Experimental Study On The Denitrifying Phosphorus And Nitrogen Removal Of Domestic Sewage In Continuous-flow Intergrated Biological Reactor

Among all various ways to treat domestic sewage, the theory of biologicaldenitrification phosphorus and nitrogen removal is an effective one to improve thenitrogen and phosphorus removal efficiency of the new bioreactor and biologicaltreatment process. With the advantage of low energy consumption, integrated continuousflow, effluent quality, the CIBR(Continuous-flow Integrated Biological Reactor) process isa nutrient removal process, which is easy to operate. The purpose of the subject is topromote the development of the research in the domestic sewage treatment of CIBRprocess, it studied the feasibility of denitrifying phosphorus and nitrogen removal in CIBRprocess which used artifiical sewage as treatment object. The variation of DO, ORP, pHand the impact of different factors on denitrication and phosphorus removal have beenstudied in the topic.The study of denitrification and phosphorus removal in CIBR has shown that:(1) Inthe anoxic stage, denitrifying phosphorus and nitogen removal could be achieved duringthe CIBR process, meanwhile the effluent of CIBR process could reach the first B-gradedischarge standard specified in Discharge Standard of Pollutants for MunicipalWastewater Treatment Plant(GB18918-2002). On the process of the reator operation,theremoval rate of COD, TN, NH4+-N, TP would reach85.62%,74.58%,79.82%,75.94%individually.(2) During the denitrifying phosphorus removal process, pH, ORP and DOshowed indication of the reactor on the different stages (anaerobic/anoxic/aerobic). Thechange of pH, ORP, DO and temperature can be used to adjust the operational status.The study of the factors affecting denitrification and phosphorus removal has shownthat: Nitrate concentrations, different electron acceptors and sludge concentration were thefactors which can influence the denitrication and phosphorus.(1) The denitrifyingphosphorus sludge can use nitrate instead of nitrite as an electron acceptor to absorbing phosphorus in denitrification stage. With nitrate concentration increasing, phosphorusabsorption capacity increased. The activated sludge in CIBR showed good phosphorusabsorption capacity when nitrate concentrations between20.57-37.55mg/L. It wouldinhibit denitrifying phosphorus when nitrate concentrations blow11.18mg/L; andphosphorus uptake did not significantly increase when nitrate concentrations higher than37.55mg/L.(2) Under aerobic and anoxic conditions, activated sludge in CIBR showedgood phosphorus absorption capacity. However anoxic phosphorus uptake rate was lowerthan the aerobic phosphorus uptake rate. The effective of phosphorus absorption which O2as an electron acceptor was better than nitrate as electron acceptor.(3) Under anoxicconditions and nitrate sufficiency, when the sludge concentration was higher, the amountof phosphorus absorption was greater and the phosphorus absorption rate was lower.