Embed Size (px)
Citation preview
Water Pollution
Chapter 22
Types of Water Pollution
Sewage
↑ EnrichmentExplosion in algal, bacteria, & decomposer populations
↑ Biological oxygen demand
↓ Oxygen levels in water
Fish kills
Types of Water Pollution
Effect of sewage on dissolved oxygen and biological oxygen demand
Types of Water Pollution
Eutrophication: An Enrichment Problem
Oligotrophic lake
Types of Water Pollution
Eutrophication: An Enrichment Problem
Eutrophic lake
Types of Water Pollution
Disease-Causing Agents
Types of Water Pollution
Disease-Causing Agents
Monitoring for SewageFecal coliform test
Types of Water Pollution
Sediment Pollution
Low sediment load
Types of Water Pollution
Sediment Pollution
High sediment load
Types of Water Pollution
Inorganic Plant and Algal Nutrients
The Dead Zone in the Gulf of Mexico
Types of Water Pollution
Organic Compounds
Types of Water Pollution
Inorganic Chemicals
• Lead
• Mercury
Types of Water Pollution
Radioactive Substances
Thermal Pollution
Water Quality Today
• Point source pollution
(e.g., cyanide spill)
• Nonpoint source pollution
(e.g., fertilizer runoff from agriculture fields)
Water Quality Today
Water Pollution from Agriculture
• 72% of water pollution in rivers attributed to agriculture
• Chemical pesticides may leach into soil and then into water.
Water Quality Today
Municipal Water Pollution
Water Quality Today
Industrial Wastes in Water
• Problems depend upon industry– Food processing high BOD– Paper mills toxic compounds & sludge
• Many US industries now treating wastewater
(some can recover merchantable products)
Water Quality Today
Groundwater Pollution
Water Quality Today
Water Pollution in Other Countries
• Lake Maracaibo, Venezuela
Water Quality Today
Water Pollution in Other Countries
• Po River, Italy
- Equivalent of the Mississippi River,
- Sewage, industrial wastes, sediment
- >16 million Italians depend on the river for drinking water
- Pollution is so bad, swimming has been suspended in parts, jeopardized tourism and fishing
Water Quality Today
Water Pollution in Other Countries
• Ganges River, India
Water Quality Today
Water Pollution in Other Countries
• Kwale, Kenya
- Water contaminated with disease-causing organisms
- Led to cholera and diarrhea outbreaks
Water Quality Today
Water Pollution in Other Countries
• Arsenic Poisoning in Bangladesh
- In 1980s world health organizations, sponsored digging wells
- Unfortunately, naturally occurring arsenic led to wide-spread poisoning
Improving Water Quality
Purification of Drinking Water
General process:
Collected from reservoir or ground water.
Improving Water Quality
Purification of Drinking Water
General process:
Water treated
Improving Water Quality
Purification of Drinking Water
General process:
Distributed to customersWastewater collected as sewage
Improving Water Quality
Purification of Drinking Water
General process:
Sewage treated
Improving Water Quality
Purification of Drinking Water
Purification issues:
• The Chlorine Dilemma
• Fluoridation
Improving Water Quality
Municipal Sewage Treatment
Primary and Secondary Sewage Treatment
Improving Water Quality
Municipal Sewage Treatment
Effectiveness of primary, secondary, and tertiary sewage treatment
Improving Water Quality
Municipal Sewage Treatment
• Major problem associated with wastewater treatment is disposal of sludge
• Can be used as fertilizer, but there may be health risks (e.g., heavy metal poisoning)
• Used to be dumped in ocean, that is now banned
• Currently, most dumped in landfills
Improving Water Quality
Individual Septic Systems
Septic tank
Improving Water Quality
Individual Septic Systems
Drain field
Laws Controlling Water Pollution
• Safe Drinking Water Act
set the maximum contaminant level for drinking water
• Clean Water Act
pertained to improving quality of rivers, lakes, aquifers, estuaries, and coastal waters
Laws Controlling Water Pollution
Case-in-Point: Water Pollution in the Great Lakes
Laws Controlling Water Pollution
Laws That Protect Groundwater
• Safe Drinking Water Act
• Resource, Conservation, and Recovery Act
