Study On The Low Carbon Domestic Sewage Treating By The Anaerobic/Aerobic Biological Beds

As low carbon source and disproportionality of C, N, P of municipal wastewater, common activated sludge process and BAF can not remove N, P with high effectively. How to get a high removal rate has been interested by many researchers. Zeolite and ceramsite as the packing bed materials in the test, anaerobic/aerobic process as reference, to investigate and compare the relatively removal efficiency of two packing materials in the process, so as to select the better packing material.The results showed that, anaerobic/aerobic- zeolite process has a better removal efficiency which was 86.18%,83.76% and 70.96% for COD_Cr,NH₃-N and TP, repectively, the final effluent concentration was 19.23 mg/L ,2.66 mg/L and 0.36 mg/L for COD_Cr,NH₃-N and TP, respectively which meet the standard of sewage discharge standard of sewage treatment plant. The removal efficiency of anaerobic/aerobic- zeolite process was better than anaerobic/aerobic-ceramsite process and activated sludge. This process has better removal efficiency in COD_Cr,,NH₃-N and TP, recucing the contaminant loading of aerobic biological bed, doing good to realize the high removal efficiency of anaerobic/aerobic- zeolite process, meanwhile, it saved motive power which reducing the cost.The results of COD_Cr/NH₃-N on the effect of P removal efficiency showed that: when the inflow COD_Cr/NH₃-N was 5-10, the removal efficiency of NH₃-N and TP for anaerobic/aerobic packing biological bed process was better than activated sludge. The results of NO3--N on the effect of P removal efficiency showed that low concentration of NO3—N(0.5mg/L¹.2mg/L)had quite little effect on NH₃-N and TP removal efficiency on the anaerobic condition. Yet had better removal efficiency on the aerobic condition when the NO3--N concentration change (0.5mg/L³.0mg/L).The biomembrane grew fast and stable on the surface of zeolite bed which showed that the biomembrane was stable, not easy aging, packing layer not easy harden, suit for long-time running. The biomembrane grew on the surface of ceramsite was not so stable and easy to fall off and harden would appear if long-time running, hard to have stable operation.Experimental results showed that the removal efficiency of COD_Cr,NH₃-N, TP is not obvious when the anaerobic/aerobic biological bed process naturally. The aeration can just improve the DO concentration of effluent, yet can not improve the removal efficiency. As for the anaerobic/aerobic activated sludge process, the removal efficiency of COD_Cr is obvious and even below 50mg/L, sometimes, yet the removal of NH₃-N and TP were not obvious. The adjusting methods as below would help to improve the removal efficiency: adjusting the inflow automatic control to intermittent control, adjusting the oxygenator to automatic control, inflow intermittently and intermittent oxygenate in aeration pool, launch the sludger to get inverse sludge timely everyday, adjusting the water inlet on the bottom of aeration pool.