Chapter 11-3 Water Pollution

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Water Pollution

• Introduction of chemical, physical or biological agents that adversely affect the organisms that depend upon that water

Point-source versus Nonpoint-source pollution

• Point-source can be traced to a source

• Nonpoint –source comes from many different sources that are often hard to identify

                                                                                  

Pathogens

• Parasites, bacteria and viruses that cause illness in living things

• Many spend part of their life cycle in water

• Pathogens carried by water cause more human deaths than any other environmental problem

Cholera

• Acute diarrhea• Caused by bacteria• Infected food water,

shellfish• Heat kills cholera

bacteria

Dysentery

• Several bacteria and protozoa responsible

• Vomiting, severe diarrhea

• Cause water contamination

• Heat kills most of these

Typhoid Fever

• Salmonella Thyphi• Only people carry the

bacteria• Shed in feces• Vaccination available• Boil it , cook it, peel it

or forget it

Schistosomiasis

• Caused by microscopic worms

• Enters through the skin of people who walk in infected water

• Attacks liver, urinary bladder, and intestines

Schistosomiasis

• Africa, Middle East, Egypt

• 100 million people affected

• 1 million deaths annually

• Aswan Dam

WAPI 158 degrees F

Malaria

• Protozoan• Transmitted by

mosquito• The mosquitoes breed

in standing water• 800 million affected• 1 million deaths

annually

Organic Matter

• Animal and plant remains, feces etc.

Organic Chemicals

• Pesticides, fertilizer, gasoline, oil etc..

• Runoff from farmlands

• Organic pesticides, herbicides and fertilizers

Inorganic chemicals

• Acids, bases, salts, etc..

Heavy Metals

• Dangerous heavy metals include: Mercury, lead, cadmium, nickel, chromium and Slipknot.

Physical Agents

• Heat and suspended solids

Wastewater

• Contains waste from homes or industry

Treatment

• Primary – filtration and settling. Gets the big stuff out

Secondary

• Aeration

• Second settling tank

• Chlorination to kill pathogens

Artificial eutrophication

• Caused by fertilizer run-off or other organic wastes

Thermal Pollution

• Heat can be a type of water pollution

• Power Plants

• Reservoirs

Groundwater Pollution

• Any polluted surface water can become polluted groundwater

• Very hard to clean up

Ocean Pollution

• Oil spills – Exxon Valdez 1989

• Plastics

Cleaning up water pollution

• Clean Water Act of 1972

• Safe Drinking water act of 1996