COMPARATIVE ANALYSIS OF EFFECTIVENESS OF POLVAK 15/72 AS A COAGULANT FOR DRINKING WATER PRODUCTION

Abstract

New coagulant Polvak 15/72 consisting of aluminum hydroxychloride with a pure Al₂O₃ content of at least 15.3 wt % was investigated as a possible highly effective agent for discoloration, clarification, and cleaning the natural freshwater to produce high-quality drinking water. Water was taken from the river of Dnipro during the winter-summer period of 2022. A 20 mg dm^-3 coagulant concentration showed sufficient water cleaning effectiveness, and brought its chromaticity, turbidity, permanganate oxidizability, aluminum and iron contents within the sanitary limits. This result has been achieved using a coagulant that does not consist of Fe (for which the toxicity is higher than that of Al) and less Al than in the widely used Polvak-68. The effectiveness of removing trihalomethanes (THM, mostly chloroform) by Polvak 15/72 is insufficient, and additional non-polar adsorbent or the use of a chlorine-free water disinfection technology is required to keep the content of THM within the sanitary limits.