Membrane-coupled methanogenic and facultative Bioreactor in wastewater treatment

Abstract

This paper evaluates the feasibility of a membrane-coupled methanogenic and facultative bioreactor (MCMFB) system in treating the wastewater from the liquid crystal display (LCD)-related industry. The treatment unit is comprised of an anaerobic (methanogenic) and an aerobic reactor. The hollow fiber membrane module (0.036 mu m) was submerged in the aerobic reactor for solids/liquid separation. An average 80% COD removal was achieved in the anaerobic reactor when the volumetric loading reached 7.2 kg COD/m(3) per day. The effluent of the anaerobic treatment was fed into the aerobic-membrane tank to treat the residual COD. The mixed liquor suspended solids of the aerobic tank was 7000 mg/L with an average F/M of 0.14 g COD/g SS per day, and the removal efficiency of the aerobic tank was 90% in average. The transmembrane pressure and the flux of the membrane remained stable during the entire period of the 140-day operation without any backwash or chemical wash, indicating the applicability of the MCMFB system on treating the targeted wastewater.