Improving the quality of waste water treatment by flocculation

Abstract

Flocculation using polyacrylamides is one of the most promising methods of industrial wastewater treatment. The aim of our research was to estimate the efficiency of the use of new types of polyacrylamide-based flocculants for industrial wastewater treatment. The objects of the study were the wastewaters of the enterprise LLC “Saratov Chemical Plant of Acrylic Polymers “ACRYPOL” and several flocculants (water-soluble polymers) obtained on the basis of acrylamide, acrylic acid and chitosan. It was established that the optimal dose of nonionic flocculant H600™ was 5 mg/dm3. Industrial wastewater treatment efficiency was studied on two samples of weakly cationic flocculants (215-2 and 233-2) synthesized in a laboratory way, as well as on a sample of nonionic flocculant H600™. It was found that the tested flocculants had no significant effect on the pH value and the content of sulfate ions in water. Flocculant 233-2 with the highest chitosan content was the best in terms of chemical oxygen demand, dry residue and the amount of suspended solids. Flocculant 215-2 with the lowest chitosan content had a slightly worse performance. The worst of the tested flocculants was the nonionic H600™, which does not contain chitosan.