Selection of efficient chemicals for low turbid water purification from surface water sources

Summary

The results of laboratory study of selecting chemicals and optimal dosage for the purification of low turbid water of the Saratov water reservoir are presented. The laboratory tests of aluminium polyoxychlorides (14 kinds) and aluminium sulfate (16 kinds) were carried out. Coagulants manufactured by domestic and foreign manufacturers were studied. The optimal dosages of coagulants and flocculants were determined. Two of the coagulants studied were selected that could ensure the maximum degree of water clarification at the minimum concentration of residual aluminium and permanganate value in drinking water. It was stated that water treatment exclusively with coagulants with subsequent sedimentation and filtration ensured meeting the state drinking water standard. The results of the experimental studies of coagulation of low turbid water of the Saratov water reservoir showed that the maximum water clarification was achieved by sedimentation at the optimal coagulant dosage of 9.6 mg/dm³ for Al₂O₃ and 0.2 mg/dm³ flocculant dosage. At that the pollution loading on filters is reduced and the filter run increases.

Key words

turbidity , chromaticity , coagulant , flocculant , residual aluminium , permanganate oxidizability , low turbid water