Chapter 5 Air and Water Resources Finding Pollution Solutions Section 3 Notes 5-4

Reducing Air Pollution Clean Air Act: development of air pollution control technologies Scrubber: removes pollutants from air with a stream of water droplets Pollutants fall into a container after being dissolved in the water Filters: trap particles of soot and ash Catalytic Converter: device on vehicles Reduces carbon monoxide emissions by forming less harmful carbon dioxide and water

Reducing Air Pollution CFC substitutes 1987 many nations agreed to stop using CFCs by 2000. Refrigerators and air conditioners use less harmful substances New ways to create plastic foam without CFCs

Cleaning Up the Water Sewage Treatment To reduce water pollution: Treat wastes so they are less harmful Find substitutes for pollutants Sewage Treatment Primary Treatment: removes solid materials from wastewater Water passes through filters Solids are held in tanks and particles settle out

Cleaning Up the Water Secondary Treatment: bacteria break down solid wastes Water is treated with chlorine to kill disease causing organisms Arcata, CA Wastewater flows into ponds with algae Algae breaks down sewage Water moves to marshes with cattails and bulrushes to clean the water Areas are also for habitats for fish and birds Also areas for bike riding and trails for recreation

Cleaning Up the Water Oil and Gasoline Oil spills can be cleaned up with bacteria Bacteria eat the oil and reproduce as long as there is food They die off as soon as their food disappears Big oil spills affect the wildlife before the bacteria can restore the ecosystem Gasoline spills are hard to clean up Soil can be removed However, if gasoline reaches the groundwater…much worse! Water has to be pumped out and cleaned Then it can be put back into the ground

Cleaning Up the Water Industrial Chemicals Farming Chemicals Industries can recycle their wastes They save money and reduce pollution Industries can change how they produce their product Use less water or create less harmful wastes Farming Chemicals Finding alternatives to pesticides and fertilizers DDT (dichloro-diphenyl-trichloroethane) 1972 DDT usage was stopped Today it is labeled as a probable human carcinogen Stays in an organism for a long time

What can you do? Little changes can make a big difference Walk or ride a bike Save electricity by turning off lights and other devices Carpool Buy a more fuel efficient vehicle Don’t pour chemicals down the drain Don’t put old medicines in the toilet