Authigenic Bio-dynamic Membrane Reactor Treatment Of Municipal Sewage Characteristics

The self-forming bio-dynamic membrane reactor (SFDMR) was equipped with a l00μm nylon mesh as filter material instead of a micro-filtration membrane in membrane bioreactor. We had observed the formation and recovery processes of SFDM, effects of pore sizes, flux and MLSS on the formation of SFDM. The artificial domestic wastewater was fed to the reactor to examine the long-term effect and the mechanism of treatment when HRT = 4h, flux = 20.8L m-2h-1 and MLSS = 4000mg/L. The paper discussed the impact of HRT on the treatment and the ability of anti-shock. The distribution of filtration resistance was accounted during experiment, and harnessing measure of fouling of membrane was also studied. Through the comparison between the CAS and MBR, we made technological and economic assessment on SFDMR.The experiment showed that a very good effect of removal could be seen using the SFDMR to treat domestic wastewater. System could work steadily 40 days at a pressure as low as 9mm water head drop. During the steady running, conclusion from the results of investigation was that SS concentration could not be monitored, turbidity of effluence was less than 5NTU, and the removal rates of COD and NH3-N were above 80% and 87% respectively. The self-forming bio-dynamic membrane could form in 48h, including cake layer and gel layer, and cake layer could form in l0min. the formation of gel layer was a slower process. Gel layer was composed by filamentous by SEM. The filtration resistance of SFDM was only 1.5xl0¹0m^-1, exponentially two or three times smaller than MBR. The resistance caused by cake layer contributed above 90% to the total filtration resistance of the SFDM. Aerating was conducted to control membrane fouling. When aerating time was 2min, flux could be resumed to 72%.