Dr. Nabaa Shakir Hadi
Environment Protection (I)
University of Babylon/ College of Engineering
Environmental Engineering Dep
Subject:Environment Protection(I)
Dr. Nabaa Shakir Hadi
No. Subject
1 Pollution and Environmental Ethics
1.1
1.2
1.3
1.4
1.5
1.6
1.7
2
Water Pollution
2.1
2.2
2.3
2.4
2.5
2.6
2.7
3
Introduction
Water Resources
Water Pollution
Status of Surface Water Quality
Biochemical Oxygen Demand
The Effect of Oxygen-Demanding Wastes on Rivers
Water Quality in Lakes and Reservoirs
Water and Wastewater Treatment
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
4
Introduction
The Roots of Environmental Problem
Ethics
Environmental Ethics as Public Health
Environmental Ethics as Conservation andPreservation
Environmental Ethics as Caring for Nonhuman Nature
Application and Development of the Environmental Ethic
Introduction
Coagulation and Flocculation
Settling
Filtration
Disinfection
Wastewater Characteristics
Onsite Wastewater Disposal
Central Wastewater Treatment
Waste Heat
4.1
4.2
4.3
4.4
4.5
4.6
Introduction
The Role o f Cooling in Fossil and Nuclear Power Plants
Wet Cooling: Once -Through
Wet Cooling: Recirculating
Dry Cooling
Cooling Requirements and the Future o f Nuclear Power
2014-2015
Dr. Nabaa Shakir Hadi
5
Air Pollution
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
6
Introduction
Sources and Types of Solid Wastes
Quantities and Characteristics of Municipal Solid Waste
Collection
Disposal Options
Disposal of Unprocessed Refuse in Sanitary Landfills
litter
Pollution Prevention
Noise Pollution and Control
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
8
Introduction
Types and Sources of Gaseous Air Pollutants
Particulate Matter
Hazardous Air Pollutants
Global and Atmospheric Climate Change
Measurement of Air Quality
Reference Methods
Meteorology and Air Pollution
Solid Waste
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
7
Environment Protection (I)
Introduction
The Concept of Sound
Sound Pressure Level, Frequency, and Propagation
Sound Level
Measuring Transient Noise
The Acoustic Environment
Health Effects of Noise
Noise Control
Radioactive Pollution
8.1
8.2
8.3
8.4
8.5
8.6
8.7
Introduction
Atoms and Radiation
Types of Radiation
Radiations and Radioactivity decay
Radioactive Pollution and their Sources
Biological Effects of Ionizing Radiation on the Human Body
Radiation Doses and Radiation Effects
2014-2015
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
REFERENCES
No.
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
Item
Terence J. McGhee., 1991 "Water Supply and Sewerage," Sixth Edition,
McGraw-Hill Series in Water Resources and Environmental Engineering.
Bailey and Ollis., 2000 " Biochemical Engineering Fundamental," McGraw-Hill
Series in Water Resources and Environmental Engineering.
Chanlett.,1997 " Environmental Protection, " McGraw-Hill Series in Water
Resources and Environmental Engineering.
Eckenfelder.,1991 "Industrial Water Pollution Control," McGraw-Hill Series in
Water Resources and Environmental Engineering.
Metcalf and Eddy.,1980 " Wastewater Engineering ,Collection and Pumping of
Wastewater," McGraw-Hill Series in Water Resources and Environmental
Engineering.
Metcalf and Eddy., 1991 " Wastewater Engineering, Treatment, Disposal, Reuse."
McGraw-Hill Series in Water Resources and Environmental Engineering.
Peavy , Rowe, and Tchobanoglous., 1986 " Environmental Engineering,"
McGraw-Hill Series in Water Resources and Environmental Engineering.
Rich., 1995 " Low Maintenance , Mechanically – Simple wastewater Treatment
Systems," McGraw - Hill Series in Water Resources and Environmental
Engineering.
Sawyer and McCarty., 1991 " Chemistry for Environmental Engineers," McGrawHill Series in Water Resources and Environmental Engineering.
Tchobanoglous, Theisen , and Elissen.,1985 "Solid Wastes, Engineering
Principles and Management Issues," McGraw-Hill Series in Water Resources and
Environmental Engineering.
T.H.Y.Tubbutt ., 2002 " Principles of Water Quality ," Butterworth – Heiuemann,
McGraw-Hill Series in Water Resources and Environmental Engineering.
‫جامعة الموصل‬-‫ تأليف الدكتور طارق احمد محمود‬, "‫" علم وتكنولوجيا البيئة‬
)‫( الكتاب المقرر‬
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
CHAPTER 1
Pollution and Environmental Ethics
environmental pollution : as the contamination of air, water, or food in such a
manner as to cause real or potential harm to human health or well-being, or to
damage or harm nonhuman nature without justification.
Roots of Environmental Problem, including:
 Religions
 social and economic structure
 Science and Technology
Environmental ethics, including:
 environmental ethics as public health
 environmental ethics as conservation and preservation
 environmental ethics as caring for nonhumans.
CHAPTER 2
Water Pollution
Unusual Properties of Water.
 Density
 Melting and Boiling Points
 Specific Heat
 Heat of Vaporization
 Water as a Solvent
 Greenhouse Effect
The Hydrologic Cycle
The hydrological cycle: is the system which describes the distribution and
movement of water between the earth and its atmosphere.
 Evaporation: is when the sun heats up water in rivers or lakes or the ocean
and turns it into vapour or steam which rises in to the air.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
 Transpiration: Do plants sweat? Kind of. Transpiration is the process by
which plants lose water from their leaves. The water rises in to the air.
 Condensation: Water vapour in the air gets cold and changes back into
liquid, forming clouds. This is called condensation.
 Precipitation: occurs when so much water has condensed that the air cannot
hold it anymore. Water falls to the earth in the form of rain, hail, sleet or
snow.
Water Usage
A simple equation relates the key terms: water withdrawals, water returns, and
water consumption.
Withdrawals= Consumption+ Returns……………………………..(1)
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Freshwater use in the United States,1990. Total annual withdrawals are
about500km3.Note:Industry includes mining, agriculture includes irrigation and
livestock, and municipal includes public, domestic, and commercial uses.
Water Quality Definitions
• Contaminant : any constituent in the water deleterious to a particular end
use regardless of its origin and whether it occurs in the watershed, source or
in a water supply system
• Pollutant : any constituent in the water source deleterious to a particular end
use that is of anthropogenic origin
Water Pollution
Any chemical, biological and physical change in water quality that has a
harmful effect on living organisms or makes it unusable for agriculture
Types and Sources of Pollution
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Pollution of Streams and Lakes
Ocean Pollution
Groundwater Pollution
Drinking Water Quality
Waste Water Treatment
Water Legislation
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Sources of Pollution
• Point sources (e.g., factories, sewage treatment plants, mines, oil wells, oil
tankers)
• Nonpoint sources (e.g., acid deposition, substances picked up in runoff,
seepage into groundwater)
• Agriculture is largest source of water pollution in the U.S. (64% of
pollutants into streams and 57% of pollutants entering lakes)
Types of Pollution
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Disease-causing Agents – pathogens
Oxygen Demanding Agents – organic waste: manure
Water-soluble Inorganic Chemicals – acids, toxic metals
Inorganic Plant Nutrients – nitrogen and phosphorus
Organic Chemicals – oil, pesticides, detergents
Sediment or Suspended Material – erosion, soil
Water-soluble Radioactive Isotopes – radon uranium
Heat – electric and nuclear power plants
Genetic Pollution
1) Disease-causing Agents – pathogens
Infectious Agents: pathogenic organisms. Water-borne diseases include typhoid,
cholera, bacterial and amoebic dysentery, polio, infectious hepatitis, guinea worm
and schistosomiasis. Due to lack of sanitation.
Analyze coliform bacteria (E. coli). Presume if coliform bacteria are present,
infectious pathogens are also present.
Waterborne Bacteria
• Disease symptoms usually are explosive emissions from either end of the
digestive tract
Dr. Nabaa Shakir Hadi
Environment Protection (I)
Escherichia coli
2014-2015
Vibrio sp.
Waterborne Protozoans
• Disease symptoms are usually explosive emissions from either end of the
digestive tract
*P. Darben
Giardia sp.*
Guinea Worm Disease
• People have suffered from Guinea Worms for centuries – the “fiery serpent”
was mentioned in the bible
• People are infected by drinking water that contain the larvae in a tiny
freshwater crustacean called Cyclops
• A year later, larvae mature into 3 feet worms that emerge through skin
blisters
• This is such a painful process that men and women can’t work, children
can’t attend school
The Guinea Worm grows down the leg and its sex organs appear at the ankle or
on the foot usually, bursting when it senses water, releasing ova
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
2) Oxygen Demanding Agents – organic waste: manure
Biological Oxygen Demand (BOD)
• BOD: Oxygen is removed from water when organic matter is consumed by
bacteria.
• Low oxygen conditions may kill fish and other organisms.
Sources of organic matter
• Natural inputs-- bogs, swamps, leaf fall, and vegetation aligning waterways.
• Human inputs-- pulp and paper mills, meat-packing plants, food processing
industries, and wastewater treatment plants.
• Nonpoint inputs-- runoff from urban areas, agricultural areas, and feedlots.
3)Water-soluble Inorganic Chemicals – acids, toxic metals
Heavy Metals
• Metallic elements having a density greater than 5 g/cm3
• Most are extremely toxic
– Water soluble
– Readily absorbed into plant or animal tissue
• Bioconcentrate
– Combine with biomolecules
• Proteins
• Nucleic acids
Sources of Heavy Metals
• Natural
–Redistributed by geologic and biologic cycles
• Industrial
• Burning of fossil fuels
• Environmental pollution
Acid Rain
• Broad term used to describe several ways that acids fall out of the
atmosphere
Wet and Dry Acid Rain
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
• Wet deposition refers to acidic rain, fog, and snow.
• Dry deposition refers to acidic gases and particles.
Causes of Acid Rain
• Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of
acid rain.
• In the US, about 2/3 of all SO2 and 1/4 of all NOx comes from electric power
generation that relies on burning fossil fuels like coal.
Formation of Acid Rain
• Gases react in the atmosphere with water, oxygen, and other chemicals to
form a mild solution of sulfuric acid and nitric acid.
Effects on Wildlife
• Generally, the young of most species are more sensitive to environmental
conditions than adults
• At pH 5, most fish eggs cannot hatch
• At lower pH levels, some adult fish die
• Some acid lakes have no fish
Nutrients
• Acidic water dissolves the nutrients and helpful minerals in the soil and then
washes them away before trees and other plants can use them to grow.
• Acid rain also causes the release of substances that are toxic to trees and
plants, such as aluminum, into the soil.
4) Inorganic Plant Nutrients – nitrogen and phosphorus
Selected Pollutants: Nutrients
Phosphorus and nitrogen are the major concerns Sources:
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Human, animal (e.g., Hog Farms), and industrial waste
Storm water
Soil erosion
Excessive use of fertilizers for crops, lawns, and home
Selected Pollutants: Nutrients
High nutrient concentrations can cause Eutrophication of water
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Eutrophication is characterized by rapid increase in plant life. An example is the
algae bloom shown here.
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Algae blooms block sunlight so plants below die.
Decomposition of dead plants consumes oxygen.
Low oxygen conditions may kill fish etc.
Aesthetics (color, clarity, smell)
Uptake and release of toxics
5) Organic Chemicals – oil, pesticides, detergents
Biological Magnification
Concentrations increase at increasing levels in the food chain – PCBs, DDT, etc.
Organic Pollutants: Dioxin, PCB, DDT (Chlorinated)
Dioxin: stable; slow to degrade
Generated from: Burning wood, coal, oil, household trash, and chlorine bleaching
of pulp and paper
Accumulates in fat of animals →biomagnification
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Causes: Cancer
Weakened immune response
PCBs: non-flammable; not dissolved in water; high boiling points; does not
conduct electricity well. So used for transformers and capacitors.
More than one billion pounds of PCBs have been made.
Accumulates in fat of animals → biomagnification
Causes: Cancer
Hormonal and reproductive disruptions
Decrease cognitive abilities (dopamine)
DDT : insecticide; stable and slow to degrade.
Benefits: Controlled spread of malaria;
Provided crop protection
Problems with DDT: DDT is not metabolized very rapidly by animals; instead, it
is deposited and stored in the fatty tissues → biomagnification
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Problems with DDT: stable and slow to degrade
- Toxic to Fish
- Increased mortality in birds: calcium decreased in egg shells
- Estrogen mimic in Vertebrates: feminizes males - lower
 sperm count; alters behavior
- Human Health
 decreased mental function
 male infertility
 cancer
6) Sediment or Suspended Material – erosion, soil
Erosion
Sediment (clay, silt) is the #1 source of water pollution. Bare soil easily washes
into storm drains and streams, clouding the water and suffocating aquatic life.
• Never leave soil exposed! Place straw over newly seeded areas.
• Cover your garden during winter months.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
• Sod, seed, grow plants, or build terraces on slopes.
• Rock gardens can also be effective for slowing the flow of water and
minimizing erosion.
Negative Effects of Sediment Loading
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Destruction of spawning beds
Adsorption and transport of other pollutants
Reduced light penetration, aquatic vegetation
Greater nutrients loadings, oxygen demand
Interference with navigation, flood control, recreation, industry
7)Water-soluble Radioactive Isotopes – radon uranium
China Syndrome
• In a complete reactor meltdown, the extremely hot (about 2700º Celsius)
molten uranium fuel rods would melt through the bottom of the reactor and
actually sink about 50 feet into the earth beneath the power plant
• Molten uranium would react with groundwater, producing large explosions
of radioactive steam and debris that would affect nearby towns and
population centers
8)Heat – electric and nuclear power plants
Industrial Water Pollution
• Thermal Pollution occurs when water is withdrawn, used for cooling
purposes, and then heated water is returned to its original source
• An increase in temperature, even a few degrees, may significantly alter some
aquatic ecosystems
Waste Heat
• On national scale, industrial cooling waters is a first-order source of heat
• Electric power generation uses 80% of cooling waters
• Past experience has indicated that thermal pollution has not multiplied
as fast as power generation because of improvements in thermal plant
efficiency and development of hydropower
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
• Nuclear plants - waste even higher proportion of heat than fossil-fuel
plants
9)Genetic Pollution
Hydrilla: Non-native Aquatic Plant
• Dense mats alter water quality
– raising pH
– decreasing oxygen under the mats
– increasing temperature
– stagnant water
– good breeding grounds for mosquitoes
• Hydrilla will grow with less light and fewer
nutrients, and can out compete other native and non-native plant
• Fish populations are negatively affected if hydrilla exceeds 30-40%
coverage of the lake
• Hydrilla video clip
Oxygen-Demanding Wastes: Oxygen dissolved in water is indicator of water
quality. 6 ppm O2 or more supports desirable aquatic life.
BOD(mg/L): Biochemical oxygen demand: measures the amount of dissolved
oxygen consumed by aquatic microorganisms. Sewage, paper pulp, or food wastes
can cause an Oxygen sag, where few fish survive.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
A simplified representation of decomposition is given by the following:
Aerobic Decomposition
𝑂𝑟𝑔𝑎𝑛𝑖𝑐 𝑚𝑎𝑡𝑡𝑒𝑟 + 𝑂2
𝑀𝑖𝑐𝑟𝑜𝑜𝑟𝑔𝑎𝑛𝑖𝑠𝑚𝑠
→
CO2 + H2 O + New cells + Stable products(NO3 , PO4 , SO4 , … )
Anaerobic Decomposition
𝑂𝑟𝑔𝑎𝑛𝑖𝑐 𝑚𝑎𝑡𝑡𝑒𝑟
𝑀𝑖𝑐𝑟𝑜𝑜𝑟𝑔𝑎𝑛𝑖𝑠𝑚𝑠
→
CO2 + H2 O + New cells + Unstable products(H2 S, NH3 , CH4 , … )
BOD and Eutrophication: rapid succession in a body of water because of an
increase in biological productivity.
Oligotrophic: lakes and rivers have clear water and low biological productivity).
Five-day BOD Test:
BOD is the amount of dissolved oxygen consumed by microorganisms during the
biochemical oxidation of organic and inorganic matter to carbon dioxide
5-day BOD test :
BOD5 =
DOi − DOf
… … … … … … … … … … … … … … … … … … … … … . (2)
P
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Where:
DOi = the initial dissolved oxygen (DO) of the diluted wastewater
DOf = the final DO of the diluted wastewater,5 days later
P = the dilution fraction =
volume of wastewater
volume of wastewater plus dilution water
A standard BOD bottle holds 300mL, so P is just the volume of wastewater divided
by 300mL.
In such cases, to find the BOD of the waste itself, it is necessary to subtract
the oxygen demand caused by the seed from the demand in the mixed sample of
waste and dilution water.
The oxygen demand of the waste itself (BODw)can then be determined as:
BODw =
BODm − BODd (1 − P)
… … … … … … … … … … … … … … … . . (3)
P
BODm = DOi − DOf
𝑎𝑛𝑑 BODd = Bi − Bf
Where:
Bi = initial DO in the seeded dilution water (blank)
Bf = final DO in the seeded dilution water
Our final expression for the BOD of the waste itself is thus
BODw =
(DOi − DOf ) − (Bi − Bf )(1 − P)
… … … … … … … … … … … . (4)
P
Example 1
A test bottle containing just seeded dilution water has its DO level drop by 1.0
mg/L in a five-day test. A 300mL BOD bottle filled with 15 mL of wastewater and
the rest seeded dilution water (sometimes expressed as a dilution of 1:20)
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
experiences a drop of 7.2 mg/L in the same time period. What would be the fiveday BOD of the waste?
Solution: The dilution factor P is
P = 15⁄300 = 0.05
Using (4), the five-day BOD of the waste would be
BODw =
7.2 − 1.0(1 − 0.05)
= 125 mg/L
0.05
Modeling BOD as a first-order Reaction
dLt
= −−kLt … … … … … … … … … … … … … … … … … … … … … … … … (5)
dt
Where k= the BOD reaction constant (time-1).
The solution to (5) is
Lt = L0 e−kt … … … … … … … … … … … … … … … … … … … … … … … … (6)
Where:
L0 is the ultimate carbonaceous oxygen demand.
The ultimate carbonaceous oxygen demand is the sum of the amount of oxygen
already consumed by the waste in the first t days (BODt), plus the amount of
oxygen remaining to be consumed after time t. That is,
Lo = BODt + Lt … … … … … … … … … … … … … … … … … … … … … … (7)
Combining (6) and (7) gives us
BODt = Lo (1 − e−kt ) … … … … … … … … … … … … … … … … … … … … (8)
BODt = Lo (1 − 10−kt ) … … … … … … … … … … … … … … … … … … … (9)
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Where upper case K is the reaction rate coefficient to base 10. It is easy to show
that
k = Kln10 = 2.303K … … … … … … … … … … … … … … … … … … … … (10)
Two equivalent ways to describe the time dependence of organic matter in a flask.
Idealized carbonaceous oxygen demand:(a)The BOD remaining as a function of
time ,and(b)the oxygen already consumed as a function of time.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
The BOD Reaction Rate Constant k
Table 2 Typical values for the BOD rate constant k at 20 °C
Sample
k(day-1)a
K(day-1)b
Raw sewage
0.35-0.70
0.15-0.30
Well-treated sewage
0.12-0.23
0.05-0.10
Polluted river water
0.12-0.23
0.05-0.10
a
Lowercase k reaction rates to the base e.
b
Uppercase K reaction rates to the base 10.
k t = k 20 θ(T−20) … … … … … … … … … … … … … … … … … … … … … … (11)
where k 20 is the reaction rate constant at the standard 20 °C laboratory reference
temperature, and kT is the reaction rate at a different temperature T (expressed in
°C). The most commonly used value for θ is 1.047, and although θ is somewhat
temperature dependent, that single value will suffice for our purposes.
Nitrification
Nitrogen is the critical element required for protein synthesis and, hence, is
essential to life. When living things die or excrete waste products, nitrogen that
was tied to complex organic molecules is converted to ammonia by bacteria and
fungi. Then, in aerobic environments, nitrite bacteria (Nitrosomonas) convert
ammonia to nitrite (NO2- ), and nitrate bacteria (Nitrobacter) convert nitrite to
nitrate (NO3- ). This process, called nitrification, can be represented with the
following two reactions:
Nitrosomonas
2NH3 + 3O2 →
Nitrobacter
2NO−
2 + O2 →
+
2NO−
2 + 2H + 2H2 O … … … … … . (12)
2NO−
3 … … … … … … … … … … … … … … (13)
This conversion of ammonia to nitrate requires oxygen, so nitrification exerts
its own oxygen demand. Thus, we have The oxygen needed to oxidize organic
carbon to carbon dioxide is called the carbonaceous oxygen demand (CBOD),
while the oxygen needed to convert ammonia to nitrate is called the nitrogenous
oxygen demand (NBOD).
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Illustrating the carbonaceous and nitrogenous biochemical oxygen demand. Total
BOD is the sum of the two.
Example 2
Some domestic wastewater has 30 mg/L of nitrogen either in the form of
organic nitrogen or ammonia. Assuming that very few new cells of bacteria are
formed during the nitrification of the waste (that is, the oxygen demand can be
found from a simple stoichiometric analysis of the nitrification reactions given
above),find
a. The ultimate nitrogenous oxygen demand
b. The ratio of the ultimate NBOD to the concentration of nitrogen in the
waste.
Solution
a. Combining the two nitrification reactions (12) and (13) yields
+
NH3 + 2O2 → NO−
3 + H + H2 O
The molecular weight of NH3 is 17, and the molecular weight of O2 is 32. The
foregoing reaction indicates that one g-mol of NH3 (17g) requires two g-mole of
O2 (2×32=64 g). since 17 g of NH3 contains 14g of N, and the concentration of N
is 30 mg/L, we can find the final, or ultimate, NBOD:
Dr. Nabaa Shakir Hadi
NBOD = 30 mg
Environment Protection (I)
2014-2015
N 17g NH3
64gO2
×
×
= 137 mg O2 ⁄L
L
14gN
17gNH3
b. The oxygen demand due to nitrification divided by the concentration of
nitrogen in the waste is
137 mg O2 ⁄L
= 4.57 mg O2 ⁄mg N
30 mg N⁄L
The total concentration of organic nitrogen and ammonia in wastewater is
known as the total Kjeldahl nitrogen, or TKN. As was demonstrated in the
preceding example, the nitrogenous oxygen demand can be estimated by
multiplying the TKN by 4.57. This is a result work noting:
Ultimate NBOD ≈ 4.57 × TKN … … … … … … … … … … … … … … … … (14)
Since untreated domestic wastewaters typically contain approximately 15-50
mg/L of TKN, the oxygen demand caused by nitrification is considerable, ranging
from roughly 70 to 230 mg/L. For comparison, typical raw sewage has an ultimate
carbonaceous oxygen demand of 250-350 mg/L.
The Effect of Oxygen-Demanding Wastes on Rivers
Deoxygenation
The rate of deoxygenation at any point in the river is assumed to be
proportional to the BOD remaining at that point. That is,
Rate of deoxygenation = k d Lt … … … … … … … … … … … … … … … (15)
Where:
k d = the deoxygenation rate constant (day-1)
Lt = the BOD remaining t(days) after the wastes enter the river, (mg/L)
Substituting(6), which gives BOD remaining after time t, into (15)gives
Rate of deoxygenation = k d L0 e−kd t … … … … … … … … … … … … … (16)
where L0 is the BOD of the mixture of stream water and wastewater at the point
of discharge. Assuming complete and instantaneous mixing,
Dr. Nabaa Shakir Hadi
L0 =
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2014-2015
Q w Lw + Q r Lr
… … … … … … … … … … … … … … … … … … … … … (17)
Qw + Qr
Where:
L0 = ultimate BOD of the mixture of streamwater and wastewater (mg/L)
Lr = ultimate BOD of the river just upstream of the point of discharge (mg/L)
Lw = Ultimate BOD of the wastewater (mg/L)
Q r = volumetric flow rate of the river just upstream of the discharge point (m3/s)
Q w = volumetric flow rate of wastewater (m3/s)
Reaeration
Rate of reaeration = k t D … … … … … … … … … … … … … … … … . (18)
Where:
k t = reaeration constant (time-1)
D = dissolved oxygen deficit = (𝐷𝑂𝑠 − 𝐷𝑂) … … … … … … … … … (19)
𝐷𝑂𝑠 = saturated value of dissolved oxygen
𝐷𝑂 = actual dissolved oxygen at a given location downstream
Many attemps have been made empirically to relate key stream parameters to
the reaeration constant, with one of the most commonly used formulations being
the following (O'Connor and Dobbins,1958):
3.9u1⁄2
kr =
… … … … … … … … … … … … … … … … … … … … … … … (20)
H 3⁄2
Where:
k r = reaeration coefficient at 20° 𝐶 (day-1)
𝑢 = average stream velocity (m⁄s)
H = average stream depth (m)
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Table 3 Solubility of Oxygen in Water (mg/L)at 1 atm pressure
Chloride concentration in water (mg/L)
0
5000
10,000
15,000
Temperature (°C)
0
14.62
13.73
12.89
12.10
5
12.77
12.02
11.32
10.66
10
11.29
10.66
10.06
9.49
15
10.08
9.54
9.03
8.54
20
9.09
8.62
8.17
7.75
25
8.26
7.85
7.46
7.08
30
7.56
7.19
6.85
6.51
we can calculate the initial deficit of the polluted river using a weighted average
based on their individual concentrations of dissolved oxygen:
D0 = DOs −
Q w DOw + Q r DOr
… … … … … … … … … … … … … … … … (21)
Qw + Qr
Where:
D0 = initial oxygen deficit of the mixture of river and wastewater
DOs = saturated value of DO in water at the temperature of the river
DOw =DO in the wastewater
DOr =DO in the river just upstream of the wastewater discharge point
The Oxygen Sag Curve
Combining the two equations (15) and (18) yields the following expression for
the rate of increase of the oxygen deficit:
Rate of increase of the deficit = Rate of deoxygenation–Rate of oxygenation
dD
= k d L0 e−kd t − k t D … … … … … … … … … … … … … … … … … (22)
dt
Which has the solution
D=
k d L0
(e−kd t − e−krt ) + D0 e−krt … … … … … … … … . . … (23)
kr − kd
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Environment Protection (I)
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Since the deficit D is the difference between the saturation value of dissolved
oxygen DOs and the actual value DO, we can write the equation for the DO as
DO = DOs − [
kd L0
kr −kd
(e−kd t − e−krt ) + D0 e−krt ] … … … … . … (24)
𝐷 = (𝑘𝑑 𝐿0 𝑡 + 𝐷0 )𝑒 −𝑘𝑑𝑡 … … … … … … … … … … … … … … … … (25)
If the stream has a constant cross-sectional area and is traveling at a speed 𝑢,
then time and distance downstream are related by
𝑥 = 𝑢𝑡 … … … … … … … … … … … … … … … … … … … … … … … . . (26)
Where:
𝑥 = distance downstream
𝑢 =stream speed
𝑡 =elapsed time between discharge point and distance x downstream
Equation (1.27)can be rewritten as
𝐷=
𝑘𝑑 𝐿0
(𝑒 −𝑘𝑑𝑥⁄𝑢 − 𝑒 −𝑘𝑟 𝑥⁄𝑢 ) + 𝐷0 𝑒 −𝑘𝑟 𝑥⁄𝑢 … … … … … (27)
𝑘𝑟 − 𝑘𝑑
tc =
1
kr
D0 (k r − k d )
ln { [1 −
]} … … … … … … … … . (28)
kr − kd
kd
k d L0
Streeter-Phelps oxygen sag curve.
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Environment Protection (I)
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while the rate of deoxygenation exceeds the rate of reaeration the DO in the river
drops. At the critical point those rates are equal. Beyond the critical point,
reaeration exceeds decomposition, the DO curve climbs toward saturation, and the
river recovers.
Example 3
Just below the point where a continuous discharge of pollution mixes with a
river, the BOD is 10.9 mg/L and DO is 7.6 mg/L. the river and waste mixture has a
temperature at 20° C , a deoxygenation constant 𝑘𝑑 of 0.20/day, an average flow
speed of 0.30m/s. and an average depth of 3.0m.
a. Find the time and distance downstream at which the oxygen deficit is a
maximum.
b. Find the minimum value of DO.
Solution From Table3, the saturation value of DO at 20° C is 9.1 mg/L, so the
initial deficit is
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D0 = 9.1 mg⁄L − 7.6 mg⁄L = 1.5 mg⁄L
To estimate the reaeration constant, we can use the O'Connor and Dobbins
relationship given in (1.24):
3.9u1⁄2 3.9(0.30)1⁄2
kr =
=
= 0.41/day
(3.0)3⁄2
H 3⁄2
a. Using (1.32), we can find the time at which the deficit is a maximum:
1
kr
D0 (k r − k d )
tc =
ln { [1 −
]}
kr − kd
kd
k d L0
1
0.41
1.5(0.41 − 0.20)
=
ln {
[1 −
]} = 2.67 days
(0.41 − 0.20)
0.20
0.20 × 10.9
So the critical distance downstream would be
xc = ut c = 0.30 m⁄s × 3600 s⁄hr × 24 hr⁄d × 2.67d = 69,300m = 69.3km
Which is about 43 miles
b. The maximum deficit can be found from(1.27):
D=
kd L0
0.20×10.9
(e−kdt − e−krt ) + D0 e−krt = (0.41−0.20) (e−0.20×2.67 − e−0.41×2.67 ) +
kr −kd
−0.41×2.67
1.5e
= 3.1 mg/L
So the minimum value of DO will be the saturation value minus this maximum
deficit:
DOmin = (9.1 − 3.1) mg⁄L = 6.0 mg⁄L
Example 4
A waste water effluent of 560L/ses with a BOD=50mg/L, DO=3mg/L, and
temperature of 23℃ enters a river where the flow is 2.8 m3/sec with a BOD of
4mg/L DO of 8.2 mg/L and temperature of 17℃ from laboratory BOD testing, kd
of the waste is 0.1 per day at 20℃, the river downstream has an average velocity of
0.18m/sec and depth of 1.2m. calculate the minimum dissolved oxygen level and
its distance downstream by using the oxygen sag equation?
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Example 5
River discharge( 10m3/sec) and BOD Which equals (2mg/L) Pour the waste
industry No(1) With a discharge droppings (1m3/sec) and BOD This waste is (
150mg/L). And on the path 2days from the mouth of the first industry located
estuary Industry No(2) Which a discharged (1m3/sec) and reach the BOD
(13mg/L). Required to find the value of the lowest level of oxygen in the river If
the waste industries and river saturated with oxygen (9.2mg/L) , The constant
value decomposition of waste (k1=0.1) per day and constant ventilation river
(k2=0.3) per day, respectively.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
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CHAPTER 3
Water and Wastewater Treatment
Water Treatment Stages
Depending on the type of treatment plant and the quality of raw water, treatment
generally proceeds in the following sequence of stages:
1. Screening
2. Aeration
3. pH correction
4. Coagulation and flocculation
5. Sedimentation
6. Pre-chlorination and dechlorination
7. Filtration
8. Disinfection
9. pH adjustment
Municipal Water Purification Plant
Initial Stages
• Screening : the removal of any coarse floating objects, weeds, etc. from the
water.
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• Aeration : dissolving oxygen into the water to remove smell and taste,
promote helpful bacteria to grow, and precipitate nuisance metals like iron
and manganese.
• pH correction : preparing for coagulation and to help precipitate metals.
Major Clean Up
• Coagulation and flocculation : causes the agglomeration and sedimentation
of suspended solid particles through the addition of a coagulating agent
(usually aluminum sulfate and/or iron sulfate) to the raw water along with a
polymer to help form a floc.
• Sedimentation : Floc settles out and is scraped and vacuumed off the bed of
large sedimentation tanks. Clarified water drains out of the top of these tanks
in a giant decanting process.
• Pre-chlorination and dechlorination : mostly to kill algae that would
otherwise grow and clog the water filters. Also kills much of the remaining
unprotected bacteria.
Coagulation
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Sedimentation
Filtration
Final Touches
• Disinfection : water completely free of suspended sediment is treated with a
powerful oxidizing agent usually chlorine, chlorine then ammonia
(chloramine), or ozone.
– A residual disinfectant is left in the water to prevent reinfection.
– Chlorine can form harmful byproducts and has suspected links to
stomach cancer and miscarriages.
– Many agencies now residually disinfect with Chloramine.
• pH adjustment : so that treated water leaves the plant in the desired range of
6.5 to 8.5 pH units.
Additional Steps
• Heavy metal removal: most treatment plants do not have special stages for
metals but rely on oxygenation, coagulation and ion exchange in filters to
remove them. If metals persist, additional treatment would be needed
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• Troublesome organics: Activated carbon filters are required where soluble
organic constituents are present because many will pass straight through
standard plants, e.g. pesticides, phenols, MTBE and so forth
Adsorption
Sewage or Wastewater Treatment
• Sewage or wastewater is composed of sewage or wastewater from:
– Domestic used water and toilet wastes
– Rainwater
– Industrial effluent (Toxic industrial water is pretreated)
– Livestock wastes
** microbes degrade organic compounds
** elimination of pathogens occurs
Wastewater:
is simply that part of the water supply to the community or to the industry which
has been used for different purposes and has been mixed with solids either
suspended or dissolved.
Wastewater is 99.9% water and 0.1% solids. The main task in treating the
wastewater is simply to remove most or all of this 0.1% of solids.
Wastewater Treatment:
Types of treatment systems include: Septic Tanks or Wastewater Treatment
Plants (WWTPs).
• Septic Tanks typically treat small volumes of waste (e.g., from a single
household, small commercial/industral)
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• WWTPs typically treat larger volumes of municipal or industrial waste.
Decentralized Alternatives
• In rural areas or in particular urban communities in the U.S., human
wastewater will be treated through individual septic tank systems (pumped
or leachfield varieties)
• Wastewater is filtered, microorganisms killed and chemicals adsorbed and/or
diluted in its passage through the soils and rocks of the leachfield
• In developing countries, urban wastewater is seldom treated and instead
flows raw through collectors to receiving water bodies (like in the US 100
years ago)
• The solution for many developing nations is centralized oxidation lagoon
systems (but this needs space) or the use of individual ventilated pit-latrines,
especially for shanty towns and rural villages
Home Septic Systems:
 do not use Chlorine
 Do use settling tank to settle organic solids
 Lets waste water percolate into the soil bacterial decomposition
Septic Tanks
• Approx. 22 million systems in operation ( 30% of US population)
• Suitability determined by soil type, depth to water table, depth to bedrock
and topography
• Commonly fail due to poor soil drainage
• Potential contaminants: bacteria, heavy metals, nutrients, synthetic organic
chemicals (e.g. benzene)
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Municipal wastewater treatment plant : is engineered to reduce area/volume
normally required in nature to remove nutrients and pathogens from wastewater
Wastewater Treatment system:
 Primary treatment: physical separation of solids
 Secondary treatment: Aeration tank: biodegradation
 Tertiary treatment: remove phosphates/nitrates lagoon/marsh or trickling
filter.
 Bioremediation: use of organisms to remove water pollutants
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Typical wastewater treatment plant

Primary Treatment : Separation of large debris following sedimentation
Gravel, sand, twigs. Leaves (Physical removal of large debris).
• Bar Screen (First treatment step)
• Grit Chamber (Second treatment step)
• Primary clarifiers (Third treatment step)
Primary SettlingTank
Sludge
• Anaerobic sludge digestor
• To land application
Primary Clarifiers:
• Separate liquids from solids
• Skimmer removes grease at the surface and sends it to anaerobic digestor

Secondary Treatment : Remaining suspended solids are decomposed and
number of pathogens are reduced (Microbiological conversion of organic-C to CO2
and H2O).
• Aeration tank or Trickling filter
• Final settling tank or clarifier
• Anaerobic sludge digester
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Block diagram of an activated sludge system
Trickling filter
Activated Sludge Process (aerobic microbial metabolism)
•
•
•
•
Mixed Liquor Suspended Solids (MLSS)
Air is pumped through the wastewater
Sludge is removed from the bottom and sent to the anaerobic sludge digestor
Some of the sludge is used to inoculate the fresh, incoming wastewater entering the
aeration tank
Q × BOD
Food/Microbes Ratio=
MLSS ×V
Q = flow rate of sewage in millions of gallons per day (MGD)
MLSS is in mg/l
V is volume of aeration tank (gallons)
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Environment Protection (I)
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Food/Microbe Ratio
•
•
•
•
The higher the waste rate, the higher the ratio.
0.2-0.5 lb/BOD5/day/lb MLSS is normal
A low ratio means that the microbes are starving.
Computers keep track of properties of sewage and operating parameters of
wastewater treatment process
Important Operating Parameters
• Organic loading rate
• Oxygen supply
• Control and operation of the final settling tank
Functions:
• Clarification
• Thickening
Sludge settleability is determined by sludge volume index (SVI)
Sludge volume index (SVI): The volume in milliliters occupied by one gram of
activated sludge which has settled for 30 min.
SVI =
mLs Settled in 30 min
MLSS Conc,grams/L
SVI (ml/g)=
=
mLs Settled
MLSS,mg⁄L
1000
V ×1000
MLSS
where V is volume of settled sludge after 30 min
CALCULATION OF POUNDS
Organic Load= Pounds of Organics (BOD)
Coming into Aeration Tank
Pounds =Conc. × Flow (or Volume) × 8.34 Lbs/gallon
Conc. = Concentration of stuff in the water
Flow = Quantity of water the stuff is in
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8.34 Lbs/gallon = Weight of the water
Pounds =Conc. × Flow (or Volume) × 8.34 Lbs/gallon
Flow (Volume) and Concentration must be expressed in specific units.
Concentration must be expressed as parts per million parts:
Concentration is usually reported as milligrams per liter. This unit is equivalent to
ppm.
1 mg
1 mg
1 mg
=
=
= ppm
liter 1000 grams 1000000 mg
ppm =
Parts
Lbs
=
Mil Parts M Lbs
Flow or Volume must be expressed as millions of gallons:
gallon
= MG
1000000 gal⁄MG
i.e.) A tank contains 1,125,000 gallons of water.
How many million gallons are there?
1,125,000 gal
= 1.125 MG
1000000 gal⁄MG
When Flow is expressed as MGD and concentration is in ppm, the units cancel to
leave Pounds/Day.
Lbs/Day = Conc. × Flow × 8.34 Lbs/gallon
Lbs⁄Day =
Example 1
Lbs
M gal Lbs
×
×
M Lbs Day
gal
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Environment Protection (I)
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How many pounds of suspended solids leave a facility each day if the flow rate is
150,000 gal/day and the concentration of suspended solids is 25 mg/L?
Solution
Lbs/Day = Conc.( mg/L) × Flow(MGD) × 8.34 Lbs/gallon
Lbs/Day = 25 ( mg/L) ×
1,125,000 gal
1000000 gal⁄MG
× 8.34 Lbs/gallon
= 25 x 0.15 x 8.34
= 31 Lbs/day
Need to Balance Organic Load (lbs BOD) With Number of Active Organisms
in Treatment System
F
Ratio Food to Microorganism F: M or ( )
M
How Much Food ?
Primary Effluent BOD
Lbs/D BOD = FLOW (MGD) × 8.34 Lbs/Gal × P.E. BOD (mg/L)
F = Pounds BOD (Coming into Aeration Tank)
How is M (Microorganisms) measured?
Mixed Liquor Suspended Solids (MLSS) or Mixed Liquor Volatile Suspended
Solids (MLVSS)
M = Pounds MLSS or MLVSS (In Aeration Tank)
Lbs MLVSS =Volume Aeration Tank, MG × MLVSS, mg/L× 8.34 Lbs/gal
Aeration Tank Volume (MG):
L (ft) × W (ft) × SWD (ft) = Volume (ft3)
ft3 × 7.48 gal/ft3 = gallons
gallons / 1,000,000 = million gallons (MG)
Example Calculation2:
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Environment Protection (I)
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A. Calculate the volume in million gallons of an aeration tank that is 120 ft long,
35 ft wide, with a SWD of 15 ft.
V=L×W×D
V = 120 ft × 35 ft×15 ft = 63,000 ft3
63,000 ft3 × 7.48 gal/ ft3 = 471,240 gallons
471,240 gallons / 1,000,000 = 0.471 MG
B. The average BOD load on this aeration tank is 1954 lbs/day. Calculate the
organic loading in lbs/day/1000ft3.
1954 lbs/day
× 1000 = 31.0 lbs⁄day⁄1000 ft 3
63,000 ft 3
Example Problem3:
Calculate the pounds of volatile solids in an aeration tank that has a volume of
0.471 MG and the concentration of volatile suspended solids is 1700 mg/L.
Lbs = 0.471 MG×1700 mg/L × 8.34 lbs/gal = 6678 lbs MLVSS
Example Problem4:
The 7-day moving average BOD is 2002 lbs and the mixed liquor volatile
suspended solids is 6681 pounds. Calculate the F/M ratio of the process.
F
2002 lbs BOD
=
= 0.30
M 6681 lbs MLVSS
Food to Microorganism Ratio Calculations:
Typical Range:
Conventional Activated Sludge F:M→0.25 - 0.45
Extended Aeration Activated Sludge F:M→ 0.05 - 0.15
F/M Ratio is Used to Determine the Lbs of MLVSS Needed at a Particular
Loading Rate (FOR DAILY USE)
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F⁄ M =
F
F⁄M
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Lbs BOD
lbs MLVSS
=M (Lbs MLVSS)
suppose F/M of 0.30 is desired and BOD loading is 1200 lbs/day
𝐹
𝑀
= 0.30
→
F
F⁄M
=M (Lbs MLVSS)
F
1200lbs
=M →
= 4000 lbs MLVSS
0.30
0.30
If we Know the Pounds of MLVSS Needed and the Volume of the Aeration Tank
We Can Calculate MLVSS, mg/L.
Calculate the MLVSS, mg/L given an Aeration Tank Volume of 0.20 MG.
4000 lbs = 0.20 MG × 8.34 lbs/ gal × ? mg/L
4000 lbs
0.20 MG × 8.34 lbs/ gal
=2398 mg/L
Example Problem5:
Problem A:
How many pounds of MLVSS should be maintained in an aeration tank with a
volume of 0.105 MG receiving primary effluent BOD of 630 lbs/d ? The desired
F:M is 0.3.
Problem B:
What will be the MLVSS concentration in mg/L ?

Tertiary treatment : Involves a series of steps to further reduce organic
concentration, turbidity, N, P, metals, and pathogens (Inactivate pathogens, remove,
N, P, toxins from water before release to environment)
• Process used when water is to be used for irrigation, recreation, drinking
water
• Involves
 Filtration
• Very effective in removing Crytosporidium and Giardia
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•
90% removal of enteric bacteria and viruses
 Coagulation (iron and aluminum salts, pH>11
• 99% removal of enteric viruses
 Activated carbon adsorption
 Additional disinfection
Nitrogen Removal During Activated Sludge Process:
• Encourage nitrification followed by denitrification
• Growth rate of nitrifying bacteria must be greater than the heterotrophic
bacteria in system
– Nitrification requires a long (>4 days) sludge retention time
Phosphorus Removal:
• Uptake of phosphate by microbes during aerobic stage followed by release
of phosphate during anaerobic stage

•
•
•
•
Disinfection
Addition of chlorine
24-h contact time needed for chlorine to kill bacteria in water before release
into the environment
– Only in summer in Bozeman
– Assume low water temps in receiving water kills pathogens
Sulfur dioxide is added to water to remove chlorine after sufficient contact
time to kill pathogens before discharge of water into environment
In future, uv-treatment to kill microbes will replace chlorine
– Ultraviolet radiation of water allows less chlorine to be used, and
reduces contact time.
Removal Efficiency
The effectiveness of removal of TSS,BOD and COD was calculated using the
following formula:
% Removal efficiency of P=( Pinf - Peff ) / Pin ×100
Where,P is the selected parameter, Pinf is the mean influent and Peff is the
mean effluent.
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Environment Protection (I)
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CHAPTER 4
Waste Heat
Thermal power plants : account for about 80% of global electricity generation are
approximately as follows:
coal 40%
natural gas 20%
nuclear and hydro 16%
oil 6%
solar and wind 2%
The Role of Cooling in Fossil and Nuclear Power Plants:
Generally, fossil and nuclear power plants use water for heat transfer in two ways:
 Internal Energy Transfer. To convey steam heat created by the energy source
- either the coal furnace or the reactor core - to power an electricitygenerating turbine; and
 Cooling and Surplus Heat Discharge. To cool and condense the after-turbine
steam and then discharge surplus heat from the steam circuit to the
environment.
What drives water use in thermal power plants?
1.The type of cooling system used
2.The efficiency of the power plant and not that much the type of power plant
Thermal Power Plants
All the waste heat (“loss”) has to be rejected somehow to the environment. The
vast majority of this heat is rejected to the environment through cooling systems.
Example of Efficiencies:
 Natural Gas Combined Cycle: ~50%
 Super Critical Pulverized Coal: ~39%
 Subcritical Pulverized Coal: ~36%
 Nuclear: ~33%
 Solar Thermal (Rankine Cycle) : ~32%
 Old coal power plants: as low as 20%!
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Type of Cooling System
1.Once-through cooling
2. Evaporative cooling (Recirculating)
3. Dry or hybrid cooling
Once-through cooling: the cooling water passes through heat exchange equipment
only once. The mineral content of the cooling water remains practically unchanged
as it passes through the system. Because large volumes of cooling water are used,
these systems are used less often than recirculating systems. Seasonal temperature
variation of the incoming water can create operational problems. Temperature
pollution of lakes and rivers by system discharge is an environmental concern.
Once-through cooling
Evaporative cooling: are the most widely used industrial cooling design. These
systems consist of pumps, heat exchangers, and a cooling tower. The pumps keep
the water recirculating through heat exchangers. It picks up heat and moves it to
the cooling tower where the heat is released from the water through evaporation.
Because of evaporation, the water in open recirculating systems undergoes changes
in its basic chemistry. The dissolved and suspended solids in the water become
more concentrated.
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Evaporative cooling
Dry or hybrid cooling: use the same cooling water repeatedly in a continuous
cycle. First, the water absorbs heat from process fluids, and then releases it in
another heat exchanger. In these systems, an evaporative cooling tower is not
included. Often used for critical cooling applications or when water temperature
below ambient is required, as in a chilled water system.
Dry or hybrid cooling
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Environment Protection (I)
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CHAPTER 5
Air Pollution
Atmosphere as a Resource:
 Atmospheric Composition
• Nitrogen 78.08%
• Oxygen 20.95%
• Argon 0.93%
• Carbon dioxide 0.04%
 Ecosystem services
• Blocks UV radiation
• Moderates the climate
• Redistributes water in the hydrologic cycle
Types and Sources of Air Pollution
 Air Pollution
Chemicals added to the atmosphere by natural events or human activities in high
enough concentrations to be harmful
 Two categories
• Primary Air Pollutant
• Harmful substance that is emitted directly into the atmosphere
• Secondary Air Pollutant
• Harmful substance formed in the atmosphere when a primary
air pollutant reacts with substances normally found in the
atmosphere or with other air pollutants
Major Air Pollutants
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Major Classes of Air Pollutants
• Particulate Material
• Nitrogen Oxides
• Sulfur Oxides
• Carbon Oxides
• Hydrocarbons
• Ozone
Particulate Material
 Thousands of different solid or liquid particles suspended in air
2014-2015
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• Includes: soil particles, soot, lead, asbestos, sea salt, and sulfuric acid
droplets
 Dangerous for 2 reasons
• May contain materials with toxic or carcinogenic effects
• Extremely small particles can become lodged in lungs
Nitrogen and Sulfur Oxides
 Nitrogen Oxides
• Gases produced by the chemical interactions between atmospheric
nitrogen and oxygen at high temperature
• Problems
• Greenhouse gases
• Cause difficulty breathing
 Sulfur Oxides
• Gases produced by the chemical interactions between sulfur and
oxygen
• Causes acid precipitation
Carbon Oxides and Hydrocarbons
 Carbon Oxides
• Gases carbon monoxide (CO) and carbon dioxide (CO2)
• Greenhouse gases
 Hydrocarbons
• Diverse group of organic compounds that contain only hydrogen and
carbon (ex: CH4- methane)
• Some are related to photochemical smog and greenhouse gases
Ozone
 Tropospheric Ozone
• Man- made pollutant in the lower atmosphere
• Secondary air pollutant
• Component of photochemical smog
 Stratospheric Ozone
• Essential component that screens out UV radiation in the upper
atmosphere
• Man- made pollutants (ex: CFCs) can destroy it
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Sources of Outdoor Air Pollution
 Two main sources
• Transportation
• Industry
 Intentional forest fires is also high
Industrial sources
• Nonferrous smelters. With the exception of iron and aluminum, metal ores
are sulfur compounds. When the ore is reduced to the pure metal, its sulfur
is ultimately oxidized to SO2.
• Oil refining. Sulfur and hydrogen sulfide are constituents of crude oil, and
H2S is released as a gas during catalytic cracking. Since H2S is considerably
more toxic than SO2 before release to the ambient air.
• Pulp and paper manufacture. The sulfite process for wood pulping uses hot
H2SO3 and thus emits SO2 into the air. The kraft pulping process produces
H2S, which is then burned (flared) to produce SO2.
Urban Air Pollution
Photochemical Smog(ex: Los Angeles below):
• Brownish-orange haze formed by chemical reactions involving sunlight,
nitrogen oxide, and hydrocarbons
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Formation of Photochemical Smog
Localized pollution can be complex due to large no. species and transformations
• Early morning traffic increases emissions of both NOx and HC’s (VOCs) as
people drive to work
• Later in the morning, traffic dies down and the NO and VOC’s begin to
react forming NO2, increasing its concentration
• As sunlight becomes more intense NO2 is broken down and its byproducts
form increasing concentrations of O3
• As the sun sets, the production of O3 is halted. O3 that remains in the
atmosphere is then consumed by several different reactions
Formation of photochemical smog
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Environment Protection (I)
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A Note on Units
• Usually expressed as a mixing ratio:
volume analyte/total volume of sample - ppm (v/v)
• May find mg m-3 (esp. for particulates)
• Conversion:
concentration (ppm) = concentration (mg m-3) x 24.0
Molar mass
• Mixing ratio is conserved if temperature pressure changes
Example1
Convert 800 mg m-3 O3 to ppm (v/v)
M O3 = 48 g mol-1
No. moles O3 in 1 m3 air = 800 x 10-3 g/ 48 g mol-1
= 1.67 x 10-2 mol
Volume occupied by 1 mole at 20 °C and 1 atm (STP)
= 24.0 L = 0.0240 m3
Volume O3 in 1 m3 air
= 1.67 x 10-2 mol x 0.0240 m3 mol-1
= 400 x 10-6 m3 = 400 ppm (v/v)
Example2
It is estimated that during the 1952 London smog episode 25,000 metric tons of
coal, with an average sulfur content of 4%, was burned. The mixing depth (the
height of the inversion layer or cap over the city that prevented the escape of
pollutants) was about 150m over an area of about 1200 km2. What was the
approximate SO2 concentration after the coal was burned?
The amount of sulfur in the coal was
(25,000 metric tons)(106 g⁄metric tons)(0.04 g S⁄g coal) = 109 gS
Each mole of sulfur yields 1 mole of SO2 when burned completely. Sulfur has
an atomic weight of 32 g/g-atom, of 16 g/g-atom. Thirty two grams of S thus
produces 64 grams of SO2 so the weight of SO2 produced by the burning coal is
(109 g S)(64 g SO2 ⁄32 g S) = 2 × 109 g SO2
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
And the SO2 concentration is
(2 × 109 g SO2 )(106 μg⁄g)
2
6
(150m)(1200 km )(10
m2 ⁄km2 )
= 11,000 μg⁄m3
However, the measured peak concentration of SO2 during the London episode was
less than 2000 μg⁄m3 .
Expressing the Concentration of Gaseous
Air Pollutants
Gaseous air pollutant concentrations can be expressed in two ways: as micrograms
per cubic meter of air (μg⁄m3 ) and as parts per million (ppm), where
1 volume of gaseous pollutant
1 ppm =
… … … … … … … … … … … . (1)
106 total volumes
or 1 ppm=0.0001% by volume. Conversion between (μg⁄m3 ) is by the ideal gas
law
PV = nRT … … … … … … … … … … … … … … … … … … … … … … … … … (2)
Where:
P = pressure of gas
V = volume of gas
n = number of moles
R = gas constant
T = absolute temperature of gas 𝑖𝑛° 𝐾 𝑜𝑟 ° 𝑅
Example3
The exhaust of an automobile is found to contain 2% by volume CO, at a
temperature of 80° C. Express the CO concentration in the exhaust in (μg⁄m3 ).
2% = 20,000ppm = 20,000L of CO⁄106 L of exhaust
T = 273 + 80 = 353° K
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Environment Protection (I)
2014-2015
P = 1 atmosphere
Gas constant R = 8.315 𝑘𝐽⁄𝑘𝑔 − 𝑚𝑜𝑙𝑒 −° 𝐾 = 0.08315 𝑏𝑎𝑟. 𝑚3 ⁄𝑘𝑔 − 𝑚𝑜𝑙𝑒
−° 𝐾 = 0.08205 𝐿 − 𝑎𝑡𝑚⁄𝑚𝑜𝑙𝑒 − 𝐾 = 1.98 𝑐𝑎𝑙⁄𝑚𝑜𝑙𝑒 −° 𝐾
R = 0.082 L − atm⁄mole −° K
Mol.weight of CO = 12 + 16 = 28 g⁄mole
From the ideal gas law,
PV = nRT =
Weight of CO
RT
Molecular weight of CO
Or, solving for the weight of CO,
weight of CO =
20,000 L of CO
6
10 L of exhaust
(1 atm)(20,000L)(28 g⁄mole)
°
(0.082L − atm −° K )(353 K)
= 1.93 × 104 g
= 1.93 × 104 g⁄106 L = 19.3 g⁄m3
Particulate Pollutants
• Very small solid or liquid particles
• Individual particles may vary in size, geometry, chemical composition and
physical properties
• May be of natural origin (pollen or sea spray) or man made (dust, fume and
soot)
• Provide a reactive surface for gases and vapours in the formation of
secondary pollutants
• Particles also diffuse light reducing visibility
• Come from stack emissions, dusty processes, unsealed roads, construction
work and many other sources
Particulate Air Pollutants
 Dusts
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Environment Protection (I)
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• large solid particles
 Fume
• solid particles (metallic oxides) formed by condensation of vapours
from a chemical reaction process or physical separation process
 Mist
• liquid particles formed by condensation of vapours or chemical
reaction.
SO3 + H2O
H2SO4
 Smoke
• solid particles formed as a result of incomplete combustion of
carbonaceous materials.
 Spray
• a liquid particle formed by the atomisation of a parent liquid.
Hazardous Air Pollutants
• Asbestos. Sources are construction, demolition, remodeling of existing
structures, replacement of pipes and furnaces, asbestos mining, refining and
fabrication, and soil erosion.
• Mercury. Sources are chlor-alkali manufacture and battery manufacture, and
solid waste incineration.
• Hydrogen sulfide. Sources are kraft paper manufacture, oil refining, and
pipeline transportation.
• Benzene. Sources are petrochemical manufacture, industrial solvent use, and
pharmaceutical manufacture.
• Arsenic. Sources are copper smelting and glass manufacture.
• Fluorides. Sources are primary aluminum smelting and phosphate fertilizer
manufacture.
Measurement of Air Quality
 What is air quality?
• complicated by a lack of knowledge as to what is "clean" and what we mean
by quality
• main reason for air pollution control programs is to protect public health define air quality based on its effects on people and the environment
• effects of air pollution are chronic and not immediately obvious
 Measurements of air quality fall into three classes:
• Measurement of emissions: also called source sampling when a particular
emission source is measured, generally by on the spot tests.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
• Meteorological measurements: Measures meteorological factors that show
how pollutants are transferred from source to recipient.
• Measurement of ambient air quality: Measures the quality of all the air in a
particular place. Almost all the evidence of health effects is based on these
measurements
 Air Sampling Techniques
 Most air pollution monitoring equipment performs the act of sampling and
analysis in one action = real time measurement
 older equipment = intermittent sampling (time lag between when the sample
was obtained and when data was available)
 Almost all gaseous pollutants are monitored by real time analysis Particulate pollutants are still mostly monitored by intermittent sampling,
even though real time methods are available
Air quality monitoring instrumentation
 First generation devices: low cost unpowered devices - require long time to
accumulate data e.g. deposit gauge.
 Second generation devices: powered and require small amounts of time to
produce data e.g. high volume sampler
 Third generation devices: produce instant (continuous data) e.g.
nephelometer, gravimetric microbalance, remote UV-visible detectors and
remote infra red sensors
 Particulates – Deposit Gauge
 involves simple collection of dust that settles to the earth by gravitation
 generally over a period of 30 days - 1 data point per month
 suffer from many problems (uncooperative pigeons and drunks who can’t
find anywhere else to go)
 Particulates – Hi Vol Sampler
 most commonly used particle sampling method
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
 analysis is gravimetric - filter is weighed before and after the analysis on an
analytical balance, and difference is particulates collected
 A standard high volume sampler collects particles in the size range from 0.1
- 100m
 airflow is measured by a small flow meter (calibrated in m3 air/minute)
 particulate concentration measured is referred to as the Total Suspended
Particles (TSP), = combination of settleable particles and suspended
particles
 expressed as g/m3 for a 24hour period – normally as part of 6 day cycle
 PM10 and PM2.5 high volume samplers –only collect particles with
aerodynamic sizes of 10m or less, or 2.5m or less
 recognised by PM10 head, which looks like a cross between a flying saucer
and an overgrown wok!
High-volume sampler
Example4
A clean filter is found to weigh 10.00 g. After 24 hours in a hi-vol, the filter plus
the dust weighs 10.10g. The air flow at the start and the end of the test was 60 and
40 ft3/min, respectively. What is the concentration of particulate matter?
Weight of particulates (dust)= (10.10 − 10.00)g × 106 μg⁄g = 0.1 × 106 μg
Average air flow = (60 + 40)⁄2 = 50 ft3 ⁄min
Total air through the filter = 50 ft3 ⁄min × 60 min⁄hr × 24 hr⁄day × 1day
= 72,000ft3 × 0.0283 m3 ⁄ft3 = 2038m3
Total suspended particulate matter= (0.1 × 106 μg)⁄2038m3 = 49 μg⁄m3
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
 Particulates – Nephelometers
 devices which use the scattering of light to measure the size and number of
particles in a given air sample
 best used to determine the amount of particulate matter in different size
fractions
 usually used to examine the amount of particulate material in the 0.1 –
2.5m size range – that which presents the greatest risk to human health
Diagram of a nephelometer
Measurement of Gases
 Gases – Hydrogen Sulfide
 Automatic Intermittent Sampling Gas Chromatographic Method.
 applicable to ambient air with H2S concentrations in the range 0.003 - 2ppm
and is totally specific
 GC is designed to sample air automatically at least ten times per hour
A typical bubbler used for measurement of gaseous air pollutants
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
 Gases – Sulfur Dioxide
 many methods available for determination of SO2
 permits the use of any of the following detection methods;
 UV fluorescence analyser
 flame photometric detector (with or without gas chromatograph)
 electrochemical (coulimetric detector)
 most widely used method in this country is the UV fluorescence
analyser
 UV Fluorescence = air sample drawn into a scrubber chamber (removes
PAH) and then on into an irradiation chamber where it is exposed to UV
light
 SO2 absorbs in 190-230nm
 The amount of fluorescent radiation is directly proportional to the
concentration of SO2
Schematic diagram of the pararosaniline method for measuring SO2
 Gases – Carbon Monoxide
 non-dispersive infrared (NDIR) devices, suitable for detection from 0500ppm by volume
 sample through a flow cell in the instrument where it is irradiated with
infrared radiation
 essentially just a modified dual beam infrared spectrophotometer
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Nondispersive infrared spectrophotometer for CO measurement
Reference Methods
 Grab Samples
 Stack Samples
 Smoke and Opacity
 Grab Samples
 conducted by static, grab, intermittent or continuous procedures
 first air monitoring used static sampling - simple and cheap – requires days
for data e.g. deposit gauge
 Grab sampling not commonly used to monitor ambient air quality – uses
bladders of syringes
 Stack Sampling
 emissions associated with combustion, velocity and temperature may be
much higher than ambient conditions - measure to correct to standard
conditions
 Velocity data determined from pressure measurements utilising a pitot-tube
are necessary to calculate mass loading to the atmosphere, i.e., plant
emission rates
 requires airflow through the sampling probe to be at the same rate as that
flowing in the waste gas stream = isokinetic
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
A stack sampling train
 Smoke and Opacity
The Ringelmann test was at one time conducted by comparing the blackness of
a card, with the blackness of the observed plume. Modern practice consists of
training enforcement agents to recognize Ringelmann opacities by repeated
observation of smoke of predetermined opacity. White smoke is reported as
"percent opacity" rather than by Ringelmann number.
Ringelmann scale for measuring smoke opacity
Plume Behaviour
 Effects of plumes are considered local within 500 metres of the stack, and
regional beyond this.
 Mixing or dispersion of the waste gases and products into the atmosphere =
plume behaviour.
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Environment Protection (I)
Types of Plumes
 Looping plumes
 Coning plumes
 Fanning plumes
 Fumigating
Plume shapes and atmospheric stability
2014-2015
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
CHAPTER 6
Solid Waste
 Wastes : “substances or objects which are disposed of or are intended to be
disposed of or are required to be disposed of by the provisions of the law”
 Disposal : “any operation which may lead to resource recovery, recycling,
reclamation, direct re-use or alternative uses”
 Kinds of Wastes
 Solid wastes: domestic, commercial and industrial wastes especially
common as co-disposal of wastes
Examples:
plastics, styrofoam containers, bottles, cans, papers, scrap
trash
iron, and other
 Liquid Wastes: wastes in liquid form
Examples:
domestic washings, chemicals, oils, wastewater from ponds, manufacturing
industries and other sources
 Classification of Wastes according to their Properties
 Bio-degradable :can be degraded (paper, wood, fruits and others)
 Non-biodegradable : cannot be degraded (plastics, bottles,
machines,cans, styrofoam containers and others)
old
 Classification of Wastes according to their Effects on Human Health and the
Environment
 Hazardous wastes
Substances unsafe to use commercially, industrially, agriculturally, or
economically that are shipped, transported to or brought from the country of
origin for dumping or disposal in, or in transit through, any part of the
territory of the Philippines
 Non-hazardous
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Substances safe to use commercially, industrially, agriculturally, or
economically that are shipped, transported to or brought from the country of
origin for dumping or disposal in, or in transit through, any part of the
territory of the Philippines
 Sources of Wastes
 Residential
 Commercial
 Municipal
 Industrial
 Open areas
 Treatment plants
 Agricultural
 Quantities of Municipal Solid Waste
The quantities of MSW generated in a community may be estimated by:
 Input analysis
 Secondary data analysis
 Output analysis
 Characteristics of Municipal Solid Waste
 Gross composition
 Moisture content
 Particle size
 Chemical composition
 Density
Gross composition: may be the most important characteristic affecting MSW
disposal, or the recovery of materials and energy from refuse. Composition varies
from one community to another, as well as with time in any one community.
Moisture content of solid wastes usually is expressed as the weight of moisture per
unit weight of wet or dry material. The moisture content of MSW may vary
between 15% and 30% and is usually about 20%. Moisture is measured by drying
a sample at 77℃ (170℉) for 24 hours, weighing, and calculating as follows:
Dr. Nabaa Shakir Hadi
M=
Environment Protection (I)
2014-2015
w−d
× 100
w
Where:
M = moisture content, in percent
W = initial, wet weight of sample
d = final, dry weight of sample
The chemical composition of solid wastes is important in evaluating alternative
processing and recovery options. If solid wastes are to be used as fuel, The four
most important properties to be known are:
1. Proximate analysis
a. Moisture (loss at 105℃ for 1h)
b. Volatile matter (additional loss on ignition at 950℃)
c. Ash (residue after burning)
d. Fixed carbon (remainder)
2. Fusing point of ash
3. Ultimate analysis, percent of C(carbon), H(hydrogen), O(oxygen),
N(nitrogen), S(sulfur), and ash
4. Heating value
 Collection
Collection vehicles impact :




Number of working crews required and therefore job opportunities;
Capital and operational costs;
Location of landfill and/or transfer stations; and
Type of on-site storage.
On-site storage
On-site storage options
 Waste volumes;
 Waste types; and
 Collection vehicles.
Transfer System:
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Environment Protection (I)
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A Transfer System consists of a transfer station and a fleet of large capacity
vehicles which provide long haul for refuse - So that the fleet of small capacity
collection vehicles is enabled to focus on the job of collection.
 Assist in the reduction of haulage costs;
 Reduce the congestion of traffic at the landfill; and
 Provide opportunities for recycling.
Transfer Truck:
 Waste is discharged directly from the collection vehicles into the loading
system of the transfer vehicles
 No waste storage, therefore less need for odor and vector control
 Usually used for small stations only
Transfer station method of solid waste collection
What are route collection system?
 Area to be served
 Types and weights/volumes of waste generated
 Presence or lack of material recycling facility (MRF)
 Presence or lack of transfer stations
 Treatment systems-landfill, anaerobic digestion, composting, incineration,
etc.
 Environmental constraints
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Environment Protection (I)
2014-2015
 Economic constraints
 Vehicular fleet, size and quality
 Disposal
 On-site (at home)
 Open Dump
 Sanitary Landfill
 Incineration
 Ocean dumping
 Open Dump
 Unsanitary, draws pests and vermin, harmful runoff and leachates, toxic
gases
 Still accounts for half of solid waste
 Several thousand open dumps in the USA
 Sanitary Landfill
 Layer of compacted trash covered with a layer of earth once a day and a
thicker layer when the site is full
 Require impermeable barriers to stop escape of leachates: can cause
problem by overflow
 Gases produced by decomposing garbage needs venting
Arrangement of cells in an area- method landfill
Site selection criteria for a landfill
 Is it too close to airports? (bird hazard to aircrafts)
 Is it on a flood plain/wetland?
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Environment Protection (I)
2014-2015
 Is it too close to a fault (200 feet or less)?
 Is it within seismic zones?
 Is it located on unstable areas, such as landslide-prone areas, areas with
sinkholes etc.?
Properly designed Sanitary landfills:
 Prevent water infiltration and leaching of toxic fluids
(LEACHATE = a liquid that has passed through or emerged from solid
waste and contains soluble, suspended, or miscible materials removed from
such waste)
 Prevent water pollution
 Reduce Vermin and pests
 Reduce smell, toxic gases and fire hazard
Problems with landfills





Landfills require space
Produce methane gas (can be used for energy, or can cause climate change)
Leachate must be collected and treated
Potential for water pollution
NOT a long-term remedy
 Incineration (burning):
 Significantly reduces the volume of garbage
 Produces heat energy for generating electricity
 Materials such as batteries, glass etc. are NOT suitable for incineration
 Causes air pollution
 Creates toxic ash and other solid waste
 Ocean dumping
 Out of sight, free of emission control norms
 Contributes to ocean pollution
 Can wash back on beaches, and can cause death of marine mammals
 Preferred method: incineration in open sea
 Ocean Dumping Ban Act, 1988: bans dumping of sewage sludge and
industrial waste
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Environment Protection (I)
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 Dredge spoils still dumped in oceans, can cause habitat destruction and
export of fluvial pollutants
 Pollution Prevention: is the use of materials processes or practices that reduce
or eliminate the creation of pollutants or wastes at the source.
What are Waste




Wastewater
Air emissions
Solid waste
Energy
 Preventing Waste
 packaging waste reductions and changes in the manufacturing process
 use biodegradable materials
Source
Reduction
POLLUTION
CONTROL
Reuse
Treatment
POLLUTION
PREVENTION
 Pollution Prevention Methods
 Process elimination
 Housekeeping
 Inventory management
 Waste segregation
 Reuse / recycle
 Raw material substitution
 Equipment modifications
 Process changes
Disposal
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
 Pollution Prevention Program
 Top management commitment
 Champion
 Waste tracking & cost allocation
 Employee involvement and training
 Recurring waste minimization assessments
 Technology transfer and crossfeed
 Solid waste management
may be defined as that discipline associated with the control of generation,
storage, collection, transfer and transport, processing, and disposal of solid wastes
in a manner that is in accord with the best principles of public health, economics,
engineering, conservation, aesthetics, and other environmental considerations, and
that also is responsive to public attitudes
Simplified diagram showing the interrelationships of the functional elements in a
solid waste management system.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
CHAPTER 7
Noise Pollution and Control
What IS Sound?
 Sound is really tiny fluctuations of air pressure
– units of pressure: N/m2 or psi (lbs/square-inch)
 Carried through air at 345 m/s (770 m.p.h) as compressions and rarefactions in air
pressure
Compressed gas
wavelength
rarefied gas
Properties of Waves
 or T
pressure
horizontal axis could be:
space: representing snapshot in
time
time: representing sequence at a
particular point in space
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Environment Protection (I)
2014-2015
 Wavelength () is measured from crest-to-crest
– or trough-to-trough, or upswing to upswing, etc.
 For traveling waves (sound, light, water), there is a speed (c)
 Frequency (f) refers to how many cycles pass by per second
– measured in Hertz, or Hz: cycles per second
– associated with this is period: T = 1/f
 These three are closely related: f = c
Longitudinal vs. Transverse Waves
 Sound is a longitudinal wave, meaning that the motion of particles is along the
direction of propagation
 Transverse waves—water waves, light—have things moving perpendicular to
the direction of propagation
Sound Wave Interference and Beats
 When two sound waves are present, the superposition leads to interference
– by this, we mean constructive and destructive addition
 Two similar frequencies produce beats
– spend a little while in phase, and a little while out of phase
– result is “beating” of sound amplitude
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Environment Protection (I)
in phase: add
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Singal A
Singal B
A+B
out of phase: cancel
(interference)
Characteristics of sound waves:
 The amplitude of the pressure variations,
 The frequency,
 The wavelength in air, and
 The speed of the sound wave.
Sound Intensity
 Sound requires energy (pushing atoms/molecules through a distance), and
therefore a power
 Sound is characterized in decibels (dB), according to:
– sound level = 10log(I/I0) = 20log(P/P0) dB
– I0 = 1012 W/m2 is the threshold power intensity (0 dB)
– P0 = 2105 N/m2 is the threshold pressure (0 dB)
– atmospheric pressure is about 105 N/m2
 Examples:
– 60 dB (conversation) means log(I/I0) = 6, so I = 106 W/m2
• and log(P/P0) = 3, so P = 2102 N/m2 = 0.0000002 atmosphere!!
– 120 dB (pain threshold) means log (I/I0) = 12, so I = 1 W/m2
• and log(P/P0) = 6, so P = 20 N/m2 = 0.0002 atmosphere
– 10 dB (barely detectable) means log(I/I0) = 1, so I = 1011 W/m2
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
• and log(P/P0) = 0.5, so P  6105 N/m2
The sound pressure level (SPL):
SPL(dB) = 20 log10 (
P
)
Pref
Where:
SPL(dB) = sound pressure level, in dB
P = pressure of sound wave, N/m2
Pref = some reference pressure, generally chosen as the threshold of hearing,
0.00002 N/m2
Example1
Find the sound pressure level for a sound with a pressure of 124Mbar.
P
124
SPL(dB) = 20 log10 ( ) = 20 log10 (
) = 116𝑑𝑑
Pref
0.00002
1bar =14.7 Ib/in2 =100Kpa
Mbar =100×10-6×103pa =0.1pa
1Mbar =0.1 pa
Example 2
A jet engine has a sound pressure level of 80 dB, as heard from a distance of 50
feet. Aground crew member is standing 50 feet from a four-engine jet. What SPL
reaches her ear when the first engine is turned on? The second, so that two engines
are running? the third? Then all four?
When the first engine is turned on, the SPL is 80dB, provided there is no other
comparable noise in the vicinity. To determine, from Figure6.3, what the SPL is
when the second engine is turned on, we note that the difference between the two
engine intensity levels is
80 – 80 = 0
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
From the chart, a numerical difference of 0 between the levels being added gives a
difference of 3 between the total and the larger of the two. The total SPL is thus
80 + 3 =83 dB
When the third engine is turned on, the difference between the two levels is
83 – 80 = 3 dB
Yielding a difference from the total of 1.8, for a total IL of
83 + 1.8 = 84.8 dB
When all four engines are turned on, the difference between the sounds is
84.8 – 80 = 4.8 dB
Yielding a difference from the total of 1.2, for a total IL of 86 dB.
Chart for combining different sound pressure levels. For example: combine 80 and
75dB . The difference is 5dB. The 5-dB line intersects the curved line at 1.2dB;
Thus the total value is 81.2dB. (Courtesy of General Radio.)
What is noise pollution?
Any unwanted sound that penetrates the environment is noise pollution.
In general noise pollution refers to any noise irritating to one's ear which comes
from an external source.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Sources of noise pollution
• Street traffic
• Rail roads
• Airplanes
• Constructions
• Consumer products9
Level of tolerance
• Normal level of tolerance is 80dbA.
• Sound level below and above this is considered to be as noise pollution
 Effects of noise pollution
• There are about 25000 hair cells in our ear which create wave in our ear,
responding to different levels of frequencies.
• With increasing levels of sound the cells get destroyed decreasing our ability
to hear the high frequency sound
Be cautious from today
• Irreversible hearing loss.
• Blood pressure rise of 5 to 10 mmHg on 8 hrs of exposure to even 70 db of
sound level.
• Hearing loss begins at 80- 90 dbA. 140 dbA is painful and 180 dbA can even
kill a person.
• Amplified rock music is 120 dbA.
• Most of the electronic vehicles and motors are above 80 dbA level.
• High noise levels may interfere with the natural cycles of animals, including
feeding behavior, breeding rituals and migration paths.
Symptoms of occupational hearing loss
• Feeling of fullness in the ear.
• Sounds may seem muffled.
• Cannot hear high frequency sounds.
• Ringing in the ears while listening to the high frequency sounds.
• Loud noise for a long period of time, or sudden burst of sound can cause
occupational hearing loss.
• Hearing that does not return after an acute noise injury is called a permanent
threshold shift.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Actions taken and to be taken
• There are a variety of effective strategies for mitigating adverse sound levels
• use of noise barriers.
• limitation of vehicle speeds
• alteration of roadway surface texture.
• limitation of heavy duty vehicles
• use of traffic controls that smooth vehicle flow to reduce braking and
acceleration, innovative tire design and other
Legistation
• Noise Regulation Rules under the Environment (Protection) Act of 1986.
• Features
• Industrial- 75db
• Commercial- 65 db
• Residential zones- 55 db
• Zones of silence
• No public address system after 10:00 pm and before 06:00 am.
 Sound Level Meter
Definition: The instrumentation to determine sound level or noise level is referred
as a sound level meter.
Principle: The pressure of the sound waves under study actuates the microphone
thus converting the acoustical energy into electrical current which in turn serve to
operate the display device.
Design:
The various elements in a sound level meter are
• The transducer; that is, the microphone
• The electronic amplifier and calibrated attenuator for gain control
• The frequency weighting or analyzing possibilities
• The data storage facilities
• The display
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Schematic representation of a sound level meter
The best means of quantitatively measuring human response to noise:
 Traffic Noise Index (TNI)
 Sones
 Perceived Noise Level (PNdB)
 Noise and Number Index (NNI)
 Effective Perceived Noise Level (EPNdB)
 Speech Interference Level (SIL)
 Control of Noise Pollution
The techniques employed for noise control can be broadly classified as
(1) Control at source
(2) Control in the transmission path
(3) Using protective equipment.
(1)Noise Control at Source
The noise pollution can be controlled at the source of generation itself by
employing following techniques.
(a) Reducing the noise levels from domestic sectors
(b) Maintenance of automobiles
(c) Control over vibrations
(d) Low voice speaking
(e) Prohibition on usage of loud speakers
(f) Selection of machinery
(g) Maintenance of machines
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
(2) Control in the transmission path
The change in the transmission path will increase the length of travel for the
wave and get absorbed/refracted/radiated in the surrounding environment.
The available techniques are:
(a) Installation of barriers
(b) Installation of panels or enclosures
(c) Green belt development
(3)Using protection equipment
• Protective equipment usage is the ultimate step in noise control technology, i.e.
after noise reduction at source and/or after the diversion or engineered control of
transmission path of noise.
• The usage of protective equipment and the worker’s exposure to the high noise
levels can be minimized by following.
(a) Job rotation
(b) Exposure reduction
(c) Hearing protection
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
CHAPTER 7
Radioactive Pollution
Radioactive Exhibiting radioactivity: For legal and regulatory purposes, the
meaning of radioactive is often restricted to those materials designated in national
law or by a regulatory body as being subject to regulatory control because of their
radioactivity.
Natural Radionuclides
Radionuclides
Unstable nuclides
Radioactivity
Emission of radiation
Radiation types
Alpha, beta, gamma, neutron,
and X ray
Activity
Decay rate of radionuclide
Half-life
Time to half activity
Radioactivity: the phenomenon whereby atoms undergo spontaneous random
disintegration, usually accompanied by the emission of radiation.
Activity: the rate at which nuclear transformations occur in a radioactive material.
Used as a measure of the amount of a radionuclide present. Unit Becquerel, symbol
Bq. 1Bq=1 transformation per second
Half Lives: For a radionuclide, the time required for the activity to decrease, by a
radioactive decay process, by half. Symbol t1/2.
Types of radiation
Alpha radiation (𝛼): is a positively charged helium nucleus emitted by a larger
unstable nucleus. It is a relatively massive particle, but it only has a short range in
air (1-2 cm) and can be absorbed completely by paper or skin. Alpha radiation can,
however, be hazardous if it enters the body by inhalation or ingestion, because
large exposures can result in nearby tissues, such as the lining of the lung or
stomach.
Beta radiation (𝛽): is an electron emitted by an unstable nucleus. Beta particles
are much smaller than alpha particles and can penetrate further into materials or
tissue. Beta radiation can be absorbed completely by sheets of plastic, glass, or
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
metal. It does not normally penetrate beyond the top layer of skin. However large
exposures to high-energy beta emitters can cause skin burns. Such emitters can
also be hazardous if inhaled or ingested.
Gamma radiation(𝛾): is a very high energy photon (a form of electromagnetic
radiation like light) emitted from an unstable nucleus that is often emitting a beta
particle at the same time. Gamma radiation causes ionization in atoms when it
passes through matter, primarily due to interactions with electrons. It can be very
penetrating and only a substantial thickness of dense materials such steel or lead
can provide good shielding. Gamma radiation can therefore deliver significant
doses to internal organs without inhalation or ingestion.
Gosmic radiation: comes from deep space. It is a mixture of many different types
of radiation, including protons, alpha particles, electrons and other various exotic
(high energy) particles. All these energetic particles interact strongly with the
atmosphere and, as a result, cosmic radiation at ground level becomes primarily
muons, neutrons, electrons, positrons and photons. Most of the dose at ground
level comes from muons and electrons.
X rays: are high-energy photons, like gamma radiation, and are produced
artificially by the rapid slowing down of an electron beam. X rays are similarly
penetrating and, in the absence of shielding by dense materials, can deliver
significant doses to internal organs.
Neutron radiation (𝑛): is a neutron emitted by an unstable nucleus, in particular
during atomic fission and nuclear fusion. Apart from a component in cosmic rays,
neutrons are usually produced artificially. Because they are electrically neutral
particles, neutrons can be very penetrating and when they interact with matter or
tissue, they cause the emission of beta and gamma radiation. Neutron radiation
therefore requires heavy shielding to reduce exposures.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Figure6.3 Common types of radiation emitted from radioactive sources and ability
of each type to break through the barriers (UNSCEAR., 2000)
Radiations and Radioactivity decay
These radiations are of two types :
(1) Non-ionizing radiations
(2) Ionizing radiations
Non-ionizing radiations: Radiation that is not ionizing radiation. Examples are
ultraviolet radiation, visible light, infrared radiation and radiofrequency radiation.
Ionizing radiations: for the purposes of radiation protection, radiation capable of
producing ion pairs in biological materials(s). examples are alpha particles, gamma
rays, X rays and neutrons.
Radioactive Pollution and their Sources
There are two sources of radiation pollution
1. Natural Sources of Radiation
(i) Atomic radioactive
(ii) Cosmic rays
(iii) Naturally occurring radioisotopes
(iv) Radioactive elements
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
2. Anthropogenic Sources of Radiation
(i) Diagnostic medical applications
(ii) Nuclear Tests
(iii) Nuclear Reactors
(iv) Nuclear explosions
(v) Nuclear Wastes
(vi) Nuclear material processing.
Biological Effects of Ionizing Radiation on the Human Body
The two types of effects are :
(i) genetic and
(ii) nongenetic or body damage.
In genetic damage, genes and chromosomes get altered. Its effect may become
visible as deformations in the offsprings (children or grandchildren). Alterations or
breaks in the genetic material, that is DNA (deoxyribonucleic acid)- the molecule
containing genetic information, is called mutation. In nongenetic effects, the harm
is visible immediately in the form of birth defects, burns, some type of leukemia,
miscarriages, tumors, cancer of one or more organs and fertility problems.
Radiation Doses and Radiation Effects
The biological damage caused by the radiation depends upon the following factors
:
(i) the time of exposure
(ii) the intensity of radiation
(iii) the type of ionizing radiation (i.e. its penetration power)
(iv) whether the radiation is emanating from outside or inside the human body.
Dr. Nabaa Shakir Hadi
Environment Protection (I)
2014-2015
Units
Dose : General term for a measure of the energy deposited by radiation in a target.
Absorbed dose: The energy imparted by ionizing radiation to a suitably small
volume of matter divided by the mass of that volume. Unit gray, symbol Gy.
1Gy=1 joule per kilogram.
Equivalent dose: A measure of the dose to a tissue or organ designed to reflect the
amount of harm caused to the tissue or organ. Obtained by multiplying the
absorbed dose by a radiation weighting factor to allow for the different
effectiveness of the various types of radiation in causing harm to tissue. Unit
sievert, symbol Sv.
Table 6.2 Effects of radioactive radiation on living beings
Type
of
Effect on the body
radiation
α − particles Generally they cannot penetrate the skin. But if their
sources is inside the body, they can cause damage to
bones or lungs.
β − particles Can penetrate the skin but cannot damage the
tissues. They can cause damage to skin and eyes
(cataract).
γ − radiation Can easily penetrate the body and pass through
it.They cause damage to cell structure.
Can travel very far and pass through the body tissues
X − rays
except bones. They can cause damage to the cells.