Research and evaluate on Wastewater Treatment of septic tank

As a sewage pretreatment unit, septic tank has played an important role in environmental pollution treatment. The quality of domestic sewage and the removal rate of various pollutant indices were analyzed after the treatment in the septic tank, through the investigation on the septic tanks of Chaohu City, located in Anhui Province, P R China. The results of the research indicated that the removal rates of COD, BOD₅, SS and TN were 41.23%, 32.86%, 30.07% and 10.54% respectively; concentration of NH₃-N and TP was increased. The removal rates of COD and BOD5 increased with the temperature rising, however, there was not significant change of removal rates in N and P. In addition, the biodegradability of the wastewater was depressed in septic tank. The results have provided the comprehensive evaluation of septic tank and the technical of the selection.