Sludge-Based Activated Carbon Enhanced MBR Process For Treatment Of Urban Black-odorous Water And Its’ Device R&D

As China’s urbanization process speeds up and the city’s scale is expanding,the phenomenon of urban black-odorous water is relatively common,affecting the sensory experience of people’s daily life and receiving long-term attention.This test mainly investigated the purification performance of Membrane Bio-Reactor(MBR)process for black-odorous water,and studied the operating conditions such as Hydraulic Retention Time(HRT),sludge concentration and influent alkalinity.The impact of the pollution efficiency;Focus on performance of Sludge-based activated carbon(SAC)enhanced MBR treating urban black-odorous water during the short hydraulic retention time.The two processes were compared to investigate the removal of pollutants from black-odorous water.The characteristics of the sludge,to explore the advantages of the SAC-MBR process;The last is the development of the entire set of equipment.The results show that,within a certain range(8-4 h),the MBR process has good purification performance for black-odorous water,and the removal rates of COD and ammonia nitrogen are 92.1%and 93%,respectively.When HRT is shortened to less than 2 h,due to the rapid accumulation of dissolved organic matter,the pressure difference across the membrane will rapidly increase to more than 8-12 kPa.The purification performance of the black-odorous water by the MBR process is poor and unstable.When HRT=1 h,the removal rate of COD and ammonia nitrogen in the MBR process dropped to the lowest point,which was 52.9%and 65.0%,respectively.In a certain range(2.0-8.0 g/L),the sludge concentration had little effect on COD removal efficiency.The increase of sludge concentration can slightly improve the ammonia nitrogen purification efficiency of MBR process,but excessive sludge concentration(≥8.0g/L)will inhibit the activity of nitrifying bacteria and further affect the ammonia nitrogen removal rate.When the alkalinity of the influent water is insufficient to support the nitrification of high-concentration ammonia nitrogen,alkalinity becomes the controlling factor of the ammonia nitrogen removal rate.The MBR process has a clear effect on the improvement of dissolved oxygen and transparency in black-odorous water.In a small part,the effluent will have a slight odor.The experimental results of SAC enhanced MBR process on the removal efficiency of black-odorous water showed that the SAC-MBR process has excellent performance in the removal of black-odorous water,and the average removal rate of COD and ammonia nitrogen is higher than that of MBR process when HRT=1 h.Increased by 21.5%and 21.3%.The ability to retain odoriferous substances(methanethiol,dimethyl sulfide,dimethyl trisulfide,etc.)has also been correspondingly improved.Through the structural analysis of the SAC and the study of the sludge characteristics,it was found that the surface of the SAC is rich in aerobic acidic functional groups and basic functional groups,and it is easy to adsorb water,free bacteria and organic matter,and forms a plurality of dense structures with SAC particles as the core.Mud flocculant,sludge particle size slightly larger than the MBR process,is conducive to improve the membrane flux,adsorption of organic matter and inhibit membrane fouling.At the end of this test,with a processing volume of 100 t/d,the SAC-MBR process was used to develop and design a complete set of equipment for the removal of black-odorous water.