Impact of polyhexamethylene guanidine hydrochloride on the process of coagulation treatment of river waters

The paper has investigated flocculation capacity of polyhexamethylene guanidine hydrochloride during joint treatment with aluminum sulfate of the Dnieper and Desna River water in the spring period. It has been shown that additives 1–5 mg/dm³ of the matter under study during coagulation treatment of the river waters improves the process of their clarification, increases the filtrate quality in terms of main indicators and makes it possible to reduce by 10–20 mg/dm³ the dose of the coagulant. A pronounced flocculation effect manifests itself when treating the waters in question by the doses of a polymer preparation respectively 3–5 and 2–3 mg/dm³. Polyhexamethylene guanidine (without a coagulant) ensures a standardized quality of the filtrate in terms of color and turbidity only when treating weakly stained water of the Desna River. It has been found that ≥ 99% of polyhexamethylene guanidine is retained by the medium of a sand filter.