Comparative Study Of Operational Efficiency Between Single MBR Process And Enhanced PAC-MBR Process

The Pharmaceutical and personal care products(PPCPs)have been checked out in water body frequently with the development and improvement of analysis and detection technology,although the concentration of them is low and kept at ng/L-ug/L,their potential hazards have attracted people's attentions.However,since the instruction and properties of these drugs is not same,although many different technologies have been used to remove them,the removal efficiency did not achieve the desired results.At present,the enrichment and breeding of microorganism is enhanced,the removal effect of refractory organics is improved and the effluent water quality become better in membrane bioreactor(MBR)due to its direct solid-liquid separation with membrane filtration,so that it has drawn many attentions.In this study,the powered activated carbon(PAC)was added into MBR to improve the biodegradation of microorganisms,mitigate the membrane fouling and enhance the removal efficiency of PPCPs drugs.At first,the PAC was added into MBR to study whether it will affect its operating efficiency,two reactors were set up on the same condition.The results showed that the added PAC could provide a better growth site for microorganisms as a carrier so that the biodegradation was enhanced,the removal rates of organic matter,ammonia nitrogen,total phosphorus,total nitrogen was improved 8.22%?3.53%?6.07% and 2.54% respectively.In addition,it was found that the added PAC was conducive to the reduction of protein and polysaccharide and it could a factor to control the membrane fouling.The ibuprofen and naproxen were chosen as target matter to study the drugs removal efficiency and operational efficiency of PAC-MBR mixed system and single MBR system under different dissolved oxygen,which were two typical non-steroidal anti-inflammatory drugs.The experimental results showed that the organic matter removal rates presented a decreasing trend in two systems,but that of PAC-MBR system was lower than that of MBR system,the ammonia nitrogen removal rates were not affected and the total phosphorous removal rates decreased followed by increasing.Two drugs were treated as organic matter to degrade by microorganisms,however,the removal rates of them presented a increasing trend under different dissolved oxygen due to the increase of sludge concentration in reactor.In addition,the concentration change of protein and polysaccharide was analyzed.The change tendency of protein was not same in reactor and that maybe related to the biological powered carbon(BAC)which owned good floc structure,but the change tendency of polysaccharide was not affected.Therefore,the PN/PS ratio showed a decreasing trend.