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Chapter 22. Water Pollution. Types of Water Pollution. Explosion in algal, bacteria, & decomposer populations. ↑ Enrichment. Fish kills. ↑ Biological oxygen demand. ↓ Oxygen levels in water. Sewage. Types of Water Pollution.
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Chapter 22 Water Pollution
Types of Water Pollution Explosion in algal, bacteria, & decomposer populations ↑Enrichment Fish kills ↑Biological oxygen demand ↓Oxygen levels in water • Sewage
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 Fecal coliform test • Disease-Causing Agents • Monitoring for Sewage
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
Lead affects practically all systems within the body. It is a powerful neurotoxin that interferes with the development of the brain and central nervous systems as well as the kidney and blood-forming organs and can cause a wide range of health effects. Impacts on cognitive thinking, memory, attention, language, and fine motor and visual spatial skills have been seen in children exposed to methylmercury in the womb. Elemental (metallic) mercury primarily causes health effects when it is breathed as a vapor where it can be absorbed through the lungs.
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 http://www.compulsivetraveler.tv/videos/408-Ganges-River-Pollution
Water Quality Today - Water contaminated with disease-causing organisms - Led to cholera and diarrhea outbreaks • Two boys collect water from an unsafe source far from their home in Kwale district
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 Collected from reservoir or ground water. • Purification of Drinking Water • General process:
Improving Water Quality Water treated • Purification of Drinking Water • General process:
Improving Water Quality • Purification of Drinking Water • General process: Distributed to customers Wastewater 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 (1974) • set the maximum contaminant level for drinking water • Clean Water Act ( 1972) • pertained to improving quality of rivers, lakes, aquifers, estuaries, and coastal waters • reduce direct pollutant discharges into waterways, finance municipal wastewater treatment facilities, and manage polluted runoff.
Laws Controlling Water Pollution • Case-in-Point:Water Pollution in the Great Lakes http://www.wkyc.com/video/default.aspx?aid=65282
Laws Controlling Water Pollution • Laws That Protect Groundwater • Safe Drinking Water Act • The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources: rivers, lakes, reservoirs, springs, and ground water wells. (SDWA does not regulate private wells which serve fewer than 25 individuals.) • Resource, Conservation, and Recovery Act • enacted in 1976, is the principal Federal lawin the United States governing the disposal of solid waste and hazardous waste.