water pollution chapter 22. types of water pollution sewage ↑ enrichment explosion in algal,...

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