[A submerged dynamic membrane bioreactor for domestic wastewater treatment]

The dynamic membrane forming on the surface of 0.1 mm Dacron mesh was utilized instead of static membrane, e.g. hollow fiber membrane, to develop a submerged dynamic membrane bioreactor (DMBR). The DMBR had high quality effluents when treating domestic wastewater at HRT = 3.5 h. The dynamic membrane could work steadily at a pressure no more than several centimeters water head drop. The highest SS concentration in the effluents was 4.05 mg/L, whereas the measured SS concentrations were zero in most circumstances. At condition of MLSS = 7000-8000 mg/L, the effluent head drop was only 5.8 mm when flux = 14.9 L/(m2.h), and it had little change during a continuous run for 27 days. The dynamic membrane averagely removed 28.74% of COD and 36.9% of TOC in the supernatant of the mixed liquor. The DMBR could remove NH3-N more than 96% when DO in the mixed liquor was no less than 2-3 mg/L.