The Characteristic Studies On Urban Sewage Treatment By Membrane Bioreactor Modification

Recently, with the comprehensive application of chemical fertilizers, pesticides and detergents, N/P pollution and water eutrophication become more and more serious. Therefore, biological denitrification and dephosphorization process will be greatly applied and developed. MBR, (membrane bioreactor) as a new technology of efficient wastewater treatment, has gradually attracted great attention from researchers all over the world. Compared to conventional biological water treatment technology, MBR has a advantage of good water quality to be directly reused, small floor space, easy automation, high concentrations of activated sludge and low waste activated sludge. After several decades of developments, MBR has been an attractive and competitive choice in municipal and industrial wastewater treatment and reuse. It is considered as the 'best practical technology".MBR has a rapid development at home and abroad but its nitrogen removal rate only reaches 50% to 70%.Meanwhile, the effect of phosphorus removal is also not very good. In many cases, it must rely on chemical treatment to meet Corresponding sewage discharge standards. This experiment investigates a new type of MBR technology to treat municipal wastewater. After a long running time, the experiment has investigated various indicators of sewage treatment effect. Thus, the reasonable operating parameters optimizations are chosen. It concretely inspects the water quality and the removal rate of COD, NH4+-N, TP, TN in the reactor supernatant in order to reach the urban sewage treatment plant emission standards (GB 18918-2002) on wastewater reuse on water quality requirements.The results show that in the course of the experiment, water temperature, pH, DO, SRT, reflux ratio, HRT, and normal equipment condition have a significant impact on the whole removal rate. By inspecting changes in SRT, it gets the right parameters. The modified MBR process has added a anaerobic pond before the traditional MBR process, which can solve the contradiction on the sludge age between denitrification and dephosphorization. Meanwhile, it can also make sure the removal rate of nitrogen and phosphorus reach the standard of reuse water quality. The effect of the proportion of membrane bioreactor in the filler and processing volume of anaerobic tank has been adequately studied. By analyzing the treatment effect through reflux ratio, it obtains the optimal values of control parameters on modified reactor MBR:SRT 18d, HRT 6h, reflux ratio 1.5, DO 1.5mg/L.Through the analysis along the way of experiments, we get the specific removal effect of each reaction zone, point out the shortcomings of the experiment, and conduct a economic profitability analysis on the modified MBR at the end. Therefore, the reactor will have a better opportunity to develop and it could achieve a better treatment results by changing the settings, There is no doubt that It will have great utilization values and feasibility in both economic and social benefits.