Anaerobic Biological Treatment of Saline Municipal Wastewater by UASB

In this paper, saline wastewater was treated by using the UASB anaerobic reactor. The hydraulic retention time (HRT) of the reactor was controlled at 12 h. Research results shows that, the anaerobic activated sludge can effectively treat the saline wastewater. When the influent salinity was 1%, the corresponding COD removal rate of the reactor was 83.3%. In the following study, the influent salinity increased to 2% and 3% step-by-step. The result shows that the COD removal efficiency of the reactor changed little. The COD reduction of the reactor was 87.6% when the influent salinity was 2%. The COD removal rate changed to 85.2% when the influent salinity increased to 3%. The removal rate of NH4+-N and PO43-P also changed little when the influent salinity of the reactor increased form 1% to 3%. It shows that anaerobic activated sludge has good ability of salt tolerance.