
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant
F. None of the Above
105. A leading advantage of chlorination is that it has proven effective against bacteria and
viruses; however, it cannot inactivate all microbes. Some ____________are resistant to the
effects of chlorine.
A. Protozoan cysts
D. Oxidation of organic molecules
B. Waterborne disease
E. Microscopic agents of many diseases
C. Microorganisms
F. None of the Above
106. As a halogen, chlorine is a highly efficient disinfectant, and is added to public water
supplies to kill disease-causing pathogens, such as_______________, that commonly grow in
water supply reservoirs, on the walls of water mains and in storage tanks.
A. Epidemics
D. Oxidation of organic molecules
B. Waterborne disease
E. Microscopic agents of many diseases
C. Bacteria, viruses and protozoans F. None of the Above
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Chlorination 303 8/9/2015 Assignment
107. The microscopic agents of many diseases such as ____________killed countless people
annually before disinfection methods were employed routinely.
A. Epidemics
D. Oxidation of organic molecules
B. Waterborne disease
E. Cholera, typhoid fever, and dysentery
C. Microorganisms
F. None of the Above
108. _________ is obtained from salt (NaCl). It is a gas at atmospheric pressures but liquefies
under pressure. The liquefied gas is transported and used as such.
A. Halogen
D. Chlorine
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant F. None of the Above
109. As a strong oxidizing agent, chlorine kills via the______________.
A. Halogen
D. Oxidation of organic molecules
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant F. None of the Above
110. Chlorine and its _______________are neutrally charged and therefore easily penetrate
the negatively charged surface of pathogens. It is able to disintegrate the lipids that compose
the cell wall and react with intracellular enzymes and proteins, making them nonfunctional.
Microorganisms then either die or are no longer able to multiply.
A. Halogen
D. Hydrolysis product hypochlorous acid
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant F. None of the Above
111. In the past 30 years, the Safe Drinking Water Act (SDWA) has been highly effective in
protecting public health and has also evolved to respond to new and emerging threats to safe
drinking water.
A. Cryptosporidium
D. Emerging threats to safe drinking water
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
112. Disinfection of drinking water is one of the major public health advances in the 20th
century. One hundred years ago, _______________were common through American cities;
disinfection was a major factor in reducing these epidemics.
A. Epidemics
D. Oxidation of organic molecules
B. Waterborne disease
E. Typhoid and cholera epidemics
C. Microorganisms
F. None of the Above
113. However, the disinfectants themselves can react with naturally-occurring materials in the
water to form unintended byproducts which may pose health risks. In addition, in the past ten
years, we have learned that there are specific microbial pathogens, such as ____________,
which can cause illness and is resistant to traditional disinfection practices.
A. Cryptosporidium
D. Emerging threats to safe drinking water
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Chlorination Principles
114. When dissolved in water, chlorine converts to an equilibrium mixture of chlorine,
_________.
A. Cryptosporidium
D. Emerging threats to safe drinking water
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
115. In acidic solution, the major species are Cl2 and HOCl while in alkaline solution effectively
only ClO- is present. Very small concentrations of _____________are also found. We will cover
this subject in greater detail.
A. Dibromochloromethane D. An antioxidant formulation of Vitamin C
B. Bromoform
E. ClO2-, ClO3-, ClO4C. Cl2 and HOCl
F. None of the Above
Shock Chlorination
116. ______________is a process used in many swimming pools, water wells, springs, and
other water sources to reduce the bacterial and algal residue in the water.
A. Cryptosporidium
D. Shock chlorination
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
117. Shock chlorination is performed by mixing a large amount of sodium hypochlorite, which
can be in the form of a powder or a liquid such as_____________, into the water. Water that is
being shock chlorinated should not be swum in or drunk until the sodium hypochlorite count in
the water goes down to three ppm or less.
A. Cryptosporidium
D. Chlorine bleach
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
Drawbacks to Water Chlorination
118. Disinfection by chlorination can be problematic, in some circumstances. ________ can
react with naturally occurring organic compounds found in the water supply to produce
compounds known as disinfection byproducts (DBPs).
A. Halogen
D. Chlorine
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant
F. None of the Above
119. The most common DBPs are trihalomethanes (THMs) and__________________.
A. Haloacetic acids (HAAs)
D. Chlorine
B. Water chlorination
E. Hypochlorous acid
C. Chlorine as a disinfectant
F. None of the Above
120. _________________are the main disinfectant by-products created from chlorination with
two different types, bromoform and dibromochloromethane, which are mainly responsible for
health hazards.
A. Dibromochloromethane D. An antioxidant formulation of Vitamin C
B. Trihalomethanes
E. A major public health concern
C. Cl2 and HOCl
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
121. Their effects depend strictly on the duration of their exposure to the chemicals and the
amount ingested into the body. In high doses, ____________ mainly slows down regular brain
activity, which is manifested by symptoms such as sleepiness or sedation.
A. Cryptosporidium
D. Dibromochloromethane
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
122. Chronic exposure of _____________can cause liver and kidney cancer, as well as heart
disease, unconsciousness or death in high doses.
A. Dibromochloromethane D. An antioxidant formulation of Vitamin C
B. Bromoform
E. Both bromoform and dibromochloromethane
C. Cl2 and HOCl
F. None of the Above
123. Due to the________________, drinking water regulations across the developed world
require regular monitoring of the concentration of these compounds in the distribution systems
of municipal water systems.
A. Halogen
D. Chlorine
B. Water chlorination
E. Potential carcinogenicity of these compounds
C. Chlorine as a disinfectant F. None of the Above
124. Chlorination of swimming pools can have adverse effects on the skin and hair of
swimmers due to chlorine's oxidizing properties; various remedies have been developed, most
recently_________.
A. Dibromochloromethane D. An antioxidant formulation of Vitamin C
B. Bromoform
E. A major public health concern
C. Cl2 and HOCl
F. None of the Above
Understanding Waterborne Viruses
125. ________________may be present in fecal-contaminated waters.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis F. None of the Above
126. Treatment processes and watershed management strategies designed on the basis of
bacteriological criteria do not necessarily protect against ______________because viruses are
generally more persistent in the environment and are not removed as completely by treatment.
A. F-specific coliphages
D. Viruses
B. Indicators of fecal contamination E. Viral infection
C. Enteric viruses
F. None of the Above
127. In addition, because of their smaller size, viruses (0.023 to 0.080 µm) are transported
further in ground water than bacteria (0.5 to 3µ m) or ______________(4 to 15 µm). Because of
the importance of viruses as a major public health concern, new methods for detection of enteric
viruses and the search for indicators of viral contamination continue.
A. Protozoan pathogens
D. Viruses
B. Indicators of fecal contamination E. Microorganisms
C. Enteric viruses
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
128. The current method for culturing ____________ under the ICR (U.S. Environmental
Protection Agency, 1996c) is recognized as being difficult to implement; therefore, the ICR does
not preclude the use of additional methods for research purposes. In addition, cell-culture
methods are not available or suitable for all viruses of public health concern.
A. Protozoan pathogens
D. Viruses
B. Indicators of fecal contamination E. Microorganisms
C. Enteric viruses
F. None of the Above
129. One method, reverse-transcriptase-polymerase chain reaction (RT-PCR), a gene-probe
method that amplifies and recognizes the nucleic acids of____________, has been adequately
validated by the USEPA (G. Shay Fout, U.S. Environmental Protection Agency, written
commun., 1997) and is becoming widely used for environmental monitoring of enteric viruses.
The RTPCR method, however, does not determine the infectivity of the virus, and it is
technically demanding, time consuming, and costly for routine use.
A. Enteric viruses
D. Indicators of viral contamination
B. F-specific coliphages
E. Coliphages are bacteriophages
C. Target viruses
F. None of the Above
130. Because monitoring of enteric viruses is recognized as being difficult and time consuming,
some researchers advocate the use of coliphage as___________________.
A. F-specific coliphages
D. Viruses
B. Indicators of fecal contamination E. Indicator viruses for fecal contamination
C. Enteric viruses
F. None of the Above
131. _________________ that infect and replicate in coliform bacteria. The two main groups of
coliphages that are considered as candidates for viral indicators are somatic and F-specific
coliphages.
A. Enteric viruses
D. Indicators of viral contamination
B. F-specific coliphages
E. Coliphages are bacteriophages
C. Viruses
F. None of the Above
132. Somatic coliphages infect coliform bacteria by attachment to the outer cell membrane or
cell wall. They are widely distributed in both fecal-contaminated and uncontaminated waters;
therefore, they may not be reliable __________________.
A. F-specific coliphages
D. Viruses
B. Indicators of fecal contamination E. Microorganisms
C. Enteric viruses
F. None of the Above
133. ________________ attach only to the F-pilus of coliforms that carry the F+ plasmid; F-pili
are made only by bacteria grown at higher temperatures.
A. Enteric viruses
D. Indicators of viral contamination
B. F-specific coliphages
E. Coliphages are bacteriophages
C. Viruses
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
134. Hence, _______________ found in environmental samples presumably come from warmblooded animals or sewage. Although somatic and F-specific coliphages are not consistently
found in feces, they are found in high numbers in sewage and are thought to be reliable
indicators of the sewage contamination of waters (International Association of Water Pollution
Research and Control, 1991).
A. F-specific coliphages
D. Viruses
B. Indicators of fecal contamination E. Microorganisms
C. Enteric viruses
F. None of the Above
135. Coliphage is also recognized to be representative of the survival and transport of
___________ in the environment. To date, however, coliphage has not been found to correlate
with the presence of pathogenic viruses.
A. Enteric viruses
D. Indicators of viral contamination
B. F-specific coliphages
E. Coliphages are bacteriophages
C. Viruses
F. None of the Above
Sampling Procedures
Streamwater Sample Collection
136. When designing a sampling plan, consider that the spatial and temporal distribution of
microorganisms in surface water can be as variable as the distribution of ___________because
microorganisms are commonly associated with solid particles.
A. Suspended sediment
D. Viruses
B. Indicators of fecal contamination
E. Microorganisms
C. Enteric viruses
F. None of the Above
137. The standard samplers used in by the majority of samplers can be used to collect
streamwater samples for bacterial and viral indicators, __________providing that the equipment
coming in contact with the water is properly cleaned and sterilized.
A. Cryptosporidium, and Giardia
D. Cryptosporidium
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
Cryptosporidium and Giardia Analysis
138. For Cryptosporidium and Giardia analysis by Method 1623 (U.S. Environmental Protection
Agency, 1999c), collect 10 L of streamwater for each protozoan pathogen using standard
sampling techniques described in Myers and Sylvester (1997). Special sterilization procedures
are needed for equipment used in the collection of samples for ________________. Autoclaving
is not effective in neutralizing the epitopes on the surfaces of the oocysts and cysts that will
react with the antibodies used for detection.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Cryptosporidium and Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
139. Submerge the equipment in a vessel containing 12 percent hypochlorite solution for 30
minutes. Wash the equipment free of residual sodium hypochlorite solution with three rinses of
filter-sterilized water; do not de-chlorinate the equipment using ____________.
A. Dibromochloromethane D. Sodium hypochlorite solution
B. Bromoform
E. Sodium thiosulfate
C. Cl2 and HOCl
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
140. Composite the sample in a 10-L cubitainer that is pre-sterilized by the manufacturer. The
cubitainer is sent in a cardboard box to laboratory for ___________analysis. The sample does
not have to be kept on ice during transport.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
Understanding Bacteriophage
141. Bacteriophages may have a lytic cycle or a lysogenic cycle, and a few viruses are capable
of carrying out both. With lytic phages such as the T4 phage, ______________are broken open
(lysed) and destroyed after immediate replication of the virion. As soon as the cell is destroyed,
the phage progeny can find new hosts to infect. Lytic phages are more suitable for phage
therapy.
A. Lysogenic cycle D. Phage virions
B. Bacterial cells
E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
142. Some _______________undergo a phenomenon known as lysis inhibition, where
completed phage progeny will not immediately lyse out of the cell if extracellular phage
concentrations are high. This mechanism is not identical to that of temperate phage going
dormant and is usually temporary.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. Lytic phages
C. Myovirus bacteriophages
F. None of the Above
143. In contrast, the _____________ does not result in immediate lysing of the host cell. Those
phages able to undergo lysogeny are known as temperate phages.
A. Lysogenic cycle D. Phage virions
B. Virus
E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
144. Their viral genome will integrate with ________________and replicate along with it fairly
harmlessly, or may even become established as a plasmid.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. Viral genome
C. Host DNA
F. None of the Above
145. The virus remains dormant until host conditions deteriorate, perhaps due to depletion of
nutrients; then, the ____________________(known as prophages) become active. At this point
they initiate the reproductive cycle, resulting in lysis of the host cell.
A. Lysogenic cycle
D. Phage virions
B. Endogenous phages
E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
146. As the lysogenic cycle allows the host cell to continue to survive and reproduce, the virus
is reproduced in all of the cell’s offspring. An example of a bacteriophage known to follow the
lysogenic cycle and the lytic cycle is the ____________________.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
147. Sometimes prophages may provide benefits to the host bacterium while they are dormant
by adding new functions to the bacterial genome in a phenomenon called lysogenic conversion.
An eminent example is the conversion of a harmless strain of _____________by a phage into a
highly virulent one, which causes cholera.
A. Lysogenic cycle D. Phage virions
B. The virus
E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
Attachment and Penetration
148. To enter a host cell, _____________________attach to specific receptors on the surface
of bacteria, including lipopolysaccharides, teichoic acids, proteins, or even flagella. This
specificity means a bacteriophage can infect only certain bacteria bearing receptors to which
they can bind, which in turn determines the phage's host range.
A. Podoviruses
D. Bacteriophages
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
149. Host growth conditions also influence the ability of the phage to attach and invade them.
As ____________ do not move independently, they must rely on random encounters with the
right receptors when in solution (blood, lymphatic circulation, irrigation, soil water, etc.).
A. Lysogenic cycle D. Phage virions
B. The virus
E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
150. ______________ use a hypodermic syringe-like motion to inject their genetic material into
the cell. After making contact with the appropriate receptor, the tail fibers flex to bring the base
plate closer to the surface of the cell; this is known as reversible binding.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
151. Once attached completely, irreversible binding is initiated and the tail contracts, possibly
with the help of ATP present in the tail, injecting __________through the bacterial membrane.
A. Lysogenic cycle D. Phage virions
B. Genetic material E. Myovirus bacteriophages
C. Vibrio cholerae
F. None of the Above
152. ______________ lack an elongated tail sheath similar to that of a myovirus, so they
instead use their small, tooth-like tail fibers to enzymatically degrade a portion of the cell
membrane before inserting their genetic material.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Virions
153. _________________is a complete functional virus that has the capacity to infect living
tissue. This means that it includes the genetic material, the capsid, the enveloppe and the
membrane proteins that allow the virus to bind to its host and enter it. A virus will not have an
enveloppe within a cell.
A. Podoviruses
D. Phage lambda of E. coli
B. Phage's host range
E. A virion
C. Myovirus bacteriophages
F. None of the Above
154. If the cell was burst artificially, then these virus particles cannot be called virion because
they will lack certain proteins that will make them infectious even though the ___________is
present. Not all viruses have enveloppes, but most viruses have certain proteins that are
necessary to permit them to enter the host cell.
A. Podoviruses
D. Genetic material
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
155. Biomolecules found in virions: genetic material, _____________, single or double
stranded, nucleoprotein capsid, maybe an enveloppe usually receptor proteins or enzymes that
permit binding or entry into the host. A viroid is a plant pathogen consisting of a circular piece of
RNA without a protein coat.
A. Either DNA or RNA
D. Phage lambda of E. coli
B. Phage's host range
E. Viral genome
C. Myovirus bacteriophages
F. None of the Above
Chlorine Gas (Some questions may appear to repat, this is for QA/QC purposes)
156. Upon introduction into the water stream, chlorine hydrolyzes into _____________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
157. This hydrolization provides the active toxicant, _________, which is pH-dependent. In
alkaline cooling systems, it readily dissociates to form the hypochlorite ion (OCl-).
A. HCl
D. pH of 7.0 than at pH 8.5
B. HOCl
E. the hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
158. This dissociation phenomenon is important to remember when working with systems that
will operate at a higher pH. In alkaline conditions, _____________becomes the predominant
species and lacks the biocidal efficacy of the non-dissociated form.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. OClF. None of the Above
159. Considerably more __________ is present at a pH of 7.0 than at pH 8.5.
A. HCl
D. pH of 7.0 than at pH 8.5
B. HOCl
E. the hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
160. It is also widely known that chlorine is non-selective, making it very sensitive to
contamination from either cooling water makeup or from in-plant process leaks.____________,
organic acids and organic compounds, sulfides, iron and manganese all easily react with HOCl.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Ammonia
F. None of the Above
161. The amount of chlorine needed to react with these contamination species is referred to as
_____________and it must be satisfied before active HOCl is available to provide a free
chlorine residual.
A. Chlorine demand
D. pH of 7.0 than at pH 8.5
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
162. The combination of high chlorine demand in process-contaminated systems and the
dissociation process in alkaline systems creates the need for greater chlorine feed to obtain the
same microbial efficacy. This results in a higher concentration of ______________in the cooling
system.
A. Chlorine
D. HCl
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. Bromoform
F. None of the Above
163. Since ___________ removes alkalinity, pH depression and system corrosion could occur.
In low pH water the passive metal oxide layers protecting the metal may resolubulize, exposing
the surface to corrosion.
A. HCl
D. pH of 7.0 than at pH 8.5
B. HOCl
E. the hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
164. At free mineral acidity (pH <4.3), many passivating inhibitors become ineffective, and
corrosion will proceed rapidly. Increased chloride may also have a negative impact on system
corrosion. _______________can damage or penetrate the passive oxide layer, leading to
localized damage of the metal surface.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Hypochlorous acid (HOCl), and hydrochloric acid (HCl)
C. The chloride ion (Cl-)
F. None of the Above
165. High chlorine concentrations have also been shown to directly attack traditional organicbased corrosion inhibitors. When these inhibitors are "deactivated," the metal surface would
then be susceptible to corrosion. Process Safety Management (PSM) guidelines dictated by the
U.S. Occupational Safety and Health Administration (OSHA), discharge problems related to
____________such as trihalomethane (THM), dezincification of admiralty brass and
delignification of cooling tower wood are other significant concerns associated with the use of
chlorine.
A. Chlorinated organic compounds
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
35
Chlorination 303 8/9/2015 Assignment
Pathophysiology
166. Chlorine is a greenish-yellow, noncombustible gas at room temperature and atmospheric
pressure. The intermediate ___________of chlorine accounts for its effect on the upper airway
and the lower respiratory tract.
A. Generation of free oxygen radicals
D. Water solubility
B. Chlorine gas
E. The odor threshold for chlorine
C. Hydrochloric acid
F. None of the Above
167. Exposure to ____________ may be prolonged because its moderate water solubility may
not cause upper airway symptoms for several minutes. In addition, the density of the gas is
greater than that of air, causing it to remain near ground level and increasing exposure time.
A. Hydrochloric acid D. The chemical species produced
B. Chlorine gas
E. Plasma exudation
C. The gas
F. None of the Above
168. The odor threshold for chlorine is approximately 0.3-0.5 parts per million (ppm); however,
distinguishing toxic air levels from ___________may be difficult until irritative symptoms are
present.
A. Generation of free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. Permissible air levels
C. Hydrochloric acid
F. None of the Above
Mechanism of Activity
169. The mechanisms of the above biological activity are poorly understood and the
predominant anatomic site of injury may vary, depending on the ____________produced.
A. Hydrochloric acid
D. Chemical species
B. Chlorine gas
E. Plasma exudation
C. Gas
F. None of the Above
170. Cellular injury is believed to result from the oxidation of functional groups in cell
components, from reactions with tissue water to form_______, and from the generation of free
oxygen radicals.
A. Generation of free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. Hypochlorous and hydrochloric acid
C. Hydrochloric acid
F. None of the Above
171. Although the idea that ________ causes direct tissue damage by generating free oxygen
radicals was once accepted, this idea is now controversial.
A. Hydrochloric acid D. The chemical species produced
B. Chlorine
E. Plasma exudation
C. The gas
F. None of the Above
172. __________ comes out of the cylinder through a gas regulator. The cylinders are on a
scale that operators use to measure the amount used each day. The chains are used to
prevent the tanks from falling over.
A. Hydrochloric acid
D. The chemical species produced
B. Chlorine gas
E. Plasma exudation
C. The gas
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
173. ________________ is stored in vented rooms that have panic bar equipped doors.
A. Generation of free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. The odor
C. Hydrochloric acid
F. None of the Above
Solubility Effects
174. _____________acid is highly soluble in water. The predominant targets of the acid are the
epithelia of the ocular conjunctivae and upper respiratory mucus membranes.
A. Hydrochloric
D. Hypochlorous
B. Sulfuric
E. Nitric
C. Some
F. None of the Above
175. Hypochlorous acid is also highly water soluble with an injury pattern similar to_________.
A. Hydrochloric acid
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
176. __________may account for the toxicity of elemental chlorine and hydrochloric acid to the
human body.
A. HCl
D. pH of 7.0 than at pH 8.5
B. Hypochlorous acid
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
Early Response to Chlorine Gas
177. Chlorine gas, when mixed with ammonia, reacts to form___________. In the presence of
water, chloramines decompose to ammonia and hypochlorous acid or hydrochloric acid.
A. Generation of free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. Chloramine gas
C. Hydrochloric acid
F. None of the Above
178. The early response to ____________depends on the (1) concentration of chlorine gas, (2)
duration of exposure, (3) water content of the tissues exposed, and (4) individual susceptibility.
A. Chlorine exposure
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. The odor threshold for chlorine
C. Hydrochloric acid
F. None of the Above
Immediate Effects
179. The immediate effects of ___________ toxicity include acute inflammation of the
conjunctivae, nose, pharynx, larynx, trachea, and bronchi.
A. Hydrochloric acid
D. The chemical species produced
B. Chlorine gas
E. Chlorine exposure
C. The gas
F. None of the Above
180. Irritation of the airway mucosa leads to local edema secondary to active arterial and
capillary hyperemia. ________________ results in filling the alveoli with edema fluid, resulting
in pulmonary congestion.
A. Hydrochloric acid
D. The chemical species produced
B. Chlorine gas
E. Plasma exudation
C. The gas
F. None of the Above
37
Chlorination 303 8/9/2015 Assignment
Pathological Findings
181. Chlorine is a highly reactive gas. It is a______________. Chlorine is produced in very
large amounts (23 billion pounds in 1992) by eighteen companies in the United States.
A. HCl
D. Chlorine gas fumes
B. HOCl
E. Naturally occurring element
C. High chlorine concentrations
F. None of the Above
182. US demand for chlorine is expected to increase slightly over the next several years and
then decline. The expected decline in US demand is due to environmental concerns
for_________.
A. Chlorinated organic chemicals D. Chlorine gas fumes
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
183. The largest users of chlorine are companies that make ______________and other
chlorinated solvents, polyvinyl chloride (PVC) resins, chlorofluorocarbons, and propylene oxide.
Paper companies use chlorine to bleach paper.
A. HCl
D. Ethylene dichloride
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
184. Water and wastewater treatment plants use _____________to reduce water levels of
microorganisms that can spread disease to humans.
A. HCl
D. Chlorine
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
185. Exposure to chlorine can occur in the workplace or in the environment following releases
to air, water, or land. People who use laundry bleach and swimming pool chemicals containing
___________ are usually not exposed to chlorine itself.
A. HCl
D. Chlorine gas fumes
B. Chlorine products
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
186. Chlorine is generally found only in industrial settings. ___________ enters the body
breathed in with contaminated air or when consumed with contaminated food or water. It does
not remain in the body due to its reactivity.
A. HCl
D. Chlorine
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
Some questions appear to repeat for QA/QC purposes
187. Chlorine gas is greenish yellow in color and very toxic. It is heavier than air and will
therefore sink to the ground if released from its container. It is the toxic effect of ________ that
makes it a good disinfectant, but it is toxic to more than just waterborne pathogens; it is also
toxic to humans. It is a respiratory irritant and it can also irritate skin and mucus membranes.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
38
Chlorination 303 8/9/2015 Assignment
188. Exposure to high volumes of ___________ can cause serious health problems, including
death.
A. HCl
D. Chlorine gas fumes
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
189. However, it is important to realize that ____________, once entering the water, changes
into hypochlorous acid and hypochlorite ions, and therefore its human toxic properties are not
found in the drinking water we consume.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
190. Chlorine gas is sold as a compressed liquid, which is amber in color. Chlorine, as
a____________, is heavier (more dense) than water. If the chlorine liquid is released from its
container it will quickly return back to its gas state.
A. HCl
D. Chlorine gas fumes
B. HOCl
E. The hypochlorite ion (OCl-)
C. Liquid
F. None of the Above
191. Chlorine gas is the least expensive form of chlorine to use. The typical amount of chlorine
gas required for water treatment is 1-16 mg/L of water. Different amounts of chlorine gas are
used depending on the _____________that needs to be treated. If the water quality is poor, a
higher concentration of chlorine gas will be required to disinfect the water if the contact time
cannot be increased.
A. HCl
D. pH of 7.0 than at pH 8.5
B. Quality of water
E. the hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
Where Chlorine is Found and How it is Used
192. Chlorine is one of the most commonly manufactured chemicals in the United States. Its
most important use is as a bleach in the manufacture of paper and cloth, but it is also used to
make pesticides (insect killers), rubber, and_________________.
A. HCl
D. Solvents
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
193. Chlorine is used in drinking water and swimming pool water to kill harmful bacteria. It is
also as used as part of the sanitation process for________________.
A. HCl
D. Chlorine gas
B. HOCl
E. Industrial waste and sewage
C. Chlorine liquid
F. None of the Above
194. _______________can release chlorine gas if it is mixed with certain other cleaning
agents.
A. HCl
D. Chlorine gas
B. HOCl
E. Household chlorine bleach
C. Chlorine liquid
F. None of the Above
39
Chlorination 303 8/9/2015 Assignment
How People can be exposed to Chlorine
195. People’s risk for exposure depends on how close they are to the place where the
___________was released.
A. HCl
D. Chlorine
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
196. If ______________is released into the air, people may be exposed through skin contact or
eye contact. They also may be exposed by breathing air that contains chlorine.
A. Chlorine gas
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms
E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
197. If ____________ is released into water, people may be exposed by touching or drinking
water that contains chlorine.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
198. If ___________ comes into contact with food, people may be exposed by eating the
contaminated food.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
190. ______________ is heavier than air, so it would settle in low-lying areas.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. High chlorine concentrations
F. None of the Above
How Chlorine Works
191. The extent of poisoning caused by ___________depends on the amount of chlorine a
person is exposed to, how the person was exposed, and the length of time of the exposure.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
192. When ______________ gas comes into contact with moist tissues such as the eyes,
throat, and lungs, an acid is produced that can damage these tissues.
A. HCl
D. Chlorine
B. HOCl
E. The hypochlorite ion (OCl-)
C. Chlorine liquid
F. None of the Above
What the Long-Term Health Effects are
193. Long-term complications may occur after breathing in high concentrations of chlorine.
Complications are more likely to be seen in people who develop severe health problems such
as fluid in the lungs (pulmonary edema) following________________.
A. Exposure to chlorine
D. And get medical care as quickly as possible
B. Odor thresholds
E. Moisture, steam, and water
C. The initial exposure
F. None of the Above
40
Chlorination 303 8/9/2015 Assignment
How People can Protect Themselves, and What they Should do if they are
Exposed to Chlorine
194. Leave the area where the chlorine was released and get to fresh air. Quickly moving to an
area where fresh air is available is highly effective in__________________.
A. Reducing exposure to chlorine D. Get medical care as quickly as possible
B. Odor thresholds
E. Moisture, steam, and water
C. A corrosive material
F. None of the Above
195. If the _____________was outdoors, move away from the area where the chlorine was
released. Go to the highest ground possible, because chlorine is heavier than air and will sink to
low-lying areas. If the chlorine release was indoors, get out of the building.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Oxomonosilane
E. Chlorine release
C. Chlorine in solution
F. None of the Above
196. If you think you may have been exposed, remove your clothing, rapidly wash your entire
body with soap and water, __________________.
A. Exposure to chlorine
D. And get medical care as quickly as possible
B. Odor thresholds
E. Moisture, steam, and water
C. A corrosive material
F. None of the Above
How Chlorine Exposure is Treated
197. No antidote exists for____________________. Treatment consists of removing the
chlorine from the body as soon as possible and providing supportive medical care such as
inhaled breathing treatments for wheezing in a hospital setting.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Chlorine exposure
E. Chlorine release
C. Chlorine in solution
F. None of the Above
Chlorine’s Appearance and Odor (QA/QC)
198. ___________ is a greenish-yellow gas with a characteristic pungent odor. It condenses to
an amber liquid at approximately -34 degrees C (-29.2 degrees F) or at high pressures.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Oxomonosilane
E. Chlorine
C. Chlorine in solution
F. None of the Above
199. Odor thresholds ranging from 0.08 to part per million (ppm) parts of air have been
reported. Prolonged exposures may result in______________________.
A. Exposure to chlorine
D. Olfactory fatigue
B. Odor thresholds
E. Moisture, steam, and water
C. A corrosive material
F. None of the Above
Reactivity
200. Conditions Contributing to Instability: Cylinders of chlorine may burst when exposed to
elevated temperatures. Chlorine in solution forms______________.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Oxomonosilane
E. A corrosive material
C. Chlorine in solution
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
201. Incompatibilities: Flammable gases and vapors form explosive mixtures with chlorine.
Contact between chlorine and many combustible substances (such as gasoline and petroleum
products, hydrocarbons, turpentine, alcohols, acetylene, hydrogen, ammonia, and sulfur),
reducing agents, and finely divided metals may cause___________________ .
A. Exposure to chlorine
D. Fires and explosions
B. Odor thresholds
E. Moisture, steam, and water
C. A corrosive material
F. None of the Above
202. Contact between chlorine and arsenic, bismuth, boron, calcium, activated carbon, carbon
disulfide, glycerol, hydrazine, iodine, methane, oxomonosilane, ________________, propylene,
and silicon should be avoided.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Potassium
E. Chlorine release
C. Chlorine in solution
F. None of the Above
203. Chlorine reacts with hydrogen sulfide and water to form____________, and it reacts with
carbon monoxide and sulfur dioxide to form phosgene and sulfuryl chloride.
A. Hydrogen sulfide
D. A characteristic pungent odor
B. Oxomonosilane
E. Hydrochloric acid
C. Chlorine in solution
F. None of the Above
204. Chlorine is also incompatible with ____________________.
A. Exposure to chlorine
D. Hydrogen sulfide
B. Odor thresholds
E. Moisture, steam, and water
C. A corrosive material
F. None of the Above
Disinfection Essentials
205. Selecting the right ______________requires understanding the factors governing the
particular site and the water or wastewater to be treated. In general, the selection of an
appropriate disinfection system should be evaluated against the following six criteria…
A. Operating costs
D. Breathing apparatus and protective clothing
B. Disinfection weapon
E. Net-positive environmental benefit
C. UV has safeguards
F. None of the Above
206. Safety. How does the disinfectant work and what types of precautions are needed to
transport, store, use, and operate the disinfectant system and associated chemicals? If a
system will require significant safety protection—such as use of breathing apparatus and
protective clothing—as well as high levels of operator training, it may be advisable to explore
other,_____________. In addition, while the disinfectant may be relatively safe to use,
consideration also has to be made for the effects of both intentional and unintentional releases
to the environment.
A. Operating costs
D. Breathing apparatus and protective clothing
B. Less intensive systems E. Net-positive environmental benefit
C. UV has safeguards
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
207. Effectiveness. How effective is the disinfectant against the pathogens present in the
water or wastewater? Since the intent is to reduce the levels of pathogens to acceptable
standards, understanding how effective the proposed disinfectant system is in achieving
those_____________, as well as the system's ability to reliably achieve the result, will be
important to selecting the right system.
A. Target levels
D. Net-positive environmental benefit
B. Narrow tolerance
E. Acceptable standards
C. Desired parameters
F. None of the Above
208. Cost. What are the costs associated with the disinfection system, both in terms of
_____________and ongoing operations and maintenance? Operating costs can vary in terms of
the time it takes to service the disinfectant system regularly, and the costs of supplies and
components.
A. Operating costs D. Breathing apparatus and protective clothing
B. Capital outlay
E. Net-positive environmental benefit
C. UV
F. None of the Above
209. Complexity of use. How does the system operate and does it take specialized training to
keep the system within tolerances? Since the outflow from the treatment facility may be subject
to various standards and regulations, if the system is too complex it may require additional staff
time to ensure that it operates within the _______________.
A. Disinfectant system
D. Net-positive environmental benefit
B. Narrow tolerance
E. Acceptable standards
C. Desired parameters
F. None of the Above
210. Environmental/Adverse Effects. What are some of the potential downsides to the
operation of the system as it relates to the distribution system or watershed in which the treated
effluent is discharged? While some systems may provide a net-positive environmental benefit
through increased ________________, other systems may need to have additional treatment of
the disinfected effluent in order to render it benign when released.
A. Operating costs
D. Breathing apparatus and protective clothing
B. Other than chlorine
E. Oxygenation of the receiving waters
C. Safeguards
F. None of the Above
211. Flow and Water Characteristics. Can the system handle fluctuations within the flow or
with changing characteristics of the water or wastewater being processed? If a system has a
narrow tolerance for the amount of water or wastewater flow, this could impact the effectiveness
of the overall system. In addition, if the system cannot adjust for ____________such as dry or
wet weather flow rates of the receiving water body, this may also affect the system's
appropriateness for your application.
A. Off-site concerns
D. Net-positive environmental benefit
B. Narrow tolerance
E. Acceptable standards
C. Desired parameters
F. None of the Above
212. With those criteria in mind, there are primarily four basic disinfection systems currently
available—chlorination, ozone gas, ultraviolet radiation, and______________.
A. Operating costs
D. Chemical treatment other than chlorine
B. Other than chlorine
E. Net-positive environmental benefit
C. UV has safeguards
F. None of the Above
43
Chlorination 303 8/9/2015 Assignment
213. A variety of factors come into play in deciding which type of disinfectant system is right for
your operation. The decision to install a system could be the result of local concerns and
potential to mitigate health risks, as well as_____________. In any event, the operator of an
onsite water or wastewater treatment plant needs to consider some of the safeguards that need
to be in place as well.
A. Improved community relations
D. Net-positive environmental benefit
B. Narrow tolerance
E. Acceptable standards
C. Desired parameters
F. None of the Above
214. "Typical safeguards include operator training and instrumentation monitoring that will
perform a shutdown function if something goes above a certain level," says Schilling. "If they
detect [for example] an ozone leak, you can do an interconnect and do a plant shutdown. UV
has safeguards where you have monitors that tell you what your ________________ is, and if
you're over or under your dosage it will perform some kind of warning of whatever you want to
do."
A. Operating costs
D. Dosage
B. Other than chlorine
E. Net-positive environmental benefit
C. UV has safeguards
F. None of the Above
What Happens to Chlorine When it Enters the Environment?
224. When released to air, chlorine will react with water to form hypochlorous acid and
hydrochloric acid, which are removed from the atmosphere by__________________.
A. Generation of free oxygen radicals
D. Manganese dioxide
B. Chlorine gas
E. Rainfall
C. Hydrochloric acid
F. None of the Above
225. Chlorine is____________. It reacts with water to form hypochlorous acid and hydrochloric
acid. The hypochlorous acid breaks down rapidly. The hydrochloric acid also breaks down; its
breakdown products will lower the pH of the water (makes it more acidic).
A. Free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Slightly soluble in water
E. Basicly hypochlorous and hydrochloric acid
C. Hydrochloric acid
F. None of the Above
226. Since chlorine is a gas it is rarely found in soil. If released to soil, chlorine will react with
moisture forming ______________. These compounds can react with other substances found in
soil.
A. Generation of free oxygen radicals
D. A greenish-yellow, noncombustible gas
B. Chlorine gas
E. Hypochlorous acid and hydrochloric acid
C. Hydrochloric acid
F. None of the Above
227. Chlorine does not accumulate in the____________.
A. Food chain
D. Manganese dioxide
B. Bacteria and viruses
E. Basic building blocks of our planet
C. Salmonella and E. coli
F. None of the Above
44
Chlorination 303 8/9/2015 Assignment
Disinfectant Qualities
228. Restaurants and meat and poultry processing plants rely on chlorine bleach and other
chlorine-based products to kill harmful levels of bacteria such as ___________ on food
preparation surfaces and during food processing.
A. Salmonella and E. coli
D. Studying and synthesizing organic compounds
B. Chlorine disinfection
E. Animals
C. Chemical bridges
F. None of the Above
229. Chlorine is so important in poultry processing that the US Department of Agriculture
requires an almost constant chlorine rinse for much of the cutting equipment. In fact, no proven
economical alternative to chlorine disinfection exists for use in____________________.
A. Salmonella and E. coli
D. Harnessed innovatively for good use
B. Chlorine disinfection
E. Meat and poultry processing facilities
C. Chemical bridging
F. None of the Above
Properties
230. Because it is highly reactive, chlorine is usually found in nature bound with other elements
like sodium, potassium, and magnesium. When chlorine is isolated as___________, chlorine is
a greenish yellow gas, which is 2.5 times heavier than air. It turns to a liquid state at -34°C (29°F), and it becomes a yellowish crystalline solid at -103°C (-153°F).
A. A free oxygen radicals
D. A free element
B. A gas
E. Hypochlorous acid and hydrochloric acid
C. An acid
F. None of the Above
231. Chemists began experimenting with chlorine and _______________in the 18th century.
They learned that chlorine has an extraordinary ability to extend a chemical bridge between
various elements and compounds that would not otherwise react with each other.
A. Salmonella and E. coli
D. Organic compounds
B. Chlorine disinfection
E. Animals
C. Chlorine compounds
F. None of the Above
232. Chlorine has been especially useful in studying and ____________ -- compounds that
have at least one atom of the element carbon in their molecular structure. All living organisms,
including humans, are composed of organic compounds.
A. Synthesizing organic compounds
D. Organic compounds
B. Chlorine disinfection
E. Most abundant chemical elements
C. Chlorine compounds
F. None of the Above
233. Chlorine is one of the _______________ on Earth. It is ubiquitous in soils, minerals, plants
and animals.
A. Synthesizing organic compounds
D. Organic compounds
B. Chlorine disinfection
E. Most abundant chemical elements
C. Chlorine compounds
F. None of the Above
234. Seawater is a huge reservoir of ___________________from the continents and
transported to the oceans by Earth's rivers.
A. Workhorse chemical
D. Useful chemical elements
B. Chlorine-based disinfectants
E. Dissolved chlorine weathered
C. Ancient seawater
F. None of the Above
45
Chlorination 303 8/9/2015 Assignment
235. Chlorine is also one of the most useful chemical elements. Each chemical element has its
own set of unique properties and chlorine is known as _____________--so reactive, in fact, that
it is usually found combined with other elements in the form of compounds. More than 3,500
naturally occurring chlorinated organic (associated with living organisms) compounds alone
have been identified.
A. Synthesizing organic compounds
D. Organic compounds
B. A very reactive element
E. Most abundant chemical elements
C. Chlorine compounds
F. None of the Above
236. Chlorine's ________________have been harnessed innovatively for good use. For
example, this element plays a huge role in public health.
A. Synthesizing organic compounds
D. Organic compounds
B. A very reactive element
E. Chemical properties
C. Chlorine compounds
F. None of the Above
237. _______________ are capable of removing a wide variety of disease-causing germs from
drinking water and wastewater as well as from hospital and food production surfaces.
A. Workhorse chemical
D. Useful chemical elements
B. Chlorine-based disinfectants
E. Organic compounds
C. Ancient seawater
F. None of the Above
238. Additionally, chlorine plays an important role in the manufacture of thousands of products
we depend upon every day, including such diverse items as cars, computers, pharmaceuticals
and military flak jackets. As the ninth largest chemical produced in the U.S. by volume, chlorine
is truly a "________ ."
A. Workhorse chemical
D. Useful chemical elements
B. Chlorine-based disinfectants
E. Organic compounds
C. Ancient seawater
F. None of the Above
Released From the Salt of the Earth
239. Chlorine is produced industrially from the compound sodium chloride, one of the many
salts found in geologic deposits formed from the slow evaporation of ______________.
A. Workhorse chemical
D. Useful chemical elements
B. Chlorine-based disinfectants
E. Organic compounds
C. Ancient seawater
F. None of the Above
Chlorine’s Effectiveness
240. The effectiveness of ___________ depends on the chlorine demand of the water, the
concentration of the chlorine solution added, the time that chlorine is in contact with the
organism, and water quality.
A. Chlorine residual D. Chlorination
B. Color change
E. Required contact time
C. Chlorine demand F. None of the Above
241. As the concentration of the chlorine increases, the ________________ to disinfect
decreases.
A. pH increases
D. Required contact time
B. Chlorine level and water quality E. Not available for disinfection
C. Free chlorine residual
F. None of the Above
46
Chlorination 303 8/9/2015 Assignment
242. Chlorination is more effective as______________.
A. Chlorine residual D. Chlorination
B. Color change
E. Water temperature increases
C. Chlorine demand F. None of the Above
243. Chlorination is less effective as the _____________(becomes more alkaline).
A. Water's pH increases
D. Required contact time
B. Chlorine level and water quality E. Is not available for disinfection
C. Free chlorine residual
F. None of the Above
244. Chlorination is less effective in___________.
A. Chlorine residual D. Chlorination
B. Color change
E. Cloudy (turbid) water
C. Chlorine demand F. None of the Above
245. When chlorine is added to the water supply, _____________in water (like iron,
manganese, hydrogen sulfide, and ammonia) and is not available for disinfection.
A. pH increases
D. Required contact time
B. Chlorine level and water quality E. Part of it combines with other chemicals
C. Free chlorine residual
F. None of the Above
246. The amount of chlorine that reacts with the other chemicals plus the amount required to
achieve disinfection is the _____________ of the water.
A. Chlorine residual D. Chlorination
B. Color change
E. Free chlorine residual
C. Chlorine demand F. None of the Above
247. The safest way to be sure that the amount of chlorine added is sufficient is to add a little
more than is required. This will result in ____________that can be measured easily. This
chlorine residual must be maintained for several minutes depending on chlorine level and water
quality.
A. pH increases
D. Required contact time
B. Chlorine level and water quality E. A free chlorine residual
C. Chlorine demand
F. None of the Above
248. Kits are available for measuring the _________ by looking for a color change after the test
chemical is added. The test is simple and easy for a homeowner to perform.
A. Chlorine residual D. Free chlorine residual
B. Color change
E. Required contact time
C. Chlorine demand F. None of the Above
249. If chlorination is required for the water supply, the chlorine residual should be tested
regularly to make sure the system is working properly. The kit should specify that it measures
the free chlorine residual and not the______________.
A. pH increases
D. Required contact time
B. Chlorine level and water quality E. Total chlorine
C. Free chlorine residual
F. None of the Above
(S) Means the answer can be plural or singular
47
Chlorination 303 8/9/2015 Assignment
250. Once chlorine has combined with other chemicals it is not effective as a disinfectant. If a
test kit does not distinguish between free chlorine and __________with other chemicals, the test
may result in an overestimation of the chlorine residual.
A. Chlorine residual D. Chlorination
B. Color change
E. Chlorine combined
C. Chlorine demand F. None of the Above
251. Chlorine will kill bacteria in water, but it takes some time. The time needed depends on the
concentration of chlorine.__________: simple chlorination and superchlorination.
A. pH increases
D. Required contact time
B. Chlorine level and water quality E. Two methods of chlorination are used to disinfect water
C. Free chlorine residual
F. None of the Above
Oxidation Chemistry
252. Oxidation chemistry has long been an accepted and effective part of many water
treatment programs. Oxidizing chemicals used in today's water treatment programs include:
chlorine, chlorine dioxide, bromine, bromine/chlorine releasing compounds, ozone
and_____________.
A. Limit the effects of organic material
D. An additional killing mechanism
B. Hydrogen peroxide
E. Limit the travel of pathogens
C. Residual level of disinfection
F. None of the Above
253. _____________are often found at the forefront of many cooling water treatment programs.
In large volume or once-through cooling systems they are usually the primary biocide and often
are the most cost-effective programs available to a plant.
A. Oxidizing microbiocides
D. The primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. Environmental and regulatory impact
F. None of the Above
254. When selecting these _______________, several factors should be considered before a
technically sound program is implemented.
A. As necessary
D. The primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. Environmental and regulatory impact
F. None of the Above
255. Environmental and regulatory impact, ________, process contamination, and equipment
capital and maintenance expense all play a role in the decision-making process.
A. As necessary
D. The primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. System pH
F. None of the Above
256. The primary killing mechanism these types of microbiocides use is oxidizing protein
groups within a microorganism. Proteins are the basic components of ________that are
necessary for life-sustaining cellular processes such as respiration.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Essential cellular enzymes
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
48
Chlorination 303 8/9/2015 Assignment
257.
The destruction of these proteins deprives the cell of its ability to carry out
______________and quickly kills it. One oxidant is chlorine dioxide, which appears to provide
an additional killing mechanism.
A. Limit the effects of organic material
D. An additional killing mechanism
B. Numerous alternative disinfection processes
E. Fundamental life functions
C. Residual level of disinfection
F. None of the Above
258. Chlorine dioxide is able to diffuse readily through hydrophobic lipid layers of an organism,
allowing it to react with__________, which directly inhibits protein synthesis. Since amino acids
are the basic building blocks of all cellular proteins, destruction of these molecules has a
devastating effect on the microorganism.
A. Cellular amino acids
D. The primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. Environmental and regulatory impact
F. None of the Above
Understanding Disinfection
Wastewater Disinfection
259. There are a number of chemicals and processes that will____________, but none are
universally applicable. Most septic tanks discharge into various types of subsurface wastewater
infiltration systems (SWIS), such as tile fields or leach fields.
A. Limit the effects of organic material
D. Disinfect wastewater
B. Numerous alternative disinfection processes
E. Limit the travel of pathogens
C. Residual level of disinfection
F. None of the Above
260. Aerobic treatment processes reduce pathogens, but not enough to qualify as a _______.
A. As necessary
D. Primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. Environmental and regulatory impact
F. None of the Above
261. Chlorination/dechlorination has been the most widely used disinfection technology in the
U.S.; ozonation and UV light are emerging technologies." Each of these three methods have
different considerations for the________.
A. Disinfection of wastewater
D. The primary methods used for the disinfection
B. Disinfection process
E. Economical and versatile chemicals
C. Environmental and regulatory impact
F. None of the Above
Water Disinfection
262. Disinfection is usually the final stage in the __________in order to limit the effects of
organic material, suspended solids and other contaminants.
A. Limit the effects of organic material
D. Water treatment process
B. Numerous alternative disinfection processes
E. Limit the travel of pathogens
C. Residual level of disinfection
F. None of the Above
263. Like the disinfection of wastewater, the primary methods used for the ________in very
small (25-500 people) and small (501-3,300 people) treatment systems are ozone, ultraviolet
irradiation (UV) and chlorine.
A. Chlorates are powerful oxidizers D. Microbiological contamination
B. Adverse health effects
E. Sodium chloride
C. Disinfection of water
F. None of the Above
49
Chlorination 303 8/9/2015 Assignment
264. There are ____________ that have been less widely used in small and very small water
treatment systems, including chlorine dioxide, potassium permanganate, chloramines and
peroxone (ozone/hydrogen peroxide).
A. Limit the effects of organic material
D. Additional killing mechanism
B. Numerous alternative disinfection processes
E. Pathogens
C. Residual level of disinfection
F. None of the Above
265. Surface waters have been the focal point of ____________since their inception, as
groundwaters (like wells) have been historically considered to be free of microbiological
contamination. Current data indicates this to not be true. Amendments to the Safe Drinking
Water Act in 1996 mandate the development of regulations to require disinfection of
groundwater "as necessary”.
A. Chlorates are powerful oxidizers D. Microbiological contamination
B. Adverse health effects
E. Sodium chloride
C. Water disinfection regulations
F. None of the Above
Residual Disinfection
266. The EPA requires a residual level of disinfection of water in pipelines to prevent microbial
re-growth and help protect treated water throughout the distribution system. ________are 4 mg/l
for chlorine, 4 mg/l for chloramines and 0.8 mg/l for chlorine dioxide.
A. Acid/base balance
D. EPA”s maximum residual disinfection levels (MRDLs)
B. Stable perchlorates
E. Chemical formula CaCl2
C. Formula ClO-3
F. None of the Above
267. Although chlorine levels are usually significantly lower in tap water, EPA believes that
levels as high as the ________________pose no risk of adverse health effects, allowing for an
adequate margin of safety (U.S. EPA, 1998a).
A. MRDLs
D. Microbiological contamination
B. Adverse health effects
E. Sodium chloride
C. The chloride ion
F. None of the Above
Chlorate Ion
268. The chlorate anion has the formula ClO-3. In this case, the chlorine atom is in the +5
oxidation state. "Chlorate" can also refer to chemical compounds containing this anion;
chlorates are the salts of chloric acid. "Chlorate", when followed by a roman numeral in
parentheses, e.g. chlorate (VII), refers to a particular oxyanion of chlorine. As predicted by
VSEPR, chlorate anions have___________.
A. Acid/base balance
D. Trigonal pyramidal structures
B. Stable perchlorates
E. Chemical formula CaCl2
C. Formula ClO-3
F. None of the Above
269. ____________ and should be kept away from organics or easily oxidized materials.
Mixtures of chlorate salts with virtually any combustible material (sugar, sawdust, charcoal,
organic solvents, metals, etc.) will readily deflagrate.
A. Chlorates are powerful oxidizers D. Microbiological contamination
B. Adverse health effects
E. Sodium chloride
C. Formula ClO-3
F. None of the Above
50
Chlorination 303 8/9/2015 Assignment
270. Chlorates were once widely used in _________for this reason, though their use has fallen
due to their instability. Most pyrotechnic applications which formerly used chlorates in the past
now use the more stable perchlorates instead.
A. Acid/base balance
D. Pyrotechnics
B. Stable perchlorates
E. Chemical formula CaCl2
C. Formula ClO-3
F. None of the Above
Chloride Ion
271. The chloride ion is formed when the_________, a halogen, gains an electron to form an
anion (negatively-charged ion) Cl-.
A. Chlorates are powerful oxidizers D. Microbiological contamination
B. Adverse health effects
E. Sodium chloride
C. Element chlorine
F. None of the Above
272. The salts of hydrochloric acid contain chloride ions and can also be called chlorides. The
chloride ion, and its salts such as sodium chloride,_______________.
A. Acid/base balance
D. Are very soluble in water
B. The stable perchlorates E. The chemical formula CaCl2
C. The formula ClO-3
F. None of the Above
273. The word chloride can also form part of the name of chemical compounds in which one or
more chlorine atoms are covalently bonded. For example, methyl chloride, more commonly
called chloromethane, (CH3Cl) is___________, which does not contain a chloride ion.
A. Chlorates are powerful oxidizers D. An organic covalently bonded compound
B. Adverse health effects
E. Sodium chloride
C. The chloride ion
F. None of the Above
274. Chloride is used to form salts that can preserve food such as sodium chloride. Other salts
such as calcium chloride, magnesium chloride, potassium chloride have varied uses ranging
from medical treatments to________________.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Cement formation
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
275. An example is table salt, which is sodium chloride with the chemical formula______. In
water, it dissociates into Na+ and Cl- ions.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. NaCl
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
276. ___________is also the prosthetic group present in the amylase enzyme. Another
example is calcium chloride with the chemical formula CaCl2.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. A chloride ion
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
51
Chlorination 303 8/9/2015 Assignment
277. Calcium chloride is a salt that is marketed in pellet form for removing dampness from
rooms. ____________ is also used for maintaining unpaved roads and for sanite fortifying
roadbases for new construction. In addition, Calcium chloride is widely used as a deicer since it
is effective in lowering the melting point when applied to ice.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Calcium chloride
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
278. In the petroleum industry, the ___________are a closely monitored constituent of the mud
system. An increase of the chlorides in the mud system may be an indication of drilling into a
high-pressure saltwater formation. Its increase can also indicate the poor quality of a target
sand.
A. Chemical formula CaCl2 D. Chlorides
B. Chloride
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
279. ______________ is also a useful and reliable chemical indicator of river / groundwater
fecal contamination, as chloride is a non-reactive solute and ubiquitous to sewage & potable
water. Many water regulating companies around the world utilize chloride to check the
contamination levels of the rivers and potable water sources.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Chloride
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
Chlorite Ion
280. The chlorite ion is__________. A chlorite (compound) is a compound that contains this
group, with chlorine in oxidation state +3. Chlorites are also known as salts of chlorous acid.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Chloride
E. Chlorine dioxide
C. ClO2F. None of the Above
281. Chlorine can assume oxidation states of -1, +1, +3, +5, or +7 within the corresponding
anions Cl-, ClO-, ClO2-, ClO3-, or ClO4-, known commonly and respectively as__________ .
A. Chemical formula CaCl2 D. Chloride, hypochlorite, chlorite, chlorate, and perchlorate
B. Chloride
E. Chlorine dioxide
C. Chlorite ion is ClO2-.
F. None of the Above
282. An additional oxidation state of +4 is seen in the neutral compound_________, which has
a similar structure to chlorite ClO2- (oxidation state +3) and the cation chloryl (ClO2+) (oxidation
state +5).
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Chloride
E. Chlorine dioxide ClO2
C. Chlorite ion is ClO2-.
F. None of the Above
52
Chlorination 303 8/9/2015 Assignment
Chlorine Dioxide
283. Chlorine dioxide is a chemical compound with the formula _________. This yellowishgreen gas crystallizes as bright orange crystals at -59 °C. As one of several oxides of chlorine, it
is a potent and useful oxidizing agent used in water treatment and in bleaching.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Chloride
E. ClO2
C. Chlorite ion is ClO2-.
F. None of the Above
284. The molecule _________ has an odd number of valence electrons and it is therefore a
paramagnetic radical. Its electronic structure has long baffled chemists because none of the
possible Lewis structures are very satisfactory. In 1933 L.O. Brockway proposed a structure that
involved a three-electron bond.
A. Chemical formula CaCl2 D. Corresponding anions Cl-, ClO-, ClO2-, ClO3-, or ClO4
B. Chloride
E. ClO2
C. Chlorite ion is ClO2-.
F. None of the Above
285. Chemist Linus Pauling further developed this idea and arrived at two resonance structures
involving a double bond on one side and a single bond plus three-electron bond on the other. In
Pauling's view the latter combination should represent a bond that is slightly weaker than the
double bond. In molecular orbital theory this idea is commonplace if the third electron is placed
in
an
anti-bonding
orbital.
Later
work
has
confirmed
that
the
HOMO
is_____________________.
A. An anti-bonding orbital
D. A common undesirable by-product
B. A single halogen
E. Indeed an incompletely-filled orbital
C. Hypochlorite compounds F. None of the Above
286. ______________ is a highly endothermic compound that can decompose extremely
violently when separated from diluting substances. As a result, preparation methods that involve
producing solutions of it without going through a gas phase stage are often preferred. Arranging
handling in a safe manner is essential.
A. High-test calcium hypochlorite(s) D. Negative charge of the conjugate base
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
Haloacetic Acids
287. Haloacetic acids are ____________________in which a halogen atom takes the place of
a hydrogen atom in acetic acid. Thus, in a monohaloacetic acid, a single halogen would replace
a hydrogen atom. For example, chloroacetic acid would have the structural formula CH2ClCO2H.
A. An anti-bonding orbital
D. Carboxylic acids
B. A single halogen
E. Calcium hypochlorite
C. Hypochlorite compounds F. None of the Above
288. In the same manner, in dichloroacetic acid two chlorine atoms would take the place of two
hydrogen atoms (CHCl2CO2H). The inductive effect caused by the _____________often result
in the higher acidity of these compounds by stabilizing the negative charge of the conjugate
base.
A. High-test calcium hypochlorite(s) D. Electronegative halogens
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
53
Chlorination 303 8/9/2015 Assignment
Contaminants in Drinking Water
289. Haloacetic acids (HAAs) are a common undesirable by-product of drinking water
chlorination. Exposure to such ________________in drinking water has been associated with a
number of health outcomes by epidemiological studies, although the putative agent in such
studies has not been identified.
A. An anti-bonding orbital
D. Disinfection by-products
B. A single halogen
E. Calcium hypochlorite
C. Hypochlorite compounds F. None of the Above
Hypochlorites
290. Hypochlorites are calcium or sodium salts of hypochlorous acid and are supplied either dry
or in liquid form (as, for instance, in commercial bleach). The same residuals are obtained as
with gas chlorine, but the effect on the ____________of the treated water is different.
A. High-test calcium hypochlorite(s) D. Negative charge
B. Calcium hypochlorite tablets
E. pH
C. Hypochlorous acid
F. None of the Above
291. Hypochlorite compounds contain an excess of ________and tend to raise the pH of the
water.
A. An anti-bonding orbital
D. A common undesirable by-product
B. Alkali
E. Calcium hypochlorite
C. Hypochlorite compounds F. None of the Above
292. Calcium hypochlorite tablets are the predominant form in use in the United States for
swimming pools. _______________is the only liquid hypochlorite disinfectant in current use.
There are several grades and proprietary forms available.
A. High-test calcium hypochlorite(s)
D. Sodium hypochlorite
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
293. Pound-for-pound of available chlorine, ______________have oxidizing powers equal to
gas chlorine and can be employed for the same purposes in water treatment.
A. Hypochlorite compounds D. And some undesirable by-product of drinking water
B. And some acids
E. With calcium hypochlorite
C. Hypochlorous compounds
F. None of the Above
294. Gas chlorination requires a larger initial investment for feed equipment than what is
needed for ____________.
A. High-test calcium hypochlorite(s) D. Negative charge of the conjugate base
B. Calcium hypochlorite tablets
E. Hypochlorite compounds
C. Hypochlorous acid
F. None of the Above
295. Calcium hypochlorite materials used in the water industry are chemically different from
those materials variously marketed for many years as bleaching powder, chloride of lime, or
chlorinated lime. Materials now in common use are ________containing about 70 percent
available chlorine and marketed under several trade names.
A. An anti-bonding orbital
D. High-test calcium hypochlorites
B. A single halogen
E. Calcium hypochlorite
C. Hypochlorite compounds F. None of the Above
(S) Means the answer can be plural or singular
54
Chlorination 303 8/9/2015 Assignment
296. _______________ are white corrosive solids that give off a strong chlorine odor. Granular
powdered or tablet forms are commercially available and all are readily soluble in water.
A. High-test calcium hypochlorite(s)
D. Negative charge of the conjugate base
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
297. __________________is sold only as a liquid and is normally referred to as liquid bleach. It
is generally available in concentrations of 5 to 15 percent available chlorine. These solutions are
clear, light yellow, strongly alkaline, and corrosive in addition to having a strong chlorine smell.
A. Sodium hypochlorite
D. High-test calcium hypochlorites
B. A single halogen
E. Calcium hypochlorite
C. Hypochlorite compounds
F. None of the Above
298. _____________, though highly active, are relatively stable throughout production,
packaging, distribution, and storage. Storage at 86° F. for a year may reduce the available
chlorine by about 10 percent. Storing at lower temperatures reduces the loss.
A. High-test calcium hypochlorite(s)
D. Negative charge of the conjugate base
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
299. ________________solutions are unstable to some degree and deteriorate more rapidly
than the dry compounds. Most producers recommend a shelf life of 60 to 90 days. Because light
and heat accelerate decomposition, containers should be stored in a dry, cool, and dark area.
A. High-test calcium hypochlorite(s) D. All sodium-hypochlorite
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
Disinfection Byproducts
300. ________________ are formed when disinfectants used in water treatment plants react
with bromide and/or natural organic matter (i.e., decaying vegetation) present in the source
water. Different disinfectants produce different types or amounts of disinfection byproducts.
A. Disinfection byproducts
D. Occurring organic and inorganic matter in water
B. Other disinfectants
E. Most prevalent THM
C. Naturally occurring bromide
F. None of the Above
301. _________________for which regulations have been established have been identified in
drinking water, including trihalomethanes, haloacetic acids, bromate, and chlorite.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. HAA5
E. Disinfection byproducts
C. Trihalomethanes F. None of the Above
Trihalomethanes (THM)
302. _______________are a group of four chemicals that are formed along with other
disinfection byproducts when chlorine or other disinfectants used to control microbial
contaminants in drinking water react with naturally occurring organic and inorganic matter in
water.
A. Disinfection byproducts
D. Occurring organic and inorganic matter in water
B. Other disinfectants
E. Trihalomethanes (THM)
C. Naturally occurring bromide
F. None of the Above
55
Chlorination 303 8/9/2015 Assignment
303. The _____________ are chloroform, bromodichloromethane, dibromochloromethane, and
bromoform. EPA has published the Stage 1 Disinfectants/Disinfection Byproducts Rule to
regulate total trihalomethanes (TTHM) at a maximum allowable annual average level of 80 parts
per billion.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. HAA5
E. Chloroform
C. Trihalomethanes F. None of the Above
Haloacetic Acids (HAA5)
304. Haloacetic Acids (HAA5) are a group of chemicals that are formed along with other
disinfection byproducts when chlorine or other disinfectants used to control _________in
drinking water react with naturally occurring organic and inorganic matter in water.
A. Disinfection byproducts
D. Occurring organic and inorganic matter in water
B. Other disinfectants
E. Microbial contaminants
C. Naturally occurring bromide
F. None of the Above
305. The regulated haloacetic acids, known as _______________, are: monochloroacetic acid,
dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid. EPA
has published the Stage 1 Disinfectants/Disinfection Byproducts Rule to regulate HAA5 at 60
parts per billion annual average.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. HAA5
E. Chloroform
C. Trihalomethanes F. None of the Above
306. Bromate is a chemical that is formed when ___________used to disinfect drinking water
reacts with naturally occurring bromide found in source water. EPA has established the Stage 1
Disinfectants/Disinfection Byproducts Rule to regulate bromate at annual average of 10 parts
per billion in drinking water. This standard will become effective for large public water systems
by December 2001 and for small surface water and all ground public water systems in
December 2003.
A. Disinfection byproducts
D. Occurring organic and inorganic matter in water
B. Other disinfectants
E. Ozone
C. Naturally occurring bromide
F. None of the Above
Chlorite
307. _______________is a byproduct formed when chlorine dioxide is used to disinfect water.
EPA has published the Stage 1 Disinfectants/Disinfection Byproducts Rule to regulate chlorite at
a monthly average level of 1 part per million in drinking water.
A. Chlorite
D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. HAA5
E. Chloroform
C. Trihalomethanes F. None of the Above
Chloroform
308. Chloroform, typically the most prevalent ________ measured in chlorinated water, is
probably the most thoroughly studied disinfection byproduct. Toxicological studies have shown
that high levels of chloroform can cause cancer in laboratory animals.
A. Disinfection byproducts
D. Occurring organic and inorganic matter in water
B. Other disinfectants
E. THM
C. Naturally occurring bromide
F. None of the Above
56
Chlorination 303 8/9/2015 Assignment
309. Extensive research conducted since the early 1990s provides a clearer picture of what this
means for humans exposed to far lower levels through drinking water. One study (Larson et al.
1994a) conducted by the Centers for Health Research (CIIT) observed that a very large dose of
_______, when given to mice once per day into the stomach (a procedure known as gavage),
produced liver damage and eventually cancer. In a second CIIT cancer study (Larson et al.,
1994b), mice were given the same daily dose of chloroform through the animals’ drinking water.
This time, no cancer was produced.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. HAA5
E. Chloroform
C. Trihalomethanes F. None of the Above
310. In its most recent risk assessment, EPA considered the wealth of available information on
chloroform, including the important work done at CIIT. EPA concludes that exposure to
chloroform below the threshold level that causes cell damage is unlikely to increase the risk of
cancer. While __________is likely to be carcinogenic at a high enough dose, exposures below
a certain dose range are unlikely to pose any cancer risk to humans (US EPA, 2002a). For
drinking water meeting EPA standards, chloroform is unlikely to be a health concern.
A. Disinfection byproducts D. Chloroform
B. Other disinfectants
E. Most prevalent THM
C. Naturally occurring bromide
F. None of the Above
Sodium Chlorate
311. Sodium chlorate is a chemical compound with the chemical formula (NaClO3). When pure,
it is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes
above 250 °C to release oxygen and leave______________. Industrially, sodium chlorate is
synthesized from the electrolysis of a hot sodium chloride solution in a mixed electrode tank.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Sodium chloride
C. Phosphorus
F. None of the Above
312. It can also be synthesized by passing ______into a hot sodium hydroxide solution. It is
then purified by crystallization.
A. Chlorate
D. Sodium metaborate or ammonium phosphates
B. Oxygen
E. The free acid, chlorous acid, HClO2
C. Chlorine gas
F. None of the Above
Chemical Oxygen Generation
313. Chemical oxygen generators, such as those in commercial aircraft, provide emergency
oxygen to passengers to protect them from drops in cabin pressure by catalytic decomposition
of ___________. The catalyst is normally iron powder.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Sodium chlorate
C. Phosphorus
F. None of the Above
(S) Means the answer can be plural or singular
57
Chlorination 303 8/9/2015 Assignment
314. ____________is used to absorb the chlorine which is a minor product in the
decomposition. Iron powder is mixed with sodium chlorate and ignited by a charge which is
activated by pulling on the emergency mask. The reaction produces more oxygen than is
required for combustion. Similarly, the Solidox welding system used pellets of sodium chlorate
mixed with combustible fibers to generate oxygen.
A. Chlorate
D. Sodium metaborate or ammonium phosphates
B. Oxygen
E. Barium peroxide (BaO2)
C. Hot sodium hydroxide solution F. None of the Above
Toxicity in Humans
315. Due to its oxidative nature, sodium chlorate can be very toxic if ingested. The oxidative
effect on hemoglobin leads to methaemoglobin formation, which is followed by denaturation of
the globin protein and a cross-linking of ___________with resultant damage to the membrane
enzymes.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Erythrocyte membrane proteins
C. Phosphorus
F. None of the Above
316. This leads to increased permeability of the membrane, and severe hemolysis. The
denaturation of hemoglobin overwhelms the capacity of the G6PD metabolic pathway. In
addition, this enzyme is directly denatured by ___________ reducing its activity.
A. Chlorate
D. Sodium metaborate or ammonium phosphates
B. Oxygen
E. The free acid, chlorous acid, HClO2
C. Hot sodium hydroxide solution F. None of the Above
317. Therapy with ____________ and methylene blue are frequently used in the treatment of
methemoglobinemia. However, since methylene blue requires the presence of NADPH that
requires normal functioning of G6PD system, it is less effective than in other conditions
characterized by hemoglobin oxidation.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
Formulations
318. Sodium chlorate comes in dust, spray and granule formulations. There is a risk of fire and
explosion in dry mixtures with other substances, especially organic materials, and__________,
sulfur, phosphorus, powdered metals, strong acids. In particular, when mixed with sugar, it has
explosive properties.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Other herbicides
C. Phosphorus
F. None of the Above
319. If accidentally mixed with one of these substances it should not be stored in human
dwellings. Marketed formulations contain a fire retardant, but this has little effect if deliberately
ignited. Most commercially available chlorate weedkillers contain approximately
__________with the balance being a fire depressant such as sodium metaborate or ammonium
phosphates.
A. Chlorate
D. 53% sodium chlorate
B. Oxygen
E. The free acid, chlorous acid, HClO2
C. Hot sodium hydroxide solution F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Sodium Chlorite
320. Sodium chlorite, like many oxidizing agents, should be protected from inadvertent
contamination by organic materials to avoid the formation of________. The chemical explodes
on percussive impact, and will ignite if combined with a strong reducing agent.
A. Sodium chlorate D. An explosive mixture
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
Toxicity
321. _____________is a strong oxidant and can therefore be expected to cause clinical
symptoms similar to the well-known sodium chlorate: methemoglobinemia, hemolysis, renal
failure.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Sodium chlorite
C. Phosphorus
F. None of the Above
322. A dose of 10-15 grams of _________ can be lethal. Methemoglobemia had been
demonstrated in rats and cats, and recent studies by the EMEA have confirmed that the clinical
symptomatology is very similar to the one caused by sodium chlorate in the rat, mouse, rabbit,
and the green monkey.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
323. There is only one human case in the medical literature of____________. It seems to
confirm that the toxicity is equal to sodium chlorate.
A. Sodium chlorate D. Chlorite poisoning
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
324. From the analogy with ________, even small amounts of about 1 gram can be expected to
cause nausea, vomiting and even life-threatening hemolysis in Glucose-6-Phosphate
Dehydrogenase deficient persons.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
Manufacture
325. The free acid, chlorous acid, HClO2, is only stable at low concentrations. Since it cannot
be concentrated, it is not a commercial product. However, the corresponding sodium salt,
sodium chlorite, _____________is stable and inexpensive enough to be commercially available.
A. Chlorate
D. Sodium metaborate or ammonium phosphates
B. Oxygen
E. NaClO2
C. Hot sodium hydroxide solution F. None of the Above
326. The corresponding salts of heavy metals (Ag+, Hg+, Tl+, Pb2+, and also Cu2+ and NH4+)
decompose explosively with heat or shock. Sodium chlorite is derived indirectly from_________.
A. Chlorate
D. Sodium metaborate or ammonium phosphates
B. Oxygen
E. The free acid, chlorous acid, HClO2
C. Sodium chlorate, NaClO3
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
327. First, the explosive (only at concentrations greater than 10% in atmosphere) ______is
produced by reducing sodium chlorate in a strong acid solution with a suitable reducing agent
(for example, sodium sulfite, sulfur dioxide, or hydrochloric acid).
A. Sodium chlorate D. Chlorine dioxide, ClO2
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
328. The chlorine dioxide is then absorbed into an alkaline solution and reduced with hydrogen
peroxide (H2O2), yielding____________________.
A. Sodium chlorate D. Electrolysis of a hot sodium chloride solution
B. Ascorbic acid
E. Catalytic decomposition of sodium chlorate
C. Phosphorus
F. None of the Above
Stachybotrys
329. Stachybotrys is a genus of molds, or asexually-reproducing, filamentous fungi. Closely
related to the genus Memnoniella, most Stachybotrys species inhabit materials rich in cellulose.
The genus has a widespread distribution, and contains about 50 species. The most infamous
species, S. chartarum (also known as S. atra) and S. chlorohalonata are known as
_____________in the U.S. and are frequently associated with poor indoor air quality that arises
after fungal growth on water-damaged building materials
A. Salmonella and E. coli
D. Organic compounds
B. Mycotoxins
E. Stachybotrys
C. "Black mold" or "toxic black mold"
F. None of the Above
Symptoms of Stachybotrys Exposure in Humans
330. Exposure to the mycotoxins present in Stachybotrys chartarum or ________ atra can have
a wide range of effects.
A. Salmonella and E. coli
D. Organic compounds
B. Mycotoxins
E. Stachybotrys
C. Exposure and volume of spores F. None of the Above
331. Depending on the length of exposure and volume of _________inhaled or ingested,
symptoms can manifest as chronic fatigue or headaches, fever, irritation to the eyes, mucous
membranes of the mouth, nose and throat, sneezing, rashes, and chronic coughing. In severe
cases of exposure or cases exacerbated by allergic reaction, symptoms can be extreme
including nausea, vomiting, and bleeding in the lungs and nose.
A. Salmonella and E. coli
D. Organic compounds
B. Mycotoxins
E. Stachybotrys
C. Spores
F. None of the Above
Understanding Commonly Used Water Disinfectants
332. Almost all U.S. systems that disinfect their water use some type of chlorine-based
process, either alone or in combination with _______________.
A. Other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Eliminates slime bacteria
C. Removes chemical compounds
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
333. In addition to controlling disease-causing organisms, chlorination offers a number of
benefits including:….
Reduces many_______________________;
A. Combination with other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Disagreeable tastes and odors
C. Removes chemical compounds
F. None of the Above
334. Eliminates _______________that commonly grow in water supply reservoirs, on the walls
of water mains and in storage tanks;
A. Combination with other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Slime bacteria, molds and algae
C. Removes chemical compounds
F. None of the Above
335. Removes chemical compounds that have unpleasant tastes and______________; and….
A. Combination with other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Hinder disinfection
C. Removes chemical compounds
F. None of the Above
336. Helps remove _______________ from raw water.
A. Combination with other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Eliminates slime bacteria
C. Iron and manganese
F. None of the Above
337. As importantly, only chlorine-based chemicals provide “_____________” levels that
prevent microbial re-growth and help protect treated water throughout the distribution system.
A. Combination with other disinfectants
D. Disease-causing organisms
B. Residual disinfectant
E. Eliminates slime bacteria
C. Removes chemical compounds
F. None of the Above
The Risks of Waterborne Disease
338. Where adequate water treatment is not readily available, the impact on public health can
be devastating. Worldwide, about 1.2 billion people lack access to safe drinking water, and
twice that many lack adequate sanitation. As a result, the World Health Organization estimates
that 3.4 million people, mostly children, die every year from______________________.
A. Total Coliform (TC)
D. Cryptosporidium
B. Water-related diseases
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
339. Even where water treatment is widely practiced, constant vigilance is required to guard
against waterborne disease outbreaks. Well-known pathogens such as ________ are easily
controlled with chlorination, but can cause deadly outbreaks given conditions of inadequate or
no disinfection. A striking example occurred in May 2000 in the Canadian town of Walkerton,
Ontario.
A. Total Coliform (TC)
D. Cryptosporidium
B. E. coli
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
340. Seven people died and more than 2,300 became ill after ________and other bacteria
infected the town’s water supply. A report published by the Ontario Ministry of the Attorney
General concludes that, even after the well was contaminated, the Walkerton disaster could
have been prevented if the required chlorine residuals had been maintained.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. E. coli
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
341. Some emerging pathogens such as Cryptosporidium are resistant to chlorination and can
appear even in high quality water supplies. __________ was the cause of the largest reported
drinking water outbreak in U.S. history, affecting over 400,000 people in Milwaukee in April
1993. More than 100 deaths are attributed to this outbreak.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
342. New regulations from the U.S. Environmental Protection Agency (EPA) will require water
systems to monitor __________ and adopt a range of treatment options based on source water
Cryptosporidium concentrations. Most water systems are expected to meet EPA requirements
while continuing to use chlorination.
A. Total Coliform (TC)
D. Cryptosporidium
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
The Benefits of Chlorine
Potent Germicide
343. Chlorine disinfectants can reduce the level
immeasurable levels.
A. Cryptosporidium parvum and Giardia lamblia
B. Many disease-causing microorganisms
C. Nitrogenous compounds
of ___________ in drinking water to almost
D. Sodium hypochlorite solution
E. Chlorine disinfectants
F. None of the Above
344. Chlorine is added to drinking water to destroy pathogenic (disease-causing) organisms. It
can be applied in several forms:______________, sodium hypochlorite solution (bleach) and
dry calcium hypochlorite.
A. Cryptosporidium parvum and Giardia lamblia
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms
E. Chlorine disinfectants
C. Elemental chlorine (chlorine gas)
F. None of the Above
345. When applied to water, each of these forms “free chlorine” (see Sidebar: How Chlorine
Kills Pathogens). One pound of elemental chlorine provides approximately as much
_________as one gallon of sodium hypochlorite (12.5% solution) or approximately 1.5 pounds
of calcium hypochlorite (65% strength).
A. Free available chlorine
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
346. While any of these forms of chlorine can effectively disinfect drinking water, each has
distinct advantages and limitations for_______________. Almost all water systems that disinfect
their water use some type of chlorine-based process, either alone or in combination with other
disinfectants.
A. Cryptosporidium parvum and Giardia lamblia
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms
E. Chlorine disinfectants
C. Particular applications
F. None of the Above
Taste and Odor Control
347. Chlorine disinfectants reduce many disagreeable tastes and odors. Chlorine oxidizes
many naturally occurring substances such as____________, sulfides and odors from decaying
vegetation.
A. Cryptosporidium parvum and Giardia lamblia
D. Sodium hypochlorite solution
B. Many disease-causing microorganisms
E. Foul-smelling algae secretions
C. Nitrogenous compounds
F. None of the Above
Biological Growth Control
348. Chlorine disinfectants eliminate __________that commonly grow in water supply
reservoirs, on the walls of water mains and in storage tanks.
A. Cryptosporidium parvum and Giardia lamblia
D. Slime bacteria, molds and algae
B. Many disease-causing microorganisms
E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
Chemical Control
349. Chlorine disinfectants destroy __________(which has a rotten egg odor) and remove
ammonia and other nitrogenous compounds that have unpleasant tastes and hinder
disinfection. They also help to remove iron and manganese from raw water.
A. Cryptosporidium parvum and Giardia lamblia
D. Hydrogen sulfide
B. Many disease-causing microorganisms
E. Chlorine disinfectants
C. Nitrogenous compounds
F. None of the Above
Water Treatment
350. Every day, approximately 170,000 (U.S. EPA, 2002) ____________treat and convey
billions of gallons of water through approximately 880,000 miles (Kirmeyer, 1994) of distribution
system piping to U.S. homes, farms and businesses.
A. Chlorine residual
D. Low levels of color and turbidity (cloudiness)
B. Public water systems
E. Distribution system piping
C. Chemical or biological contamination
F. None of the Above
351. Broadly speaking, water is treated to render it suitable for human use and consumption.
While the primary goal is to produce a biologically (disinfected) and chemically safe product,
other objectives also must be met, including: no objectionable taste or odor;
___________(cloudiness); and chemical stability (non-corrosive and non-scaling). Individual
facilities customize treatment to address the particular natural and manmade contamination
characteristic of their raw water.
A. Chlorine residual
D. Low levels of color and turbidity
B. Sediments
E. Distribution system piping
C. Chemical or biological contamination
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
352. Surface water usually presents a greater treatment challenge than groundwater, which is
naturally filtered as it percolates through _______________.
A. Chlorine residual
D. Low levels of color and turbidity (cloudiness)
B. Sediments
E. Distribution system piping
C. Chemical or biological contamination
F. None of the Above
353. Surface water is laden with organic and mineral particulate matter, and may harbor
protozoan parasites such as______________.
A. Total Coliform (TC)
D. Cryptosporidium parvum and Giardia lamblia
B. Indicator organisms
E. Giardia
C. Cholera, polio, typhoid, hepatitis
F. None of the Above
Water Distribution
354. In storage and distribution, drinking water must be kept safe from microbial contamination.
Frequently, slippery films of bacteria, known as biofilms, develop on the inside walls of pipes
and storage containers. Among__________________, chlorination is unique in that a predetermined chlorine concentration may be designed to remain in treated water as a measure of
protection against harmful microbes encountered after leaving the treatment facility.
A. Microbial contamination D. Disinfection techniques
B. Potential threats
E. Cost-effective methods
C. Critical assets
F. None of the Above
355. In the event of a significant intrusion of pathogens resulting, for example, from a broken
water main, the level of the average “____________” will be insufficient to disinfect
contaminated water. In such cases, it is the monitoring of the sudden drop in the chlorine
residual that provides the critical indication to water system operators that there is a source of
contamination in the system.
A. Chlorine residual
D. Low levels of color and turbidity (cloudiness)
B. Potential threats
E. Distribution system piping
C. Chemical or biological contamination
F. None of the Above
The Challenge of Disinfection Byproducts
356. While protecting against microbial contamination is the top priority, water systems must
also control disinfection byproducts (DBPs), ________________when chlorine and other
disinfectants react with natural organic matter in water. In the early 1970s, EPA scientists first
determined that drinking water chlorination could form a group of byproducts known as
trihalomethanes (THMs), including chloroform. EPA set the first regulatory limits for THMs in
1979.
A. Microbial contamination D. Chemical compounds formed unintentionally
B. Potential threats
E. Cost-effective methods
C. Critical assets
F. None of the Above
357. While the available evidence does not prove that ___________in drinking water cause
adverse health effects in humans, high levels of these chemicals are certainly undesirable.
Cost-effective methods to reduce DBP formation are available and should be adopted where
possible.
A. Microbial contamination D. Vulnerability assessments
B. Potential threats
E. DBPs
C. Critical assets
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Chlorine and Water System Security
358. The prospect of a terrorist attack has forced all water systems, large and small, to reevaluate and upgrade______________. Since September 11th, 2001, water system managers
have taken unprecedented steps to protect against possible attacks such as chemical or
biological contamination of the water supply, disruption of water treatment or distribution, and
intentional release of treatment chemicals.
A. Chlorine residual
D. Low levels of color and turbidity (cloudiness)
B. Existing security measures
E. Vulnerability assessments
C. Chemical or biological contamination
F. None of the Above
359. With passage of the Public Health Security and Bioterrorism Response Act of 2002,
Congress required community water systems to assess their vulnerability to a terrorist attack
and other intentional acts. As part of these vulnerability assessments, systems
assess______________.
A. Microbial contamination D. The transportation, storage and use of treatment chemicals
B. Potential threats
E. Cost-effective methods
C. Critical assets
F. None of the Above
360. These chemicals are both critical assets (necessary for delivering safe water) and
______________ (may pose significant hazards, if released).
A. Microbial contamination D. Vulnerability assessments
B. Potential threats
E. Potential vulnerabilities
C. Critical assets
F. None of the Above
361. Water systems using elemental chlorine, in particular, must determine whether existing
protection systems are adequate. If not, they must consider additional measures to reduce the
likelihood of an attack or to mitigate the______________________.
A. Microbial contamination D. Vulnerability assessments
B. Potential threats
E. Potential consequences
C. Critical assets
F. None of the Above
362. Disinfection is crucial to water system security, providing the “front line” of defense against
biological contamination. However, _______________in no way guarantee safety from
biological attacks. Additional research and funding are needed to improve prevention, detection
and responses to potential threats.
A. Microbial contamination
D. Vulnerability assessments
B. Potential threats
E. Cost-effective methods
C. Conventional treatment barriers F. None of the Above
The Future of Chlorine Disinfection
363. Despite a range of new challenges, drinking water chlorination will remain a cornerstone of
waterborne disease prevention. ___________ cannot be provided by any other single
disinfectant.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Chlorine’s wide array of benefits
C. THMs and HAAs
F. None of the Above
65
Chlorination 303 8/9/2015 Assignment
364. While _____________ (including chlorine dioxide, ozone, and ultraviolet radiation) are
available, all disinfection methods have unique benefits, limitations, and costs. Water system
managers must consider these factors, and design a disinfection approach to match each
system’s characteristics and source water quality.
A. Haloforms
D. Alternative disinfectants
B. Trihalomethane(s)
E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
Understanding Disinfection Byproducts (DBPS)
365. _____________ have been widely used by public water systems (along with filtration) to
protect the public from microbial pathogens in drinking water. DBPs are formed when certain
disinfectants react with DBP precursors (organic and inorganic materials) in source waters.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Chlorine and other chemical disinfectants
C. THMs and HAAs
F. None of the Above
366. In most cases, natural organic matter (NOM) is an important factor that affects the levels
of DBPs that form (NOM is usually measured as TOC). The levels of _________ in drinking
water can vary significantly from one point in a distribution system to another, as many continue
to form in the distribution system. DBP levels are generally higher in surface water systems
because surface water usually contains higher DBP precursor levels and requires stronger
disinfection.
A. Haloforms
D. Alternative disinfectants
B. Trihalomethane(s)
E. DBPs
C. Total concentration
F. None of the Above
Updating the Safe Drinking Water Act Regulations
367. EPA has regulated DBPs in drinking water since 1979. The first DBP standards limited
__________ to 100 parts per billion (ppb) for systems serving more the 10,000 people. In the
1996 Safe Drinking Water Act (SDWA) reauthorization, Congress called for EPA to revise its
standards for disinfectants and DBPs in two stages. The revised regulations are designed to
reduce potential DBP risks, while ensuring that drinking water is protected from microbial
contamination.
A. Potential DBP risks
D. Many trihalomethanes
B. THM levels
E. Enforceable Maximum Contaminant Levels (MCLs)
C. THMs and HAAs
F. None of the Above
Stage 1 DBP Rule
368. In December 1998 USEPA issued the ______________ (Stage 1 DBP) rule. The
regulations are based on an agreement between members of a Federal Advisory Committee
that included representatives from water utilities, the Chlorine Chemistry Division of the
American Chemistry Council, public health officials, environmentalists and other stakeholder
groups. This diverse group of experts developed a consensus set of recommendations to costeffectively reduce DBP levels, without compromising protection from microbial contaminants.
A. Haloforms
D. MCL(s)
B. Trihalomethane(s)
E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
369. ______________ mandates a process called enhanced coagulation to remove natural
organic matter, reducing the potential for DBPs to form. The rule also sets enforceable
Maximum Contaminant Levels (MCLs) for total trihalomethanes at 80 ppb and the sum of five
Haloacetic Acids (HAAs) at 60 ppb.
A. Potential DBP risks
D. Many trihalomethanes
B. The Stage 1 DBP rule
E. Enforceable Maximum Contaminant Levels (MCLs)
C. THMs and HAAs
F. None of the Above
370. These ____________ are based on system-wide running annual averages, meaning that
concentrations may be higher at certain times and at certain points in the system, as long as the
system-wide average for the year is below the MCL. In developing the Stage 1 DBP rule, EPA
was very cautious about encouraging the use of alternative disinfectants.
A. Haloforms
D. MCLs
B. Trihalomethane(s)
E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
371. The Agency recognized that alternative disinfectants might reduce ________________,
but produce other, less understood, byproducts. The Agency also avoided making
recommendations that would encourage utilities to reduce the level of disinfection currently
being practiced.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Enforceable Maximum Contaminant Levels (MCLs)
C. THMs and HAAs
F. None of the Above
Total Trihalomethanes
372. _________________are chemical compounds in which three of the four hydrogen atoms
of methane (CH4) are replaced by halogen atoms.
A. Haloforms
D. MCL(s)
B. Trihalomethanes (THMs) E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
373. Many trihalomethanes find uses in industry as solvents or refrigerants. _________ are
also environmental pollutants, and many are considered carcinogenic.
A. Potential DBP risks
D. Many trihalomethanes
B. THMs
E. Enforceable Maximum Contaminant Levels (MCLs)
C. THMs and HAAs
F. None of the Above
374. Trihalomethanes with all the same halogen atoms are called ______________.
A. Haloforms
D. MCL(s)
B. Trihalomethane(s)
E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
375. Trihalomethanes are formed as a by-product predominantly when chlorine is used to
disinfect water for drinking. They represent one group of chemicals generally referred to
as__________. They result from the reaction of chlorine and/or bromine with organic matter
present in the water being treated.
A. Haloforms
D. MCL(s)
B. Disinfection by-products E. Stage 1 Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
376. The THMs produced have been associated through epidemiological studies with some
adverse health effects. Many governments set limits on the amount permissible in drinking
water. However, trihalomethanes are only one group of many hundreds of__________—the
vast majority of which are not monitored—and it has not yet been clearly demonstrated which of
these are the most plausible candidate for causation of these health effects.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Possible disinfection by-products
C. THMs and HAAs
F. None of the Above
377. In the United States, the EPA limits the total concentration of the four chief constituents
(chloroform, bromoform, bromodichloromethane, and dibromochloromethane), referred to
as__________, to 80 parts per billion in treated water.
A. Haloforms
D. MCL(s)
B. Trihalomethane(s)
E. Total trihalomethanes (TTHM)
C. Total concentration
F. None of the Above
THM Treatment
378. THM levels tend to increase with pH, temperature, time, and the level of "____________"
present. Precursors are organic material which reacts with chlorine to form THM's. One way to
decrease THM's is to eliminate or reduce chlorination before the filters and to reduce
precursors.
A. Haloforms
D. MCL(s)
B. Trihalomethane(s)
E. Precursors
C. Total concentration
F. None of the Above
379. There are more precursors present before filtration, so we want to reduce or eliminate the
time chlorine is in contact with this water. If some oxidation before filtration is required, an
alternative disinfectant like ___________________could be considered. Note that this may not
be an option if prechlorination is necessary to achieve required CT values.
A. Haloforms
D. Potassium permanganate or peroxide
B. Trihalomethane(s)
E. Disinfectants and Disinfection Byproducts
C. Total concentration
F. None of the Above
380. The EPA has indicated that the best available technology for THM control at treatment
plants is removal of_______________ through "enhanced coagulation".
A. Haloforms
D. MCL(s)
B. Trihalomethane(s)
E. Precursors
C. Total concentration
F. None of the Above
381. Enhanced coagulation refers to the process of optimizing the filtration process to maximize
removal of _____________________.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Precursors
C. THMs and HAAs
F. None of the Above
382. Removal is improved by decreasing pH (to levels as low as 4 or 5), increasing the feed
rate of __________________ , and possibly using ferric coagulants instead of alum.
A. Potential DBP risks
D. Many trihalomethanes
B. THM(s)
E. Enforceable Maximum Contaminant Levels (MCLs)
C. THMs and HAAs
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Understanding Cryptosporidiosis
383.
Cryptosporidium is __________________because its transmission has increased
dramatically over the past two decades. Evidence suggests it is newly spread in increasingly
popular day-care centers and possibly in widely distributed water supplies, public pools and
institutions such as hospitals and extended-care facilities for the elderly.
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
384. Recognized in humans largely since 1982 and the start of the AIDS epidemic,
Cryptosporidium is able to cause potentially life-threatening disease in the growing number of
immunocompromised patients. ________________ was the cause of the largest reported
drinking water outbreak in U.S. history, affecting over 400,000 people in Milwaukee in April,
1993. More than 100 deaths are attributed to this outbreak. Cryptosporidium remains a major
threat to the U.S. water supply (Ibid.).
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
385. The EPA is developing new drinking water regulations to reduce ___________ and other
resistant parasitic pathogens. Key provisions of the Long Term 2 Enhanced Surface Water
Treatment Rule include source water monitoring for Cryptosporidium, inactivation by all
unfiltered systems; and additional treatment for filtered systems based on source water
Cryptosporidium concentrations.
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
386. EPA will provide a range of treatment options to achieve the inactivation requirements.
Systems with high concentrations of ________________ in their source water may adopt
alternative disinfection methods (e.g., ozone, UV, or chlorine dioxide).
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
387. However, most water systems are expected to meet EPA requirements while continuing to
use chlorination. Regardless of the primary disinfection method used, water systems must
continue to maintain residual levels of ______________in their distribution systems.
A. High-test calcium hypochlorite(s)
D. Chlorine-based disinfectants
B. Calcium hypochlorite tablets
E. Chlorine dioxide
C. Hypochlorous acid
F. None of the Above
Understanding Giardia lamblia
388. _____________, discovered approximately 20 years ago, is another emerging waterborne
pathogen. This parasitic microorganism can be transmitted to humans through drinking water
that might otherwise be considered pristine.
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
389. There is a distinct pattern to the emergence of____________. First, there is a general
recognition of the effects of the pathogen in highly susceptible populations such as children,
cancer patients and the immunocompromised. Next, practitioners begin to recognize the
disease and its causative agent in their own patients, with varied accuracy.
A. Cryptosporidium
D. New pathogens
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
390. At this point, some may doubt the proposed agent is the causative agent, or insist that the
disease is restricted to certain types of patients. Finally, a single or series of large outbreaks
result in improved attention to preventive efforts. From the 1960’s to the 1980’s this sequence of
events culminated in the recognition of ______________ as a cause of gastroenteritis
(Lindquist, 1999).
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
Understanding Waterborne Diseases
391. Detection and investigation of waterborne disease outbreaks is the primary responsibility
of local, state and territorial public health departments, with voluntary reporting to the CDC. The
CDC and the U.S. Environmental Protection Agency (EPA) collaborate to track
________________of both microbial and chemical origins. Data on drinking water and
recreational water outbreaks and contamination events have been collected and summarized
since 1971.
A. Waterborne disease outbreaks
D. Amounts of disinfection byproducts
B. Diagnosed cases of waterborne illness E. Waterborne disease outbreaks
C. Treatment measures
F. None of the Above
392. While useful, statistics derived from surveillance systems do not reflect the true incidence
of _______________because many people who fall ill from such diseases do not consult
medical professionals.
A. Waterborne disease outbreaks D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
393. For those who do seek medical attention, attending physicians and laboratory and hospital
personnel are required to report diagnosed cases of _____________to state health
departments. Further reporting of these illness cases by state health departments to the CDC is
voluntary, and statistically more likely to occur for large outbreaks than small ones.
A. Waterborne disease outbreaks
D. Amounts of disinfection byproducts
B. Diagnosed cases of waterborne illness E. Waterborne illness
C. Treatment measures
F. None of the Above
394. Despite these limitations, surveillance data may be used to evaluate the relative degrees
of risk associated with different types of_____________, problems in current technologies and
operating conditions, and the adequacy of current regulations. (Craun, Nwachuku, Calderon,
and Craun, 2002).
A. Source water and systems
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Disinfection Rules
Disinfection Byproduct Regulations
395. In December 1998, the EPA established the Stage 1 Disinfectants/Disinfection Byproducts
Rule that requires public water systems to use treatment measures to reduce the formation of
disinfection byproducts and to meet the following specific standards:
Currently trihalomethanes are regulated at a maximum allowable annual average level of 100
parts per billion for water systems serving over 10,000 people under the ____________finalized
by the EPA in 1979.
A. Waterborne disease outbreaks D. Amounts of disinfection byproducts
B. Total Trihalomethane Rule
E. Trihalomethanes
C. Treatment measures
F. None of the Above
396. The Stage 1 Disinfectant/Disinfection Byproduct Rule standards became effective for
trihalomethanes and _____________listed above in December 2001 for large surface water
public water systems. Those standards became effective in December 2003 for small surface
water and all ground water public water systems.
A. Other disinfection byproducts
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
397. Disinfection byproducts are formed when disinfectants used in water treatment plants
react with bromide and/or natural organic matter (i.e., decaying vegetation) present in the
source water. Different disinfectants produce different types or __________________.
A. Waterborne disease outbreaks
D. Amounts of disinfection byproducts
B. Diagnosed cases of waterborne illness E. Trihalomethanes
C. Treatment measures
F. None of the Above
398. _________________ for which regulations have been established have been identified in
drinking water, including trihalomethanes, haloacetic acids, bromate, and chlorite.
A. Waterborne disease outbreaks
D. Disinfection byproducts
B. Diagnosed cases of waterborne illness E. Trihalomethanes
C. Treatment measures
F. None of the Above
Bromate
399. Bromate is a chemical that is formed when ozone used to disinfect drinking water reacts
with naturally occurring bromide found in source water. The EPA has established the Stage 1
Disinfectants/Disinfection Byproducts Rule to regulate _________at annual average of 10 parts
per billion in drinking water.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. Bromate
E. Disinfection byproducts
C. Trihalomethanes F. None of the Above
400. This standard became effective for large public water systems by December 2001 and
for small surface water and _____________back in December 2003.
A. Waterborne disease outbreaks
D. Amounts of disinfection byproducts
B. Diagnosed cases of waterborne illness E. All ground public water systems
C. Treatment measures
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Microbial Regulations
401.
One of the key regulations developed and implemented by the United States
Environmental Protection Agency (USEPA) to counter pathogens in drinking water is the
____________. Among its provisions, the rule requires that a public water system, using
surface water (or ground water under the direct influence of surface water) as its source, have
sufficient treatment to reduce the source water concentration of Giardia and viruses by at least
99.9% and 99.99%, respectively.
A. Long Term 1 Rule
D. Surface Water Treatment Rule
B. Maximum Contaminant Level Goal (MCLG)
E. Interim Enhanced Surface Water
C. Stage 1 Byproducts Rule
F. None of the Above
402. The ______________ specifies treatment criteria to assure that these performance
requirements are met; they include turbidity limits, disinfectant residual, and disinfectant contact
time conditions.
A. Long Term 1 Rule
D. Surface Water Treatment Rule
B. Maximum Contaminant Level Goal (MCLG)
E. Interim Enhanced Surface Water
C. Stage 1 Byproducts Rule
F. None of the Above
403. The ______________ was established in December 1998 to control Cryptosporidium, and
to maintain control of pathogens while systems lower disinfection byproduct levels to comply
with the Stage 1 Disinfectants/Disinfection Byproducts Rule.
A. Long Term 1 Enhanced Surface Water Treatment Rule
B. Maximum Contaminant Level Goal (MCLG)
C. Stage 1 Disinfectants/Disinfection Byproducts Rule
D. Surface Water Treatment Rule
E. Interim Enhanced Surface Water Treatment Rule
F. None of the Above
404. The EPA established a ________________ of zero for all public water systems and a 99%
removal requirement for Cryptosporidium in filtered public water systems that serve at least
10,000 people. The new rule will tighten turbidity standards by December 2001. Turbidity is an
indicator of the physical removal of particulates, including pathogens.
A. Long Term 1 Enhanced Surface Water Treatment Rule
B. Maximum Contaminant Level Goal (MCLG)
C. Stage 1 Disinfectants/Disinfection Byproducts Rule
D. Surface Water Treatment Rule
E. Interim Enhanced Surface Water Treatment Rule
F. None of the Above
405. The EPA is also planning to develop other rules to further control pathogens. The EPA has
promulgated a Long Term 1 Enhanced Surface Water Treatment Rule, for systems serving
fewer than 10,000 people. This is to improve physical removal of Cryptosporidium, and to
maintain control of pathogens while systems comply with _______________________.
A. Long Term 1 Enhanced Surface Water Treatment Rule
B. Maximum Contaminant Level Goal (MCLG)
C. Stage 1 Disinfectants/Disinfection Byproducts Rule
D. Surface Water Treatment Rule
E. Interim Enhanced Surface Water Treatment Rule
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Microbes - More Information in the water Monitoring Section
406. __________________ are common in the environment and are generally not harmful.
However, the presence of these bacteria in drinking water is usually a result of a problem with
the treatment system or the pipes which distribute water, and indicates that the water may be
contaminated with germs that can cause disease.
A. Fecal Coliform and E coli
D. Cryptosporidiosis
B. Giardia lamblia
E. Coliform bacteria
C. Microorganisms
F. None of the Above
407. _______________ are bacteria whose presence indicates that the water may be
contaminated with human or animal wastes. Microbes in these wastes can cause short-term
effects, such as diarrhea, cramps, nausea, headaches, or other symptoms.
A. Fecal Coliform and E coli
D. Cryptosporidiosis
B. Giardia lamblia
E. Coliform bacteria
C. Microorganisms
F. None of the Above
408. Cryptosporidium is a parasite that enters lakes and rivers through sewage and animal
waste. It causes cryptosporidiosis, a mild gastrointestinal disease. However, the disease can be
severe or fatal for people with severely weakened immune systems. The EPA and CDC have
prepared advice for those with severely compromised immune systems who are concerned
about_____________ .
A. Fecal Coliform and E coli
D. Cryptosporidiosis
B. Giardia lamblia
E. Cryptosporidium
C. Microorganisms
F. None of the Above
409. Giardia lamblia is a parasite that enters lakes and rivers through sewage and animal
waste. It causes ________________(e.g. diarrhea, vomiting, and cramps).
A. Fecal Coliform and E coli
D. Cryptosporidiosis
B. Gastrointestinal illness
E. Coliform bacteria
C. Microorganisms
F. None of the Above
Chlorine Review
410. Chlorine Demand: The minimum amount of _____________needed to react in a water
purification system; used as a monitoring measurement by system operators.
A. Chlorine
D. Monitoring measurement
B. Liquid
E. Ammonia or organic amines
C. Total chlorine
F. None of the Above
411. Chlorine Residual: The concentration of chlorine in the water after the chlorine demand
has been satisfied. The concentration is normally expressed in terms of total chlorine residual,
which includes both the free and combined or______________________________.
A. Fusible plug
D. Total chlorine
B. Chlorine cylinder
E. Residual chlorine
C. Chemically bound chlorine residuals
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
412. Combined Chlorine Residual: The amount of chlorine used up in a water purification
system; used as a monitoring measurement by system operators. _________________is
defined as the residual chlorine existing in water in chemical combination with ammonia or
organic amines which can be found in natural or polluted waters. Ammonia is sometimes
deliberately added to chlorinated public water supplies to provide inorganic chloramines.
A. Combined chlorine
D. Monitoring measurement
B. Liquid
E. Ammonia or organic amines
C. Total chlorine
F. None of the Above
413. Free Chlorine: Free chlorine is defined as the concentration of ______________ in water
present as dissolved gas (Cl2), hypochlorous acid (HOCl), and/or hypochlorite ion (OCl-).
A. Chlorine Demand D. Total chlorine
B. Chlorine total
E. Residual chlorine
C. Chlorinator
F. None of the Above
414. Their relative proportions are determined by the pH value and temperature. Regardless of
whether pre-chloration is practiced or not, a ______________of at least 10 mg/L should be
maintained in the clear well or distribution reservoir immediately downstream from the point of
post-chlorination and .2 mg/L in the distribution system to guard against backflow.
A. Chlorine Demand
D. Total chlorine
B. Chlorine total
E. Residual chlorine
C. Free chlorine residual
F. None of the Above
415. Total Chlorine Residual: The total of free residual and combined residual chlorine in a
water purification system; used as a monitoring measurement by system operators.
_____________ is the sum of free and combined chlorine.
A. Chlorine Demand D. Total chlorine
B. Chlorine total
E. Residual chlorine
C. Chlorinator
F. None of the Above
416. When chlorinating most potable water supplies, total chlorine is essentially equal to free
chlorine since the concentration of ammonia or organic nitrogen compounds (needed to
form______________) will be very low. When chloramines are present in the municipal water
supply, then total chlorine will be higher than free chlorine.
A. Chlorine Demand
D. Total chlorine
B. Chlorine total
E. Residual chlorine
C. Combined chlorine
F. None of the Above
417. What is the purpose of a fusible plug, at what temperature does it melt, and where is it
located on 150-lb. and 1-ton cylinders? _______________ is a safety device that melts. If the
temperature of a full Cl2 cylinder is increased by 50o F or 30o C, a rupture may occur. It will melt
at 158 to 165 degrees F. It is found on the side of a 1 ton container and on top of the 150 pound
cylinder and is located in the valve below the valve seat.
A. Fusible plug
D. Chlorine valve
B. Chlorine cylinder
E. Yoke
C. Chlorinator
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
418. What is the correct procedure to follow in changing a chlorine cylinder and what item
should always be replaced with a new one in doing so? Hook up the __________ to the
container or cylinder with the chlorine valve turned off. Use the gas side not the liquid if using a
1 ton container. Remove the cylinder valve outlet cap and check the valve face or damage.
A. Fusible plug
D. Chlorine valve
B. Chlorine cylinder
E. Yoke
C. Chlorinator
F. None of the Above
419. Clean with wire brush if necessary. If the valve face is smooth, clean proceed with hooking
up the cylinder. Check the inlet face of the ____________ and clean if necessary.
A. Fusible plug
D. Chlorine valve
B. Chlorine cylinder
E. Yoke
C. Chlorinator
F. None of the Above
420. Place a new lead gasket on the chlorinator inlet, place the chlorinator on the cylinder
valve, install the yoke clamp and slowly tighten the _______until the two faces are against the
lead gasket. Tighten the yoke, compressing the gasket one half to three quarters turn, do not
over tighten. Replace the lead gasket with every change out.
A. Fusible plug
D. Chlorine valve
B. Chlorine cylinder
E. Yoke clamp
C. Chlorinator
F. None of the Above
Halides
421. These elements are diatomic molecules in their natural form. They require one more
electron to fill their outer electron shells, and so have a tendency to form a singly-charged
negative ion. This negative ion is referred to as a halide ion; ____________ containing these
ions are known as halides.
A. Salts
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. Primary disinfectant
F. None of the Above
422. Halide ions combined with single hydrogen atoms form the hydrohalic acids (i.e., HF, HCl,
HBr, HI), a series of particularly strong acids. (HAt, or "__________________", should also
qualify, but it is not typically included in discussions of hydrohalic acid due to astatine's extreme
instability toward alpha decay.)They react with each other to form interhalogen compounds.
A. HCl
D. Chlorine gas
B. HOCl
E. The hypochlorite ion (OCl-)
C. Hydrastatic acid
F. None of the Above
423. Diatomic interhalogen compounds (BrF, ICl, ClF, etc.) bear strong superficial resemblance
to the pure halogens. Many synthetic organic compounds such as plastic polymers, and a few
natural ones, contain halogen atoms; these are known as halogenated compounds
or____________________.
A. Organic halides
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. Primary disinfectant
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Chlorine
424. Chlorine is by far the most abundant of the halogens, and the only one needed in relatively
large amounts (as chloride ions) by humans. For example, chloride ions play a key role in brain
function by mediating the action of the _______________and are also used by the body to
produce stomach acid. Iodine is needed in trace amounts for the production of thyroid hormones
such as thyroxine.
A. Chloramines
D. Halogens
B. Chlorine dioxide
E. Inhibitory transmitter GABA
C. CXT formula
F. None of the Above
425. On the other hand, neither fluorine nor bromine are believed to be really essential for
humans, although small amounts of _____________can make tooth enamel resistant to decay.
A. Salts
D. Many synthetic organic compounds
B. CXT values
E. Fluoride
C. Primary disinfectant
F. None of the Above
Halogens
426. All ______________ have 7 electrons in their outer shells, giving them an oxidation
number of -1. The halogens exist, at room temperature, in all three states of matter:
A. Chloramines
D. Halogens
B. Chlorine dioxide
E. Chlorine concentrations
C. CXT formula
F. None of the Above
Factors in Chlorine Disinfection: Concentration and Contact Time
427. In an attempt to establish more structured operating criteria for water treatment
disinfection, the ______________ came into use in 1980. Based on the work of several
researchers, CXT values [ final free chlorine concentration (mg/L) multiplied by minimum
contact time (minutes)], offer water operators guidance in computing an effective combination of
chlorine concentration and chlorine contact time required to achieve disinfection of water at a
given temperature.
A. CXT concept
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. CXT formula
F. None of the Above
428. The ___________ demonstrates that if an operator chooses to decrease the chlorine
concentration, the required contact time must be lengthened. Similarly, as higher strength
chlorine solutions are used, contact times may be reduced (Connell, 1996).
A. CXT concept
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. CXT formula
F. None of the Above
Chloramines
429. ________________ are chemical compounds formed by combining a specific ratio of
chlorine and ammonia in water. Because chloramines are relatively weak as a disinfectant, they
are almost never used as a primary disinfectant.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. Bromate
E. Disinfection byproducts
C. Chloramines
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
430. Chloramines provide a durable residual, and are often used as a secondary disinfectant
for long distribution lines and where free chlorine demand is high. _______________ may also
be used instead of chlorine in order to reduce chlorinated byproduct formation and to remove
some taste and odor problems.
A. Chlorine dioxide D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. Bromate
E. Disinfection byproducts
C. Chloramines
F. None of the Above
Chlorine Dioxide
431. ________________is generated on-site at water treatment facilities. In most generators
sodium chlorite and elemental chlorine are mixed in solution, which almost instantaneously
forms chlorine dioxide.
A. Chlorine dioxide (ClO2) D. Trihalomethanes, haloacetic acids, bromate, and chlorite
B. Bromate
E. Disinfection byproducts
C. Chloramines
F. None of the Above
432. Chlorine dioxide characteristics are quite different from chlorine. In solution it is a
dissolved gas, which makes it largely unaffected by pH but volatile and relatively easily stripped
from ___________________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Solution
C. Chlorine dioxide
F. None of the Above
433. Chlorine dioxide is also a strong disinfectant and a selective oxidant. While chlorine
dioxide does produce _____________________ .
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. A residual it is only rarely used for this purpose
C. Chlorine dioxide
F. None of the Above
Factors in Chlorine Disinfection: Concentration and Contact Time
434. In an attempt to establish more structured operating criteria for water treatment
disinfection, the CXT concept came into use in 1980. Based on the work of several researchers,
_____________ [ final free chlorine concentration (mg/L) multiplied by minimum contact time
(minutes)], offer water operators guidance in computing an effective combination of chlorine
concentration and chlorine contact time required to achieve disinfection of water at a given
temperature.
A. CXT concept
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. CXT formula
F. None of the Above
435. The _____________ demonstrates that if an operator chooses to decrease the chlorine
concentration, the required contact time must be lengthened. Similarly, as higher strength
chlorine solutions are used, contact times may be reduced (Connell, 1996).
A. CXT concept
D. Many synthetic organic compounds
B. CXT values
E. Neither fluorine nor bromine
C. CXT formula
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Conclusion
436. Emerging waterborne pathogens constitute a major health hazard in both developed and
developing nations. A new dimension to the global epidemiology of cholera-an ancient scourgewas provided by the emergence of__________________.
A. Cholera
D. Vibrio cholerae O139
B. Legionella pneumophila E. Campylobacter
C. Shigellosis
F. None of the Above
437. Also, water-borne enterohaemorrhagic Escherichia coli (E. coli O157:H7), although
regarded as a problem of the industrialized west, has recently caused outbreaks in Africa.
Outbreaks of chlorine-resistant ___________ have motivated water authorities to reassess the
adequacy of current water-quality regulations.
A. Campylobacter
D. Cryptosporidium
B. Pathogen
E. Shigella dysenteriae
C. Pontiac fever
F. None of the Above
438. Of late, a host of other organisms, such as hepatitis viruses (including hepatitis E virus),
Campylobacter jejuni, microsporidia, cyclospora, _______________, calciviruses and
environmental bacteria like Mycobacterium spp, aeromonads, Legionella pneumophila and
multidrug-resistant Pseudomonas aeruginosa have been associated with water-borne illnesses.
A. Yersinia enterocolitica
D. Emergence of disinfection resistant variants
B. Legionella pneumophila E. Campylobacter
C. Shigellosis
F. None of the Above
439. The protection and enhancement of our nation’s water quality remains a chief concern of
the U.S. Environmental Protection Agency. The Office of Research and Development is
committed, through the ________________ efforts earlier described, to ensure that the most
effective and efficient methods are developed to identify, detect, and inactivate/remove
pathogens that may be present in our drinking water supplies.
A. Optimal pathogen removal techniques D. Primary methods used for the disinfection
B. Disinfection process
E. Extensive waterborne disease research
C. Environmental and regulatory impact
F. None of the Above
440. Life cycles, mechanisms of infection, protective or dormant states, emergence of
disinfection resistant variants, __________________, regrowth in distribution lines…all are
areas that must be investigated and understood to afford the water quality safeguards that are
so often taken for granted. The successes and failures of these research efforts, relayed to the
public and appropriate federal, state, and local agencies, have helped to ensure safe drinking
water.
A. Optimal pathogen removal techniques D. Primary methods used for the disinfection
B. Disinfection process
E. Extensive waterborne disease research
C. Environmental and regulatory impact
F. None of the Above
Salmonella Typhi
441. Salmonella typhi, the basics. It's a bacteria. It causes diarrheal illness, also known as
____________. And humans are the reservoir for this pathogen.
A. Campylobacter
D. Typhoid fever
B. Pathogen
E. Shigella dysenteriae
C. Pontiac fever
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
442. Salmonella typhi, prevention. Prevention strategies for this pathogen include source
protection, halogenation of water, and___________________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Shigella Species
443. Shigella species, the basics. It's a bacteria. It causes diarrheal illness known as
shigellosis. Humans and primates are the reservoir for this pathogen. Shigella species, in the
United States two-thirds of the shigellosis in the U.S. is caused by___________, and the
remaining one-third is caused by Shigella flexnieri. In developing countries, Shigella dysenteriae
is the primary cause of illness associated with this pathogen.
A. Campylobacter
D. Shigella sonnei
B. Pathogen
E. Shigella dysenteriae
C. Pontiac fever
F. None of the Above
444. Shigella species prevention. Prevention strategies for this pathogen include source
protection, halogenation of water, and ________________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Campylobacter
445. Campylobacter, the basics. It's a bacteria. It causes diarrheal illness. And Campylobacter
is primarily associated with poultry, animals, and humans. Campylobacter prevention.
Prevention strategies for this pathogen include source protection, halogenation of water, and
__________________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Vibrio Cholerae
446. Vibrio cholerae, the basics. It's a bacteria. It causes diarrheal illness, also known as
cholera. It is typically associated with aquatic environments, shell stocks, and human. Vibrio
cholerae has also been associated with ship ballast water.
A. Campylobacter
D. Typhoid fever
B. Pathogen
E. Shigella dysenteriae
C. Pontiac fever
F. None of the Above
447. Vibrio cholerae prevention. Prevention strategies for this pathogen include source
protection, halogenation of water, and __________________.
A. Chlorine
D. Chlorine gas
B. Sodium hypochlorite
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Legionella
448. Legionella, the basics. It's a bacteria. It causes a respiratory illness known as
legionellosis. There are two illnesses associated with legionellosis: the first, Legionnaire's
disease, which causes a severe pneumonia, and the second, _____________, which is a
nonpneumonia illness; it's typically an influenza-like illness, and it's less severe. Legionella is
naturally found in water, both natural and artificial water sources.
A. Campylobacter
D. Typhoid fever
B. Pathogen
E. Shigella dysenteriae
C. Pontiac fever
F. None of the Above
449. Legionella, prevention. ______________at or above 50 degrees Centigrade and cold
water below 20 degrees Centigrade can prevent or control the proliferation of Legionella in
water systems. Hot water in tanks should be maintained between 71 and 77 degrees
Centigrade.
A. Maintaining hot water systems D. Chlorine gas
B. Sodium hypochlorite
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Pseudomonas
450. Pseudomonas, the basics. It's a bacteria. It is caused by dermal contact with water. It can
cause dermatitis, which is an inflammation of the skin, or it can cause otitis, which is an infection
of the ear. __________________ is typically associated with soil and water.
A. Hepatitis A virus D. Pseudomonas
B. Diarrheal illness E. Waterborne outbreaks
C. Cryptosporidium F. None of the Above
451. Pseudomonas prevention. Proper maintenance and disinfection of recreational water
systems is important in preventing ____________________.
A. Pathogen
D. Pseudomonas
B. Cryptosporidium E. Salmonellosis
C. Hepatitis A virus F. None of the Above
Hepatitis A
452. Hepatitis A, the basics. It's a virus. It causes inflammation of the liver. And the reservoir
for ___________ is humans.
A. Hepatitis A virus D. Hepatitis B
B. Diarrheal illness E. Waterborne outbreaks
C. Cryptosporidium F. None of the Above
Hepatitis A, Prevention
453. Prevention strategies for this pathogen include source protection and adequate
disinfection. Fecal matter can protect ______________ from chlorine. Additionally, Hepatitis A
virus is resistant to combined chlorines, so it is important to have an adequate free chlorine
residual.
A. Hepatitis A virus D. Hepatitis B
B. Diarrheal illness E. Waterborne outbreaks
C. Cryptosporidium F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Norovirus
454. Norovirus, the basics. It's a virus. It causes diarrheal illness. And humans are the reservoir
for this virus. Norovirus, prevention. Prevention strategies for this pathogen
include_______________.
A. Maintaining hot water systems D. Chlorine gas
B. Source protection
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Cryptosporidium
455.
Cryptosporidium, the basics. It's a parasite. It causes diarrheal illness known
as____________. It is typically associated with animals and humans, and it can be acquired
through consuming fecally contaminated food, contact with fecally contaminated soil and water.
A. Pathogen
D. Cryptosporidiosis
B. Cryptosporidium E. Salmonellosis
C. Hepatitis A virus F. None of the Above
456. Cryptosporidium, prevention. Prevention strategies for this pathogen include source
protection. A CT value of 9,600 is required when dealing with fecally accidents. CT equals a
concentration, in parts per million, while time equals a contact time in minutes.
_______________ can also be prevented or eliminated by boiling water for one minute.
A. Hepatitis A virus D. Pseudomonas
B. Diarrheal illness E. Waterborne outbreaks
C. Cryptosporidium F. None of the Above
457. Filtration with an "absolute" pore size of one micron or smaller can eliminate _________.
And reverse osmosis is known to be effective as well.
A. Pathogen
D. Pseudomonas
B. Cryptosporidium E. Salmonellosis
C. Hepatitis A virus F. None of the Above
Giardia
458. Giardia, the basics. It is a parasite. It causes diarrheal illness known as giardiasis. It is
typically associated with water. It is the most common pathogen in waterborne outbreaks. It can
also be found in soil and food. And humans and animals are the reservoir for this pathogen.
Giardia prevention. Prevention strategies for this pathogen include _____________; filtration,
coagulation, and halogenation of drinking water.
A. Maintaining hot water systems D. Chlorine gas
B. Source protection
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Schistosomatidae
459. Schistosomatidae, the basics. It is a parasite. It is acquired through dermal contact,
cercarial dermatitis. It is commonly known as___________________. The reservoir for this
pathogen are aquatic snails and birds.
A. Swimmer's itch
D. Pseudomonas
B. Cryptosporidium E. Salmonellosis
C. Hepatitis A virus F. None of the Above
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Chlorination 303 8/9/2015 Assignment
460.
Schistosomatidae, prevention. Prevention strategies for this pathogen include
______________ or interrupting the life cycle of the parasite by treating birds with an
antihelmetic drug.
A. Maintaining hot water systems D. Eliminating snails with a molluscicide
B. Source protection
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
E-Coli Section
461. Escherichia coli. There are several pathogenic strains of Escherichia coli, which are
classified under enterovirulent E. coli. They are enterohemorrhagic, enteroinvasive,
enterotoxigenic, enteropathogenic, and enteroaggregative. Escherichia coli O157:H7, the
basics.
It's
a
bacteria.
It
causes
diarrheal
illness,
and
it's
classified
as___________________________.
A. An enterohemorrhagic E. coli
D. Pseudomonas
B. Escherichia coli O157:H7
E. Salmonellosis
C. Bacteria
F. None of the Above
462. In its most severe form, it can cause_______________. The reservoir for this bacteria are
cattle, deer, goats, and sheep. Humans can also be a reservoir. It is typically associated with
contaminated food and water.
A. Hemorrhagic colitis
D. Pseudomonas
B. Escherichia coli O157:H7
E. Salmonellosis
C. Bacteria
F. None of the Above
463.
E. coli O157:H7 prevention. Prevention strategies for this pathogen include
_____________, halogenation of water, or boiling water for one minute.
A. Maintaining hot water systems D. Eliminating snails with a molluscicide
B. Source protection
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
464. Salmonella species, the basics. It's a bacteria. It causes diarrheal illness known as
___________. Humans and animals are the reservoir, and it's typically associated with
contaminated food and water.
A. Pathogen
D. Pseudomonas
B. Escherichia coli O157:H7 E. Salmonellosis
C. Bacteria
F. None of the Above
465. Salmonella species, prevention. Prevention strategies for this pathogen include source
protection, halogenation of water, and also ____________________.
A. Maintaining hot water systems D. Eliminating snails with a molluscicide
B. Source protection
E. Boiling water for one minute
C. Chlorine dioxide
F. None of the Above
Alternatives Methods for Water Disinfection
466. Chlorine in water is over three times more effective as a disinfectant against Escherichia
coli than an equivalent concentration of bromine, and over six times more effective than an
equivalent concentration of______________ .
A. Bromine
D. Iodine
B. UV rays
E. Chemical process
C. UV disinfection
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Ultraviolet Disinfection
467. This process involves exposing water to_________________, which inactivates various
microorganisms. The technique has enjoyed increased application in wastewater treatment but
very limited application in potable water treatment.
A. Sterilizer
D. Ultraviolet (UV) radiation
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
468. The lamp itself does not come in to contact with water, the lamp is placed inside a quartz
tube, and the water is in contact with the outside of the quartz tube. Quartz is used in this case
since practically none of the UV rays are absorbed by the quartz, allowing all of the rays to
reach the water. Ordinary glass cannot be used since it will absorb the _______________,
leaving little for disinfection.
A. Bromine
D. UV reactor
B. UV rays
E. Chemical process
C. UV disinfection
F. None of the Above
469. The ____________will consist of a various number of lamps and tubes, depending upon
the quantity of water to be treated. As water enters the sterilizer, it is given a tangential flow
pattern so that the water spins over and around the quartz sleeves.
A. UV sterilizer
D. UV reactor
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
470. In this way the microorganisms spend maximum time and contact with the outside of the
quartz tube and the source of the _______________.
A. Sterilizer
D. UV reactor
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
471. The basic design flow of water of certain ___________is in the order of 2.0 gpm for each
inch of the lamp. Further, the units are designed so that the contact or retention time of the
water in the unit is not less than 15 seconds.
A. UV units
D. UV reactor
B. UV rays
E. Chemical process
C. UV disinfection
F. None of the Above
472. UV disinfection transfers electromagnetic energy from a mercury arc lamp to a pathogen's
DNA material, thus affecting its ability to replicate itself. UV's effectiveness depends on the
characteristics of the wastewater, the intensity of the ____________being emitted, the length of
time that the wastewater comes in contact with the UV radiation, and the arrangement of the UV
reactor.
A. UV radiation
D. UV reactor
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
473. UV has the advantage of being effective at inactivating viruses and, because it's a
physical process rather than a chemical process, there are no residual constituents remaining in
the treated wastewater after exposure to UV. Also, the contact time for the wastewater with the
____________is the shortest of any of the disinfectant strategies, lasting no longer than 20 to
30 seconds.
A. UV source
D. UV reactor
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
474. Disadvantages include the effects of turbidity in the water reducing the infiltration and
therefore the effectiveness of _____________ and the need to provide an effective cleaning and
replacement program for the UV components.
A. UV
D. UV reactor
B. UV rays
E. Ballasts and shields
C. UV disinfection
F. None of the Above
475. Ensuring that the _________ maintains good contact with the water requires control of the
water level within the channel to ensure that the UV is making total contact at the designed
depths.
A. UV
D. UV reactor
B. UV rays
E. Ballasts and shields
C. UV disinfection
F. None of the Above
476. Also, because of the heat generated by the electric components of the system, adequate
ventilation and cooling must be applied to the ___________to reduce heat build-up, otherwise
the ballasts could fail.
A. UV arrays
D. UV reactor
B. UV rays
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
477. UV lamps have a rated life of up to 14,000 hours, and should be routinely replaced at
12,000 hours or roughly every 1.5 years of continuous operation. The electrical consumption of
this system, combined with the cost of routine replacement of ________________, should be
considered against other systems.
A. UV
D. UV reactor
B. UV rays
E. Ballasts and shields
C. UV disinfection
F. None of the Above
478. The germicidal effect of ___________ is thought to be associated with its absorption by
various organic components essential to the cell’s functioning.
A. Sterilizer
D. UV reactor
B. UV
E. Electromagnetic energy
C. UV disinfection
F. None of the Above
479. For effective use of_____________, the water to be disinfected must be clean, and free of
any suspended solids. The water must also be colorless and must be free of any colloids, iron,
manganese, taste, and odor. These are conditions that must be met.
A. Ultraviolet
D. UV reactor
B. UV rays
E. Ballasts and shields
C. UV disinfection
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Strongest Oxidizing Agent
480. Ozone (O3) is probably the strongest oxidizing agent available for water treatment.
Although it is widely used throughout the world, is has not found much application in the United
States. _________is obtained by passing a flow of air or oxygen between two electrodes that
are subjected to an alternating current in the order of 10,000 to 20,000 volts.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Strongest oxidizing agent
C. Ozone
F. None of the Above
481. Liquid ozone is very unstable and can readily explode. As a result, it is not shipped and
must be manufactured on-site. Ozone is a ____________ at room temperature.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Strongest oxidizing agent
C. Light blue gas
F. None of the Above
482. It has a ____________similar to that sometimes noticed during and after heavy electrical
storms. In use, ozone breaks down into oxygen and nascent oxygen.
A. Self-policing pungent odor
D. Oxygen and nascent oxygen
B. THMs
E. Strongest oxidizing agent
C. Light blue gas
F. None of the Above
483. It is the nascent oxygen that produces the high oxidation and disinfections, and even
sterilization. Each water has its own_____________, in the order of 0.5 ppm to 5.0 ppm.
Contact time, temperature, and pH of the water are factors to be determined.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Strongest oxidizing agent
C. Ozone demand
F. None of the Above
484. Ozone acts as a complete disinfectant. It is an excellent aid to the flocculation and
coagulation process, and will remove practically all color, taste, odor, iron, and manganese. It
does not form chloramines or ______________, and while it may destroy some THMs, it may
produce others when followed by chlorination.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Flocculation and coagulation
C. Complete disinfectant
F. None of the Above
485. Ozone is not practical for complete removal of chlorine or chloramines, or of THM and
other inorganics. Further, because of the possibility of formation of other carcinogens (such as
aldehydes or phthalates) it falls into the same category as other disinfectants in that it can
produce____________.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Strongest oxidizing agent
C. DBPs
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Alternate Disinfectants Section Summary
Chloramines
486. Chloramine is a very weak disinfectant for ____________ reduction. It is recommended
that it be used in conjunction with a stronger disinfectant. It is best utilized as a stable
distribution system disinfectant.
A. Cryptosporidium
D. Giardia and virus
B. Chlorine-based disinfectants
E. Emerging waterborne pathogen
C. Giardia lamblia
F. None of the Above
487. In the production of chloramines the ammonia residuals in the finished water, when fed in
excess of stoichiometric amount needed, should be limited to inhibit growth of______________.
A. Cryptosporidium
D. An emerging parasitic protozoan pathogen
B. Chlorine-based disinfectants
E. Nitrifying bacteria
C. Giardia lamblia
F. None of the Above
Chlorine Dioxide
488. Chlorine dioxide may be used for either taste and odor control or as_______________ .
A. Post disinfectant
D. Total residual oxidants
B. ClO2/chlorite/chlorate
E. A pre-disinfectant
C. An oxidant
F. None of the Above
489. Total residual oxidants (including______________, but excluding chlorate) shall not
exceed 0.30 mg/L during normal operation or 0.50 mg/L (including chlorine dioxide, chlorite and
chlorate) during periods of extreme variations in the raw water supply.
A. Pre-disinfectant
D. Chlorine dioxide and chlorite
B. ClO2/chlorite/chlorate
E. 25% aqueous solution of sodium chlorite (NaClO2)
C. An oxidant
F. None of the Above
490. Chlorine dioxide provides good ___________________protection but its use is limited by
the restriction on the maximum residual of 0.5 mg/L ClO2/chlorite/chlorate allowed in finished
water. This limits usable residuals of chlorine dioxide at the end of a process unit to less than
0.5 mg/L.
A. Pre-disinfectant
D. Total residual
B. ClO2/chlorite/chlorate
E. Giardia and virus
C. An oxidant
F. None of the Above
491. Where chlorine dioxide is approved for use as an oxidant, the preferred method of
generation is to entrain chlorine gas into a packed reaction chamber with a
_____________________.
A. Pre-disinfectant
D. Total residual oxidants
B. ClO2/chlorite/chlorate
E. 25% aqueous solution of sodium chlorite (NaClO2)
C. An oxidant
F. None of the Above
492. Warning: Dry sodium chlorite is _______________in feed equipment if leaking solutions or
spills are allowed to dry out.
A. Pre-disinfectant
D. Oxidant
B. ClO2/chlorite/chlorate
E. Explosive and can cause fires
C. An oxidant
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
Ozone
493.
Ozone is a very effective disinfectant for both Giardia and viruses.
______________(Contact time) values must be determined for the ozone basin alone; an
accurate T10 value must be obtained for the contact chamber, residual levels measured through
the chamber and an average ozone residual calculated.
A. Ozone CT
D. Oxygen and nascent oxygen
B. Free and/or combined chlorine E. Strongest oxidizing agent
C. Residual levels
F. None of the Above
494. Ozone does not provide a ________________and should be used as a primary
disinfectant only in conjunction with free and/or combined chlorine.
A. Ozone CT
D. System residual
B. Free and/or combined chlorine E. Strongest oxidizing agent
C. Residual levels
F. None of the Above
495. Ozone does not produce ___________________(such as trihalomethanes) but it may
cause an increase in such byproduct formation if it is fed ahead of free chlorine; ozone may also
produce its own oxygenated byproducts such as aldehydes, ketones, or carboxylic acids.
A. Carcinogens
D. Oxygen and nascent oxygen
B. THMs
E. Chlorinated byproducts
C. Carboxylic acids
F. None of the Above
496. Ozone may also be used as
applied as a pre-disinfectant.
A. An oxidant
B. Free and/or combined chlorine
C. Residual levels
_____________for removal of taste and odor, or may be
D. System residual
E. Strongest oxidizing agent
F. None of the Above
Waterborne Pathogens Section
The reason we disinfect.
497. Bacteria, viruses and protozoan that cause disease are known as pathogens. Most
pathogens are generally associated with diseases that _________and affect people in a
relatively short amount of time, generally a few days to two weeks.
A. Limit the effects of organic material
D. An additional killing mechanism
B. Numerous alternative disinfection processes
E. Limit the travel of pathogens
C. Cause intestinal illness
F. None of the Above
How Diseases are Transmitted.
498. Pathogens that may cause waterborne outbreaks through drinking water have one thing in
common: they are spread by the_________________.
A. Fecal-oral, or feces-to-mouth, route
D. An additional killing mechanism
B. Numerous alternative disinfection processes
E. Waterborne outbreaks
C. Residual level of disinfection
F. None of the Above
499. Pathogens may get into water and spread when infected humans or animals pass the
bacteria, viruses, and _____________________in their stool. For another person to become
infected, he or she must take that pathogen in through the mouth.
A. Fecal Coliform and E coli D. Cryptosporidiosis
B. Protozoa
E. Coliform bacteria
C. Microorganisms
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
500. Waterborne pathogens are different from other types of pathogens such as the viruses
that cause influenza (the flu) or the bacteria that cause tuberculosis. __________________are
spread by secretions that are coughed or sneezed into the air by an infected person.
A. Fecal Coliform and E coli D. Influenza virus and tuberculosis bacteria
B. Giardia lamblia
E. Coliform bacteria
C. Microorganisms
F. None of the Above
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Chlorination 303 8/9/2015 Assignment
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Chlorination 303 8/9/2015 Assignment