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SEWAGE DISPOSAL

Ability of anaerobic bacteria to purify the organic matter is used in the sewage disposal system of cities.The faeces are stored in covered reserviors and allowed to purify. The solidmatter is decomposedinto liquidy sludgewhich is passed through coarsefilters. The effluent is finally purified and drained out into the river or used as fertilisers in the fields. The common bacteria involved in sewage disposal are -- Coliforms (E.coli),Streptococci,Clostridium, Micrococcus,Proteus,Lactobacillus, etc.