Experimental Study On Airlift Biological Contact Oxidation Process For Decentralized Sewage Treatment

Processing and renewable utilization of decentralized wastewater is an effective supplement for sewageconcentrated treatment and recycle. Although many environmental companies have developed variousforms of integrated small distributed sewage treatment equipment of low energy consumption and greenpower source type, the practical effect of these devices is still lack of systematic information. This paper,combining with the characteristics of sewage quality, studied on the integrated processing performance ofthe reactor apparatus, which deals with decentralized sewage based on the biological contact oxidationprocess, the gas stripping type flow design and a series of advanced and appropriate control technology.Under the condition of normal temperature16~28℃, this paper firstly determined optimum operatingconditions of the contact oxidation process to deal with a residential sewage in continuous aeration mode.Then identified optimum aeration stop exposure time of water treatment after changing continuous aerationmode to the intermittent aeration mode under the optimum operation conditions. Finally, compared thesewage treatment effects of two operation modes.In order to keep sewage treatment effects under the low temperature, without any increase in engineeringconstruction and process operation costs, it is necessary to study the running effect of gas stripping typecontact oxidation process in low temperature environment. So this paper experimentally studied on thespecific change processes of gas stripping type hangs the membrane contact oxidation reactor start-uppacking biofilms SS and bioactive VSS/SS value and determined the sewage COD, ammonia nitrogen, TN,TP processing effect under8~15℃low temperature, and compared them with normal temperature16~28℃.Experimental results showed that the best exposure time of intermittent gas lift type contact oxidationreactor model was3.5h and optimal aeration time was7h under the operating conditions of dissolvedoxygen (DO) concentration of4.5mg/L and drainage of1/2. Intermittent operation mode not only cansave a lot of energy consumption, and make the water quality of ammonia nitrogen, TN concentration islower than the corresponding concentrations of continuous aeration operation mode of4.22mg/L and14.53mg/L because of a certain extent of alternating anaerobic and aerobic environment, the averageconcentration of2.93mg/L respectively, and10.88mg/L. The effluent COD values were similar, is between25to39mg/L.Under the8~15℃low temperature condition, the gas stripping type contact oxidation reactor start-upsuccess requires18days, the average removal rate of COD, ammonia nitrogen, TN, TP reached83.1%,69.9%,44.5%,69.9%, have strong ability to adapt to low temperature environment, removal effects ofCOD and TP are least affected by temperature, water except the TP reached “the town sewage treatmentplant pollutant discharge standard”(GB-18918-2002) primary standards, is a kind of very good smallsewage treatment facilities and technology at low temperature.