EVALUATION OF HOLLOW FIBER MEMBRANE BIOREACTOR EFFICIENCY FOR MUNICIPAL WASTEWATER TREATMENT

The membrane bioreactor technology has been proven to be a single step process in efficient treatment ofwastewater, either directly or after pretreatment by reverse osmosis. In this study, a pilot scale experimentwas studied to treat a synthetic municipal wastewater sample. The aerobic reactor with a submergedmembrane used in this work was continuously aerated for organic matter oxidation, nitrification andphosphorous uptake as well as for fouling control. The mixed liquor was recycled from the aerated zone
to the anoxic zone for denitrification. The membrane had a nominal pore size of 0.1 μm and a filtrationarea of 4.0 m2. The performance of submerged membrane bioreactor was examined in order to determinethe removal efficiency of organic compounds and nitrogen in different solid retention times (10, 20, 30,and 40 days) under a continuous inflow of the synthetic municipal wastewater. Results indicated that thesubmerged membrane bioreactor could efficiently remove the pollutants. Average removal rates of
chemical oxygen demand, total Kejeldahl nitrogen removal, total nitrogen and phosphorous reached to ashigh as 99.3%, 98.1%, 85.5%, and 52%, respectively. Furthermore, concentrations of nitrate and nitrite inthe last stage were well reduced and reached to 5.3 and 0.047 mg/L, respectively.