Contact Clarifiers in Drinking Water Treatment Processes

Abstract

The article deals with the issues of resource-saving technology in the preparation of drinking water on contact clarifiers. One of the methods of water purification from coarse and colloidal contaminants is the method of contact coagulation using aluminum sulfate coagulant. It is advisable to use contact clarifiers in single-stage treatment schemes for low-turbid colored and cloudy-colored waters, when the total content of suspended solids in the water entering the contact clarifiers, including the suspension formed as a result of introducing reagents into the water, does not exceed 150 mg/l. With a higher content of suspended matter in water, the water consumption for washing contact clarifiers increases sharply. To intensify the preparation of drinking water on contact clarifiers, a resource-saving technology is proposed using contact clarifiers using a modified aluminum sulfate coagulant solution, which makes it possible to: reduce the consumption of coagulants used in water purification, improve the quality of water clarification by weighing substances, and reduce the cost of water treatment. Theoretical prerequisites for improving the operation of contact clarifiers with a modified coagulant solution are considered. The use of a modified coagulant solution allows, without deteriorating the quality of water clarification, to reduce the calculated doses of the coagulant by an average of 25-30%, which confirms the feasibility of using a modified aluminum sulfate coagulant solution when clarifying water on contact lights. It has been established that the treatment of clarified water with a modified aluminum sulfate coagulant solution during contact coagulation makes it possible to reduce the residual aluminum content in clarified water by an average of 50-60%, the quality of water purification in terms of bacteriological and hydrobiological indicators is much higher than when treating water with a conventional coagulant solution.