POLLUTION Origin of Air, Water and Soil pollution. Rd. chpt 27, 28 in Atwaroo Ali for supplemental notes
What is pollution? • Pollution is the contamination of an environment. To cause harm to an are of natural environment. • Pollution is caused by man’s impact and growth and his improper disposal of waste materials generated. • Industrialisation has had a great impact on the type and volume of pollutants released. • Primary, secondary, tertiary and quaternary economic activity which is a sign of man’s success has added to the effect of pollution
Primary activity: farming, fishing, mining • Secondary: manufacturing, construction • Tertiary: administrative, retail, transport • Quaternary: technology and information services.
Types of pollution • It is classified into: • Land/soil pollution • Air pollution • Water pollution
Land/ soil pollution • Land pollution is the contamination of land spaces or soil. Has commercial, agricultural, industrial, domestic sources • Instances when this occur are: • Agricultural waste such as insecticides and pesticides which are used excessively and leach into the soil. These products not only affect the target organism but others as well.
The soil chemistry is changed and this can affect growth and survival of plants and animals. • Non-biodegradable waste originating from household and industrial products. These stay a very long time in the environment as they either can be broken down or they take very long .e.g. plastics, glass metals
Land pollution • Littering and the development of landfills affect soil chemistry. • Bio degradable materials : The materials that are able to break down naturally into harmless simpler forms by actions of micro-organisms. E.g. paper, some plastic, textiles.
Chemical and nuclear plants • Industrial factories • Oil refineries • Human sewage • Oil and antifreeze leaking from cars • Mining • Littering • Overcrowded landfills • Deforestation • Construction debris
Water pollution • Contamination of water resources i.e. oceans, lakes, rivers by harmful substances. Also affects drinking water • Water comprises 70% of earth’s surface. Is a very important resource for plants and animals • Point source- derived from discrete location ( pipe or drain) and non-point source- no single point of origin, contaminants are spread over a larger area. ( leaching of fertilizer)
Sources of water pollution • Non-biodegradable waste • Insecticides, pesticides leaching into groundwater • Oil spill • Hot water from industries • Untreated waste and nutrient accumulation • Toxic chemicals
Non-biodegradable waste • Covers surfaces or obstructs current pathways preventing or poisoning organisms. • Clogs waterways restricting movement of aquatic organisms
Insecticides and herbicides • Sourced from agriculture lands. • Sprayed or leached into water ways • Encourages eutrophication of water ways • Availability of nutrients encourages algal growth as well as microbial growth • More O2 is used up than is replaced in water and algal bloom prevents sunlight entering water. • Reduces oxygen content can cause asphyxiation lead to death of organisms.
Oil spills • From tankers and pipelines • Covers surface of water • Coats surface and feathers of water based organisms: fish, water birds • Clogs pores and orifices leading to limiting movement and suffocation. • Use berms , floating devices which contain oil spills. calcium carbonate based chemicals which break down oil into simpler harmless molecules.
Hot water • Derived from industrial sources where water is used for cooling. • Can kill organisms due to high temperatures and also change the abiotic conditions of habitat. • Cooling of water before release
Untreated waste and nutrient accumulation • Untreated sewage also adds to algal bloom and eutrophication • Bacteria introduction to water sources can cause diseases such as salmonella , diarrhea and cholera to spread. • Nutrients: NO3, NO2 leaching into soil
Untreated waste and nutrient accumulation • Treatment of waste and sewage properly before release into environs- septic tanks Ozone wastewater treatment to kill bacteria in sewage. • Reduce leaching into waterways, controlled fertilizer use or use of environ friendly organic fertilizers • Denitrification bacteria used to reduce NO3 leaching into waterways.
Toxic chemicals • Source includes industrial plats where heavy metals, acids and organic mercury is released • These are poisonous to orgs • Screen and proper treatment of industrial waste before release into environs.
Air pollution • Smog, acid rain, CFC’s (chlorofluorocarbons), particulate matter , noxious gases all contribute to air pollution.
Contributors to air pollution: • Automobile emissions • Tobacco smoke • Combustion of coal • Acid rain • Noise pollution from cars and construction • Power plants • Manufacturing buildings • Large ships • Paint fumes • Aerosol sprays • Wildfires • Nuclear weapons
HW. : • Make notes on the effects of pollutants on environment and methods to treat or control pollution. Ref Chpt 28
What activities have negative impacts on the environment • Deforestation: removal or clearance of naturally occurring forests. • Overfishing: blast fishing, trawling • Coral reef and mangrove destruction
Activities with a positive impact on environment • Aforestation; planting trees on land that has not been a forest before or not in recent times. • Reforestation: replanting trees in areas where they were once removed • Conservation via three R’s: • Reduce • Reuse • Recycle
References • http://www.water-pollution.org.uk/ • http://www.water-pollution.org.uk/lawsandconventions.html • http://www.greenstudentu.com/encyclopedia/pollution