" Any human activity that impairs the use of water as a resource may be called water pollution. with expoloding population and increasing industrialisation and urbanisation,water pollution by agricultural,municipal and industrial sourcs has become a major concern for the welfare of mankind "

classification of water pollution :

the various type of water pollution can be broadly classifide into the following five major categories :

1>> organic pollution

  the organic pollution may be further categorized as follows :

    a>>oxygen demanding wastes

     b>>disease-causing wastes

    c>>synthetic organic compounds

    d>>sewage and agridultural run off

    e>>oil

2>>inorganic pollutants

   various metal and metallic compounds form anthropogenic activitis add up to thair natural bacground levels in water.some of these trace metals play essential roles in biological processes , but at higher concentrations, thay may be toxic to biota.

3>>suspended solids and sediments

  the organic matter content in sediments is generally higher then that in soils . sediments and suspended particles exchange cations with the surrounding aquatic medium and act as repositories for trace metals such as Cu,Co,Ni,Mn,Cr and Mo.

4>>radioactive materials

   the radioactive water pollutionts may originate form the following anthropogenic activities :

*>>mining and processing of ores , e.g. ,uranium tailings

5>>heat

  if the pollutannt concentration in the receiving waters is not within the acceptable limits , adequate steps must be taken to minimize or remove them by suitable treatment techniques ,

e.g. , oxidation ,biological,filtration etc.