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Describe causes and methods of controlling water pollution.

Answer Text:
• Agrochemicals for example, fertilizers cause eutrophication leading to increase in animal population
• Silting makes water surfaces shallow and silt clogs stomata and gills of fish reducing rates of photosynthesis and gaseous exchange. It also leads to reduction of algae which causes reduction of consumers that is, animal population
• Industrial and domestic wastes contain toxic materials which kill producers and other organism while oily substances in wastes may clog gills of fish and may change pH of water oxygen solubility is also reduced by oily surfaces
• Untreated sewage and effluents where decomposition or organic matter in sewage reduces
oxygen supply and sewage provides food for bacteria increasing their population and demand for oxygen thus depriving fish of oxygen.
• Human feaces causes eutrophication, carbon IV
oxide produced by decomposition of faecal matter changes pH of water interferes with photosynthesis and may clog fish gills or block light penetration which interferes with producers thereby decreasing productivity.
• Dumping of chemicals from industries with toxic
pollutants which kill organisms
• Spillage of oil and chemicals block oxygen and
kill organisms
• Discharge of water from industries into water body
where high temperatures reduce amount of oxygen in the water causing organism to suffocate and die
• Untreated sewage may lead to outbreak of epidemics
Control of water pollution
-pollution caused by domestic effluents may be controlled by treating domestic waste, using biotechnology, banning the use of phosphate-based
detergents, using plastic pipes instead of those made from lead, recycling garbage, using biodegradable detergents.
- Pollution caused by industrial waste may be controlled by treating/cooling industrial waste, carrying out environmental impact assessment before establishing industries
- Oil spillage may be controlled by cleaning spilled oil biotechnology and penalizing the industry individual or companies which cause oil spills/water pollution
- Pollution caused by agrochemicals may be controlled by using mechanical control of weeds, biological control of weeds and pests, biodegradable organic fertilizer herbicides,insecticides pesticides,
organic farming educate farmers on the use of correct amount of agrochemicals
- silting may be controlled by appropriate farming
practices, contour farming, reafforestation, building gabions and terracing