| abstract |
Compositions useful for coagulating finely divided solids in turbid waters are prepared by mixing or blending together inorganic water soluble compounds such as aluminum chloride, aluminum sulfate, ferric chloride or ferric sulfate and water soluble organic positively charged polymeric coagulants having an average molecular weight of at least 2000 which is polydiallyl dimethylammonium chloride polymer. The compositions are especially useful for treating low turbidity waters, for example, waters having a turbidity of 20 NTU (nephelometric turbidity units). |