Water and
its Treatment
Applied Chemistry
I. Water Treatment
A. Sources of Water on Earth
1. Physical States:
a. Solid:
glaciers & ice caps
b. Liquid: oceans, rivers, lakes,
water beneath the ground,
clouds, & rain
c. Gas:
water vapor in the atmosphere
I. Water Treatment
2. Physical Location:
a. Surface water: water located on the
surface of the Earth
b. Ground water: water located beneath
the Earth’s surface
How does a well reach
groundwater?
Types of Precipitation
Snow
Types of Precipitation
Sleet
Types of Precipitation
Rain
Types of Precipitation
Hail
3. Replacement
a. The WATER CYCLE, aka the
HYDROLOGIC cycle, is a continuous
circulation of water between surface water,
the atmosphere, & Earth’s surface.
Any type of moisture that falls
i. Precipitation to the Earth, such as, rain or snow
ii. Evaporation
Change of state from a
liquid to a gas
iii. Transpiration Evaporation of water from
plants
iv. Condensation Change of state from
gas to a liquid (seen as clouds)
precipitation
condensation
transpiration
evaporation
runoff
groundwater
surface
water
B. Types of Water
1. Drinking water, aka potable
water or pure or tap water, is
water that is SAFE to drink.
2. Wastewater is used water
produced by communities
Sources: homes, businesses, schools
C. Water Treatments
1. Water Treatment Plant
2. Wastewater Treatment Plant
1. WATER TREATMENT PLANT
a. Operates to produce DRINKING
water.
b. Our local water treatment plant is
Forest Park.
c. Overview:
From surface and/or ground water  to
water treatment plant  to homes,
businesses, schools through pipes.
d. Basic process: physical process of
filtration
Lake Galena in Peace Valley
Park
Water Filtration Plant
Water Filtration Plant
1. Screening: physical process used
to remove large objects from water.
2. Flash Mixer: chemical
pretreatment
3. Coagulation: reaction of alum
with dirt to form sticky globs
4. Flocculation: process of attracting
more dirt to sticky globs to form
floc.
5. Sedimentation: process of floc
settling to bottom
a. Sludge: settled solid matter that is
removed from the bottom of tank
(aka residual solids)
6. Filtration: physical process of
passing clean liquid above sludge
through layers of sand and gravel
7. Chlorination: addition of chlorine to
kill bacteria before distribution to
community
8. Clear Wells: storage of filtered,
chlorinated water at the plant
2. WASTEWATER TREATMENT PLANT
a. Operates to clean USED water.
b. Overview: from sewer lines  to
plant  to surface water.
c. Basic processes: physical, chemical
and biological
i.
Influent (in): wastewater entering plant
from the community
ii. Effluent (exit): water that leaves the
plant to a receiving system.
iii. Trickling Filters: old cleaning system (slow) –
removes organic material
WASTEWATER TREATMENT PLANT
Influent (in)
Effluent (exit)
Trickling Filters
II. Wastewater Treatment–
began in Water Pollution Control Act
was passed in 1948. Standards
controlled by EPA.
A. Primary Treatment: separates large
solid waste from liquid in wastewater
1. The entire process of screening,
skimming/filtering, and settling
2. Includes physical processes only
3. Examples:
stirring
settling
diluting
sedimentation
filtering
dissolving
change in state, size, shape
B. Secondary Treatment
1. Treating wastewater through chemical
and biological methods
2. Relies on biological processes to remove
organic waste.
3. Wastewater is sent to aeration tanks or
trickling filters where it is treated with
microorganisms that feed on the organic
waste. Next the wastewater is chlorinated
to kill disease-causing organisms. Before
released to a stream or river, the
wastewater is dechlorinated.
4. Tests for Monitoring
Activated Sludge
a. Qualitative tests involve the sensory
observations.
Examples: color, clarity, odor
b. Quantitative tests use instruments
to make measurements.
Examples: temperature, pH, oxygen levels,
chlorine levels
Quantitative Tests
• SLAM: Standard Laboratory Analysis
Method – to test and monitor waste
water
• SOP: Standard Operating Procedures
– provides a method of producing
reliable results through
standardization of sampling and
testing; describes plant operations.
III. Water Pollution
A. Ground Water
1. Formation: Water travels down through
the earth’s surface
2. This is called seepage.
3. Water seeps or trickles down through the
earth at a rate of several inches to few feet
per day.
4. Ground water is the largest single supply
of fresh water. It is 30 times greater than
lakes and 3000 times greater than
streams.
Water Pollution
2. Watershed: total drainage area over
which water flows to a common point.
a. The watershed in our area is the Schuykill
Watershed.
3. Runoff: water that flows over a
watershed after a rainfall or snow melt
4. Aquifer: porous rock structure that holds
water beneath the earth’s surface
•
Ex. of an aquifer: sand or sandstone
Water Pollution
5. Water Table: top of the aquifer
6. Aquitard: earth materials that
prevent the easy flow of water
Ex. of an aquitard: Clay or basalt
precipitation
condensation
transpiration
evaporation
runoff
watershed
Groundwater
water table
aquifer
seepage
surface
water
B. Factors Affecting the
Movement of
Water
1. Sediment: earth materials, such as
rock fragments, stones, sand, and
clay, that are deposited by water,
wind, or ice
2. “Matter that settles” refers to
sediment
Factors Affecting the Movement of Water
3. Composition of the earth
materials
a. Permeability – the ability of a
substance (earth’s materials) to
allow water to pass through it
b. Pores – holes or spaces between
earth’s materials
c. The amount of water penetrating
depends upon the spacing.
Pore Size
LARGE
GRAVEL
MEDIUM
SAND
SMALL
CLAY
C. Contamination of
Ground Water
1. Contamination: any type of impurity
a. Pesticide: any chemical used to kill
pests (insects or small animals)
b. The safe concentration level for each
chemical is different for each chemical.
c. A major cause of water pollution in
Pennsylvania is mining.
Contamination of
Ground Water
2. Plume – the distribution of
contaminated ground water; the
spread of pollution
a. Area source: pollution over a wide area
i. The plume has a wide range of
concentration of pollutant.
ii. There are no regions of very high or low
levels of pollutant.
iii.Example: agricultural application
Contamination of Ground Water
• Shade in the area predicting the
distribution of contamination from
pesticide application on farm land.
Farm
Land
Contamination of Ground Water
b. Point Source: pollution over a single
or small point
i.
The plume has a wide range
concentration of pollutant.
ii. High levels of pollutant are close to the
source.
iii. Low levels of pollutant are far from the
source.
iv. Example: leaks from storage tanks
Contamination of Ground Water
• Shade in the area predicting the
distribution of contamination from a
broken pipe at the gas station.
Gas station
Fruitvale Activity
• Hypothesis: educated or best guess
• Universal indicator: a mixture of
compounds used to provide
information on pH over a wide range
of values
• ppb = parts per billion
Draw a plume to show unsafe areas where
pesticide levels in the water exceed 1 ppb. Mark
the source with an X.
Concentration
Range
Code
Not detected;
less than .1 ppb
1
.11 ppb - .9 ppb
2
.81 ppb – 4 ppb
3
4.1 ppb – 32
ppb
4
More than 32
ppb
5
1
1
1
1
2
1
3
4
3
4
3
1
4
5
2
1
3
2
1