Treatment of Low Strength Wastewater Using Bench-Scale Anaerobic Membrane Bioreactor

Experiments were conducted to evaluate the performance of a bench scale anaerobic membrane bioreactor (AMBR) treating synthetic low-strength wastewater. The following parameters were monitored: pH, chemical oxygen demand (COD), and five day biochemical oxygen demand (BOD5) for the bioreactor influent, effluent and mixed liquor (biomass). The bioreactor provided removal of COD but BOD5 did not meet the strict effluent standards required by USEPA. Most of the removal was done by the membrane and not by biological means. Membrane flux was measured frequently to assess fouling. Supplemental analysis of nutrients included nitrate, total nitrogen (TN), and total phosphorous (TP). There was no nutrient removal, as was expected. Additionally, total suspended solids (TSS) and volatile suspended solids (VSS) were measured to monitor the mixed liquor biomass density. Microscopy was conducted on the mixed liquor to characterize the floc structure of the microbial community.