EVALUATION OF HOLLOW FIBER MEMBRANE BIOREACTOR EFFICIENCY FOR MUNICIPAL WASTEWATER TREATMENT

Abstract

The membrane bioreactor technology has been proven to be a single step process in efficient treatment of
wastewater, either directly or after pretreatment by reverse osmosis. In this study, a pilot scale experiment
was studied to treat a synthetic municipal wastewater sample. The aerobic reactor with a submerged
membrane used in this work was continuously aerated for organic matter oxidation, nitrification and
phosphorous 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 filtration
area of 4.0 m2. The performance of submerged membrane bioreactor was examined in order to determine
the 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 the
submerged membrane bioreactor could efficiently remove the pollutants. Average removal rates of
chemical oxygen demand, total Kejeldahl nitrogen removal, total nitrogen and phosphorous reached to as
high as 99.3%, 98.1%, 85.5%, and 52%, respectively. Furthermore, concentrations of nitrate and nitrite in
the last stage were well reduced and reached to 5.3 and 0.047 mg/L, respectively.