Improving natural water purification with the use of new generation chemicals

Summary

The main aspects of natural water purification with coagulation are considered. The data on the composition of the surface public water supply sources in the area of Petropavlovsk-Kamchatsky are presented. The average molecular weight of humus substances present in natural waters is determined. The results of experimental studies of using new generation coagulants and flocculants in natural water purification at the water treatment facilities of MUE «Petropavlovsk Vodokanal» are presented. The action of coagulants: aluminium sulfate, aluminium hydroxychloride and aluminium oxychloride was studied. It was stated that the maximum efficiency of color removal from natural water in the Petropavlovsk-Kamchatsky environment is provided by the use of aluminium sulfate and aluminium hydroxychloride; whereas the use of aluminium oxychloride was less efficient. The efficiency of turbidity removal when using all the three coagulants was high – 70–100%. Praestol 650 TR and Praestol 2515 TR flocculants at mutual dose testing improve the efficiency of color removal: Praestol 2515 TR – from 49–66 to 63–100%. The use of flocculants provided for improving the floc formation rate, floc size, floc sedimentation rate and sludge volume. To introduce the new advanced coagulant at the water treatment plant the coagulation process testing with the use of aluminium sulfate in combination with the flocculant is required. To eliminate possible formation of problem chlororganics before the coagulant takes effect and humus settles special attention shall be paid to the sodium hypochlorite injection point when coagulating high-colored water.

Key words

turbidity , chromaticity , coagulation , flocculation , natural water , flocculation , water purification efficiency