Water Pollution

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Transcript Water Pollution

Water Pollution
Chapter 14
Sources of Pollution
• Water Pollution
a. contamination of water with substances
produced through human activities and have
a negative effect on organisms
• Point Source vs. Nonpoint Source
a. point source
1. distinct locations
ex) waste pumped into stream
b. nonpoint source
1. more diffuse areas
ex) runoff
• Common types of pollutants in water
a. human and animal waste
b. inorganic substances
c. organic compounds
d. synthetic organic compounds
e. nonchemical pollutants
Human Wastewater
• Wastewater
a. water produced by human activities
b. biggest challenge?
1. how to keep wastewater from polluting
drinking water
c. 3 concerns
1. decomposition
2. nutrient release
3. disease-causing organisms
• Decomposition of wastewater
a. oxygen-demanding waste
1. organic matter that enters a body of
water and feeds the growth of the
2. biochemical oxygen demand (BOD)
3. dead zones
- area of little life due to lack of oxygen
• Release of nutrients
a. nitrogen and phosphorus
- soaps and detergents in addition to
b. eutrophication
• Disease-causing organisms
a. pathogens – bacteria, viruses and parasites
that can cause an illness
ex) cholera, hepatitis
 top two worldwide
b. more common in developing countries
c. prevention
1. provide safe drinking water
2. proper sanitation
3. proper hygiene
d. indicator species
1. used to detect if pathogen is in drinking water
- most common is fecal coliform bacteria
* e. coli
Treating Wastewater
• Overall approach to various methods
 breakdown of organic matter by bacteria into
CO2, nitrate, and phosphate
• 2 most common
a. septic systems
b. sewage treatment plants
• Treatment of livestock waste – manure lagoons
• Septic Systems
a. rural areas, low population density, lots of land
b. 2 parts  septic tank and leach field
c. septic tank
1. receives wastewater from house
2. three layers
- scum
- septage
- sludge
d. advantage
- no electricity needed
• Sewage Treatment Plants
a. larger population densities, less open land
b. developed countries
- centralized plant
- receives wastewater through network of
underground pipes
Sugar Creek Wastewater Treatment Plant Charlotte, NC
c. Process of sewage treatment plant
1. primary treatment
- Goal “solid waste material to settle out
of wastewater” (sludge)
2. secondary treatment
- Goal “produce CO2, nitrogen, and
phosphorus by using bacteria to
breakdown the majority of the
organic matter in the water
3. tertiary treatment
- Goal “release a wastewater that is as
close to the quality of the body
of water it is going back to”
• Manure Lagoons
a. large, human-made ponds lined with
rubber to prevent leakage of manure into
the groundwater
b. drawback
- leak could happen in the liner
* contaminate groundwater
- applying manure as fertilizer
* runoff into nearby water
Heavy Metals and Other Substances –
Human Health and Environment
• Nitrogen and phosphorus
a. overfertilizing the H2O
• Inorganic compounds
a. lead, arsenic, mercury
• Acids
• Synthetic compounds
a. pesticides, pharmaceuticals, and hormones
• Lead
a. contamination
1. H2O passing through pipes of older
homes, brass fittings, solder
b. who it affects
1. fetuses and infants
2. damage to brain, nervous system, and
c. solution
1. require lead-free pipe installation
• Arsenic
a. occurs naturally in Earth’s crust and
dissolves in groundwater (contamination)
b. contributions to increased amounts
1. mining
2. wood preservatives
c. Symptoms
1. cancers of skin, lungs, kidneys, and
d. solution
1. fine membrane filtration
2. distillation
3. reverse osmosis
• Mercury
a. naturally occurring in water
b. source
1. burning of coal (coal-burning power plants)
2. incineration of garbage, hazardous waste, and
dental supplies
3. petroleum (Hg and Lead)
c. symptoms
1. damage of CNS
d. solution
1. cement plants reduce emissions by 81%
• Acid Deposition
a. source
1. coal-burning power plants
b. formation
1. release of SO2 and NO2 into atmosphere
and converted into sulfuric acid
2. falls as wet or dry acid deposition
c. solution
1. coal scrubbers
d. Acid mine drainage
1. due to flooded
abandoned underground
2. pyrite (type of rock)
breaks down water
into hydrogen and iron
ions producing
acidic water
• Synthetic Organic Compounds
a. “human-made”
b. pesticides
1. 3 concerns
a. pesticides kill a wide variety of related
organisms instead of just targeted species
b. can alter other physiologic functions
ex) DDT
c. inert ingredients
ex) Roundup
c. pharmaceuticals and hormones
1. ~50% of streams contain antibiotics and
reproductive hormones
2. 80% contain nonprescription drugs
3. 90% contain steroids
4. low concentrations and do not yet pose
environmental or human risk
d. industrial compounds
1. “use in manufacturing”
2. dumped directly into water (disposal)
3. Cuyahoga River of Ohio
4. PCBs
- used in producing plastics
- long-term persistence
- lethal carcinogen if ingested
5. PBDEs
- flame retardent
Oil Pollution and Water
• Oil
a. persistent
b. spreads below or on surface of water
c. leaves thick, viscous covering on shorelines
d. sources of oil in water
1. leak in oil platform
2. spills from oil tankers
3. naturally occurring (60%)
e. solution
1. containment booms – open ocean
2. absorbent materials – shorelines
3. chemicals
4. genetically engineered bacteria
Solid Waste and Water
• Discarded materials from houses and
• “garbage”
• Not a toxic hazard
• Dangerous to marine organisms
Sediment Pollution and Water
• Sediment
- sand, silt, and clay carried by moving water
and eventually settles when water slows
• Result of human activities
a. construction
b. plowed agricultural fields
c. removal of natural vegetation
• Results in brown, cloudy water
• Decreases the amount of sunlight that
penetrates the water, decreasing
Thermal Pollution and Water
• When human activities cause a big change in
the temperature of the water
• Most common cause – steel mills and electric
power plants
• Solution
a. cooling towers
Water Regulation
• Clean Water Act – 1972
a. maintains chemical, physical, and biological
properties of natural water
b. defines acceptable limits of various pollutants
c. issues permits to industries on amounts of
pollution allowed to be discharged into water
• Safe Drinking Water Act
a. includes groundwater contamination
b. sets national standards for safe drinking
c. establishes “maximum containment levels (MSL)”
for 77 different substances in both surface
and groundwater