Study On Development And Effectiveness Of Integration Equipment For Moving Bed Biofilm Reactor

With the rapid progress of Urbanization in China,the discharge of domestic sewage and industrial wastewater in small towns were also increasing year by year.In addition,the pipe network was not well-constructed,and there was limited sewage treatment facility or the operation was improper,which made the severe environmental pollution and the extremely urgent sewage treatment situations.Moving Bed Biofilm Reactor（MBBR）had the following advantages:low energy consumption,strong impact load resistance and strong adaptability to temperature,which was suitable for most small towns in southern China.For this reason,according to the characteristics of sewage water quantity and quality,combined with relevant specifications and engineering experience,this paper firstly developed a set of MBBR integrated equipment,and studied the equipment starting and the biofilm culturing.And then,the effects of the equipment on sewage treatment and the optimum influencing parameters were both investigated under the design condition.At last,the technical and economic situations of this integrated equipment were analyzed to provide data references and technical supports for the engineering popularization and its application.The main contents and conclusions are as follows:（1）The MBBR integrated equipment was developed according to relevant specifications and engineering experience.The integrated equipment adopted the vertical combination of anaerobic pool,anoxic pool and the transverse combination of biochemical tank,sedimentation tank and equipment area.On the one hand,it could ensure the reasonable distribution of dissolved oxygen along the road;on the other hand,it could avoid the high energy consumption of the integrated device.As a whole,the process was compact and the arrangement was reasonable.The equipment starting and the biofilm culturing were studied,and the results showed that,after 16-day operation,the removal rates of COD_cr,NH₄⁺-N were stable,metazoans such as Vorticellidae and Nematode could be observed,and the biofilm was successful cultured;（2）The effects of MBBR integrated equipment on sewage treatment under design condition were also studied.The results showed that,under the design conditions（inlet flow rate of 10 m³/d,hydraulic retention time of 8 h,gas/water ratio of 3:1,and nitrification reflux ratio of 150%）,the average removal rates of COD_cr,NH₄⁺-N,TN and TP were 75.40%,82.55%,44.64%and 81.08%,respectively,which could meet the requirements of Level I Standard B of Pollutants Discharge Standards of Urban Sewage Treatment Plants.Through test of hydraulic retention time,gas-water ratio,nitrification reflux ratio and other factors,conclusions could be arrived that the best operating parameters of this integrated equipment were hydraulic retention time of 8 h,gas/water ratio of 5:1 and nitrification reflux ratio of 200%;（3）The MBBR integrated equipment had a daily treatment capacity of 10 m³,covering an area of 4.4 m²,the overall cost of 60,000￥,the specific water treatment costs of 0.418￥/ton and the specific operating costs of 1.404￥/ton.If this equipment could be mass produced,the daily treatment capacity of the MBBR integrated equipment was 50 m³,covering an area of 21.5 m²,the overall cost of90,900￥,the specific water treatment costs of 0.37￥/ton and the specific operating cost of 1.12￥/ton.