The impact of the sewer system rinsing on the wastewater composition

The paper presents the results of research on the influence of the operational rinsing of a sewer system on the composition of raw sewage, the effectiveness of the operation of the mechanical part of a wastewater treatment plant and changes in the technological parameters of the biological reactor. The results of the research have shown an increase in sewage pollution during the rinsing of the sewer system. The value of the COD indicator increased from 799 to 1306 mg/dm3, BOD5 from 538 to 1044 mg/dm3, and total suspended solids from 259 to 1508 mg/dm3. The calculations indicate that an increase in the concentrations of pollution during the rinsing of the sewer system requires a high working efficiency of the mechanical part of the wastewater treatment plant. With a low efficiency the volume of the biological reactor can increase even by 30%.