Purificn. of urban waste waters ­ using oxidn.­redn. and coagulatio -­flocculation stage

Purificn. of urban waste waters by destroying organic and inorganic impurities to ensure that resulting residual matter should conform to normal effluent standards. This is achieved by an oxidation reduction stage over a bed of waste cast iron and alloys. In the following coagulation-­flocculation stage ions generated in
the first stage are employed.