Study On The Treatment Of Municipal Wastewater By High-efficient Anaerobic Technology

Recently anaerobic biological technology was largely applied in treatmentof high-concentration organic wastewater because its benefits of stableprocess,saving energy,and running simply. But conventional anaerobic reactor hadthe faults of low mass transfer rate ,low microbe activity to treat low-concentrationwastewater,and no fashioned anaerobic reactors were used to treat municipalwastewater.Therefore the key problem was to research high-efficient anaerobicreactors to treat municipal wastewater.A high efficient anaerobic process of spiral flow Anaerobic Baffled Reactiontreating wastewater is demonstrated in this paper. Through designing of scientificreactor structure, For purpose of enhancing mass transfer in the improved anaerobicreactor through increasing reflux equipment. Through reflux better hydraulicconditions were achieved in the system and organic acid was prevented fromaccumulation. and the efficacy of wastewater treatment was improved.Multi-stages and two-phase anaerobic process was proposed for municipalwastewater treatment in this paper. Through operating pH of different stages, twophases separation was realized, biochemical reaction conditions were betteracquired ,and hi-efficient organic removal rate was achieved.Test results showed that:the anaerobic baffled reactor was run under singlephase situation,when hydraulic residence time was 4h,the removal rate of SCODreached 35.5%;when effluents was reflowed to the front of reactor,optimal refulxratio was 100% ,the removal rate of SCOD reached 37.5%.traditional two phaseanaerobic running format was studied , utilizing the methods of dynamics controlto realize phases separation , when hydraulic residence time was 4h ,optimal refulxratio was 100%, the removal rate of COD reached 42.6%;utilizing physiochemicalmethod to realize phases separation , when hydraulic residence time was 4h , theremoval rate of COD reached 44.6%, when hydraulic residence time was 10h , the removalrate of COD reached 75%.Under the condition of Multi-stages and Two phases anaerobicprocess, when hydraulic residence time was 10h ,the removal rate of COD reached 93%.It was efficient to use this system to treat municipal wastewater ,whenhydraulic residence time was 8h above, the removal rate of COD was beyond 90%,andCOD value could reach discharge criteria.Because of low removal rate of TN,TN valuecould not reach discharge criteria,and aerobic treatment was necessary.But thisprocess could make scale of aerobic facility reduced about 70% ,under theprecondition of assuring effluent quality ,investment of engineer could reduced30%-40%,saving power consumption about 50%,running expense decreased 40%,and hadhighly economic efficiency.The innovation of this paper was that new type anaerobic reactor was initiallyused to treat municipal wastewater,and proposed multi-stage and two-phase anaerobicprocess, and largely improved the efficiency for anaerobic reactor to disposemunicipal wastewater.