The Study Of Dynamic Membrane Bioreactor With Gravity Flow Treating Domestic Sewage

Compared with the traditional activated sludge process, the membrane biological reactor (MBR) has the advantages: less space occupancy, easily control, higher sludge concentration, higher oxygen transfer efficiency, better effluent and less excess sludge. However, the high cost of membrane module limit the application in practice, so combined with Chinese specific national conditions, low investment, higher efficiency, energy saving and easy to operate the sewage treatment technology is the direction of development in future. The subject of the use of dynamic membrane bioreactor(DMBR)with gravity flow treating domestic sewage can effective save the energy consumption, the use of cheap membrane material in a non-woven fabric membrane to reduce the cost of the membrane and reduce pollution; so the membrane bioreactor for treating the domestic sewage has an important practical significance.The research that the dynamic membrane bioreactor with gravity flow treating domestic sewage and the organic load, DO, pH and other factors change on the effect of system operation showed that COD, ammonia nitrogen, total phosphorus removal rate is very high, water can be achieved miscellaneous living standards; reactor has strong impact resistance capacity; DO and pH changes in a certain range the COD removal rate has no big impact, but ammonia to remove has a greater impact.In a study of the hybrid dynamic membrane bioreactor (HDMBR)with gravity flow treating domestic sewage showed fill in the fill ratio of 40% of the conditions, when the gravity-flow system of HDMBR reached steady state, the system for COD, ammonia nitrogen to remove the effect of is good , as a result of the role of membrane, the effluent COD concentration remained relatively low level, while the membrane does not retain for itself the role of ammonia; HDMBR system of the total phosphorus removal rate at the initial is well, but the late decrease; DO and pH in a certain changes in the scope the COD removal for basically no major impact, but a greater impact on nitrogen removal.Research shows that non-woven fabric as a membrane module to reduce the cost; areas in the biological response to precipitation, the study shows that after deposition of the lower effective concentration of the sludge which reduces the membrane fouling; aeration and membrane surface can be updated and pore recovery, and thus the recovery of membrane flux for a certain role to enhance, through the optimization of aeration intensity can be drawn, the aeration capacity of 3m~3/h when the amount of aeration for the best; compared HDMBR with DMBR the flux studies, HDMBR contrast can be DMBR than the slow decline in flux, and the late HDMBR flux can be stabilized at a higher level.Through the research of the condition about the membrane cleaning, using the following process the membrane flux can restore well: Running water counter-flushing—alkali washing (0.2mol/LNaOH) 1 hour—acid washing (0.1mol/LHCl) 1 hour.The research showed the test combined with Chinese specific national conditions, low investment, high efficiency, energy saving and easy to operate the sewage treatment technology is the future direction of development.