Title: Chapter 19 Notes
1Chapter 19 Notes
2Types and Sources of Water Pollution
- Water Pollution any chemical, biological or
physical change in water quality that has a
harmful effect on living organisms or makes water
unsuitable for desired use
3Major Types of Water Pollution
- Disease causing agents (pathogens) bacteria,
viruses, protozoa, and parasitic worms that come
from sewage and untreated human and animal waste - Indicator of water quality colonies coliform
bacteria - 0-100drinking water, max of 200 for swimming
water
4Oxygen Demanding Waste
- Organic wastes that can be decomposed by aerobic
bacteria. Bacteria deplete water of oxygen, which
causes death to fish and other aerobic aquatic
life - BOD biological oxygen demand amount of oxygen
needed by aerobic decomposers to break down
organic matter in a certain volume of water over
a five day period at twenty degrees Celsius
5Water Soluble Inorganic Chemicals
- Acids, salts, and compounds of toxic metals (Hg,
Pb) - High levels of these make water unfit to drink,
harm fish, and other aquatic life, lower crop
yields and accelerates metal corrosion
6Inorganic Plant Nutrients
- Water soluble nitrates and phosphates that cause
excessive growth of algae and other aquatic
plants, which die, decay and deplete water of
oxygen, killing fish. - Excessive levels of nitrates lower the oxygen
carrying capacity of blood causing Blue Baby
Syndrome
7Organic Chemcials
- Oil, plastic, gas, pesticides, solvents, and
detergents - Threaten human fish and aquatic life
- Just downright poisonous
8Sediment or suspended matter
- Clouds the water and reduces photosynthesis,
which disrupts food webs and carries bacteria and
pesticides - It clogs and fills lakes, streams and harbors
- Decreases the efficiency of chlorine to disinfect
water
9Water Soluble Radioactive Isoptopes
- Can be biologically magnified in tissues and
organs - Ionizing radiation can cause birth defects,
cancer and genetic damage
10Thermal Pollution
- Heat absorbed by water to cool industrial and
power plants which lowers the water quality by
lowering dissolved oxugen leels making aquatic
organisms more vulnerable to disease, parasites
and toxic chemcials - Causes fish kills
- Increases the growth rate of algae
Finland
11Genetic Pollution
- When aquatic ecosystems are disruoted by
deliberate or accidental introduction of
non-native species, which reduces biodiversity
and causes economic loss. - These species are usually introduced in the
ballast water of ships
12Point source Pollution
- 1. Point sources discharge pollutants at
specific locations (pipes, ditches, sewers at
factories, sewage treatment plants, active and
abandoned underground mines, offshore oil wells,
oil tankers). These are controlled in developed
countries and uncontrolled in developing
countries.
13Non-point Source
- 2. Non Point Sources pollutants that cannot be
traced to a specific site. These include
large land areas that pollute due to runoff,
subsurface flow, deposition from the
atmosphere. Agriculture produces non-point
pollution in the form of sediment, inorganic
fertilizers, manure, salts dissolved in
irrigation water and pesticides.
14 II. Pollution Of Streams and Lakes
- A. Stream and River Pollution
- 1. Streams and rivers usually recover rapidly as
long as streams are - not overloaded with pollutants and flow is not
reduced due to drought, damming, or diversion for
agriculture and industry
15 II. Pollution Of Streams and Lakes
- Oxygen Sag Curve when bacteria reduces or
eliminates populations of organisms with high
oxygen requirements. This depends upon stream
volume, flow rate, temperature, pH level and
volume of degradable wastes. This curve can also
be done for thermal pollution
16Fig. 19.3, p. 479
17Reduction of Stream Pollution
- require cities to withdraw drinking water
downstream rather than upstream, which improves
water quality - Water pollution laws of 1970 have increased the
number and quality of wastewater treatment plants
which in the US and other developed countries has
reduced or eliminated point source pollution
18Lake Pollution
- Dilution is less effective
- Lakes and reservoirs contain stratified layers
that undergo little vertical mixing.
Stratification reduces levels of dissolved oxygen
(especially on the bottom) - Ponds contain small volumes of water
- Lakes are more vulnerable to contamination by
plant nutrients, oil, pesticides, and toxic
substances (Pb,Hg,Se) and acid deposition
19Fig. 19.4, p. 481
20Eutrophication
- Natural nutrient enrichment
- Cultural Eutrophicationwhen human activities
near urban or cultural areas greatly accelerate
the input of nutrients to a lake. Mostly nitrates
and phosphates cause this.
21Eutrophication
- During hot weather, dense growths of algae,
cyanobacteria, duckweed and hyacinths occur and
dissolved oxygen is depleted which kills fish and
other aquatic animals - Excessive nutrients can cause anaerobic bactria
to take over and produce gaseous decomposition
products (CH4, H2S)
22Discharge of untreated municipal sewage (nitrates
and phosphates)
Nitrogen compounds produced by cars and factories
Natural runoff (nitrates and phosphates
Discharge of detergents ( phosphates)
Manure runoff From feedlots (nitrates
and Phosphates, ammonia)
Discharge of treated municipal sewage (primary
and secondary treatment nitrates and phosphates)
Runoff from streets, lawns, and construction lots
(nitrates and phosphates)
Lake ecosystem nutrient overload and breakdown
of chemical cycling
Runoff and erosion (from from cultivation, mining,
construction, and poor land use)
Dissolving of nitrogen oxides (from internal
combustion engines and furnaces)
Fig. 19.5, p. 482
23Fig. 19.6, p. 483
24CANADA
Nipigon Bay
Jackfish Bay
Thunder Bay
Silver Bay
St. Marys R.
St. Lawrence R.
Spanish R.
St. Louis R.
MICHIGAN
Penetary Bay
WISCONSIN
Sturgeon Bay
MICHIGAN
Saginaw Bay
NEW YORK
Niagara Falls
Saginaw R. System
Grand R.
MINNESOTA
Niagara R.
St. Clair R.
Thames R.
Buffalo R.
Detroit R. Rouge R. Raisin R.
Ashtabula R.
PENNSYLVANIA
IOWA
Cuyahoga R.
Maumee R.
Rocky R.
Black R.
ILLINOIS
INDIANA
OHIO
Great Lakes drainage basin
Most polluted areas, according to the Great Lakes
Water Quality Board
Hot spots of toxic concentrations in water and
sediments
Eutrophic areas
Fig. 19.7, p. 484
25Industrial pollution
Suffocated fish
Beaches closed
Sewage runoff
Dead algae
Low dissolved oxygen
Decreased fish population
Mercury- tainted fish
Fig. 19.8a, p. 485
26Suburban sprawl
Lower water levels
Clear water
High dissolved oxygen
PCBs in sediment
Thriving fish population
Fig. 19.8b, p. 485
27Ways To Prevent Cultural Eutrophication
- Use advanced sewage treatment
- Ban or limit phosphates in household detergents
and other cleaners - Practice soil conservation and land use control
to reduce nutrient runoff
28Ocean Hypoxia
- The Dead Zone is an area of the ocean that is
severely oxygen depleted due to cultural
eutrophication - Caused by plant nutrients that get washed down
rivers into the ocean causing algal blooms and
fish kills - Examples Chesapeake bay and the Gulf of Mexico
29Ocean Pollution
- How coastal areas are effected
- 1. wetlands, estuaries, coral reefs, mangrove
swamps bear the majority of the enormous wastes
we ad to the ocean - 2. Most sewage in developing countries is
dumped directly into the ocean without treatment - sewage and agricultural wastes introduce
large quantities of nitrogen and phosphorus to
the water which causes algal blooms
30Ocean Pollution
- Pollutants that are dumped into the ocean
- 1. dredge spoils or materials full of toxic
chemicals scraped from the bottom of harbors and
rivers to maintain channels are dumped from
barges and ships at 110 sites in the Pacific,
Atlantic and Gulf Coasts - 2. sewage sludge-gooey, mud like mixture of
toxic chemicals, infectious agents and settled
solids removed from wastewater at sewage
treatment plants (banned in the US since 1992)
31Ocean Pollution
- Sewage and garbage from merchant marine fleets
- Highly toxic pollutants and high level
radioactive wastes
32Ocean Pollution
- Effects of oil on ocean ecosystems
- Crude petroleum (oil from ground) and refined
petroleum (fuel oil, gasoline, other petroleum
products) pollution comes from normal operation
of offshore wells, washing tankers, releasing
oily water and from pipeline and storage tank
leaks onto the land or into sewers by cities,
individuals and industry (1000Xs that spilled by
the Exxon Valdez).
33Ocean Pollution
- Tar like globs that float on the surface coat
feathers of diving and other birds and the fur of
marine mammals, which destroys their insulation
and buoyancy, which causes death due to the loss
of body heat. - Oil that sinks to the bottom smothers bottom
dwelling organisms (crabs, oysters, mussels,
clams) and can kill coral reefs. - Overall- it is a low risk ecological problem.
34Prevention of Ocean Pollution
- Reduce oil waste and shift to renewable energy
resourcesReduce flow of pollution from the land
streams into the oceans. - Prevent and control air pollution (33 of
pollutants come from emissions). - Prevention
- Discourage sludge dumping and hazardous dredged
material. - Reduce or curtail development of oil drilling and
oil shipping in coastal areas. - Develop land use planning in coastal areas.
- Require double hulls in oil tankers by 2002.
- Recycle used oil
- Reduce genetic pollution in ballast water.
35Prevention and Reduction of Surface Water
Pollution
- Nonpoint pollution
- 1.Leading causeagriculture. Farmers can reduce
fertilizer runoff onto surface waters and
into aquifers by. - Reducing or eliminating the amount of fertilizer
use. - Use slow release fertilizers.
- Alternate crops between row crops and nitrogen
fixation crops - Plant buffer zones between cultivated fields and
nearby surface waters. - Apply pesticides only when needed.
- Use biological controls for pests.
36Prevention and Reduction of Surface Water
Pollution
- Eliminate or reduce inorganic fertilizers and
pesticides for golf courses, lawns and public
lands. - Livestock growers could manage animal density
(reducing manure). Planting buffers, and
locating feed lots. - Create detention basins for animal runoff and
reapply fertilizers to croplands or forestlands. - Reforest critical watersheds (reduces soil
erosion and the severity of flooding and slows
global warming and the loss of wildlife habitants.
37Point Pollution and the Legal Approach
- 2 of the sewage is treated in Latin American,
15 in China, and 30 in India The Clean Water
Act of 1977 and the Water Quality Act of 1987
form the basis of the U.S. effort to control
pollution of the countrys surface waters. - The main goalsafe waters for fishing and
swimming by 1983 and restore and maintain
chemical, physical, and the biological integrity
of the nations waters. - Discharge Trading Policy of 1995 uses market
forces to reduce water pollution. Credits can be
sold for excess reductions- like air pollution
control and SO.
38Sewage Treatment Plants
- Primary sewage treatment a mechanical process to
screen out debris (sticks, stones, rages, etc.),
and suspended solids which settle out as sludge
in a settling tank.
39Sewage Treatment Plants
- Secondary sewage treatment biological process in
which aerobic bacteria are used to remove up to
90 of biodegradable, oxygen demanding organic
wastes. - Trickling filters aerobic bacteria degrade
sewage as it seeps through a bed of crushed
stones covered which bacteria and protozoa. - Activated sludge processsewage is pumped into a
large tank, mixed for hours with bacteria and air
to facilitate degradation by microorganisms.
Then suspended solids settle out as sludge. - Sludge from both primary and secondary treatment
is broken down in an anaerobic digester and then
incinerated, dumped into the ocean, or used as
fertilizer.
40Sewage Treatment Plants
- Advanced Sewage Treatment series of chemical and
physical processes that remove pollutants left in
the water after primary and secondary treatment. - Advanced sewage treatment removes nitrates and
phosphates which contribute to eutrophication of
lakes, slow moving streams, and coastal waters. - These advanced plants cost twice as much to build
and four times as much to operate. Water from
primary, secondary, and advanced treatment plants
is bleached and disinfected by chlorinating. - Sewage Sludge (36 by weight) is applied to
farmland as fertilizer for crops used for animal
feed and human food. - 38 is dumped into landfills16 is incinerated
9 is composted
41Waste lagoon, pond, or basin
Hazardous waste injection well
Mining site
Water pumping well
Buried gasoline and solvent tanks
Pumping well
Road salt
Sewer
Landfill
Cesspoll, septic tank
Leakage from faulty casing
Unconfined freshwater aquifer
Groundwater
Confined freshwater aquifer
Groundwater flow
Discharge
Confined aquifer
Fig. 19.9, p. 487
42Groundwater
- IV. Groundwater prime source of drinking water
and irrigation water. Groundwater cannot cleanse
itself like surface water does. - Reasons for pollution
- groundwater flow is slow, not turbulent
- contaminants are not effectively diluted and
dispersed - groundwater has smaller proportions of
decomposing bacteria - cold temperatures slow decomposition
43Groundwater
- Reasons for Pollution
- underground storage tanks
- landfills
- abandoned waste dumps
- deep well disposal of liquid hazardous waste
- industrial and livestock waste storage lagoons
located near aquifers - industrial waste ponds without liners to prevent
toxic liquid wastes from seeping into aquifers
44VI. Drinking Water Quality
- Protection of drinking water
- UgtSgt Safe Drinking Water Act of 1974 tests fro 64
contaminants - Strengthening Safe water Act
- improving water treatment by combining smaller
water systems for larger ones - strengthening and enforcing public notification
requirements about violations - banning all lead in new plumbing pipes, faucets
and fixtures
45Bottled Water
- International Bottled Water Association tests for
181 contaminants - National Sanitation Foundation certification by
this agency requires tests for 200 chemical and
biological contaminants - EPA does not test or approve water-filtering
devices - One/fourth of it is tap water
- 40 is contaminated by bacteria and fungi
- 1.5 million tons of plastic thrown away
- Oil used to make plastic would power 100,000 cars
for a year. -