Increasing the efficiency of sedimentation tanks for drinking water treatment

Abstract

The sedimentation process is of great importance in the purification of drinking water. To improve the efficiency of horizontal sedimentation tanks for drinking water treatment, it is recommended to use thin-layer sedimentation tanks. Experimental studies of the effectiveness of water distribution methods in a thin-layer sump were carried out on model and semi-industrial installations. The settling tank model was made of organic glass at a scale of 1:12. In accordance with the scale factor and the Froude criterion, Qo, tp, Vp were determined. An analysis of the research results showed that for all values of m, the closest approximation of Vph to Vr was achieved when the upper edges of the plates were located along a curve calculated using a method that considers the water flow in the distribution volume as a flow of variable mass. KOI at the same time exceeded 90%. It has been established that with a 3-4-fold increase in the hydraulic load of the sump with the proposed method of water distribution, its KOI decreases slightly (from 92-95% to 74-85%), while with the location of the upper edges of the plates along an inclined or horizontal straight line, the KOI decreases from 68-83% to 15-20%. For the conditions of production operation of sedimentation tanks, where, depending on the time of day, year and production technology, the amount of drinking water can vary widely, this circumstance is of particular importance. As a result, the efficiency of the drinking water treatment process will be increased.