EUTROPHICATION_WATER POLLUTION_Dr. SABITHA SOMAN

Eutrophication in water pollution

1. EUTROPHICATION

2. EUTROPHICATION The process of increase in the nutrients of waters and the resultant increased algal productivity is called eutrophication. eutrophos – rich Eutrophic – rich in nutrients Oligitrophic – poor in nutrients First used these terms in limnology by Naumann (1919)

3. PROCESS OF EUTROPHICATION NATURAL EUTROPHICATION Natural run-off Fall of leaves and twigs from surrounding vegetation Submergence of nearby terrestrial vegetation Rain fall and bird droppings etc. Steps in natural eutrophication Oligotrphic lake – natural process – algal growth- die and decomposition-unlock nutrients to fresh algal growth- each cycle, nutrients increases-increased organic matter disturbs nutrient cycles – thickness of bottom sediments increases, forms swamps, marshes etc.- extinction of the water body in long run.

4. Accelerated or cultural eutrophication Increased supply of nutrients by human activities- discharge of domestic sewage, industrial wastes, agricultural and urban run off. Algal blooms and eutrophication Ageing of lakes- reduced extinction time due to accelerated eutrophication

5. Effects of eutrophication Physico -chemical- P=R, pH, DO, odour, cloudy Biological – algal bloom, overload of organic matter, destruction of flora and fauna.

6. Sources of nutrients Rainfall and Atmospheric Deposition Urban and Rural run-off Agricultural Run-off Domestic sewage Industrial wastes Water Fowl

7. Control of eutrophication A. Preventive measures Diversion of nutrients from lakes Removal of nutrients from waste waters Zoning and watershed management B. Curative measures Flushing out of polluted water by nutrient poor water Removal of locked-up nutrients Dredging of sediments Covering of sediments Oxygenation and mixing Nutrient inactivation