| In this project, we has determined the optimal reflux ratio, examined the factors affecting the removal of pollutants; investigated different causes of membrane fouling cleaning method by means of using real sewage, selecting Japanese Kubota produced LF10-type membrane module, combining with Anoxic-MBR Process.The results show that the experimental start-up phase activated sludge from the beginning to develop a mature training lasted26days. On stable phase of experimental,200%is the best reflux ratio, when HRT is8h, water temperature is16～20℃, PH is about7.0, SRT is15d and MLSS is5000mg/L around; System has efficient and stable removal of pollutants, in most cases, organic matter and ammonia nitrogen removal efficiency reached90%or more and met the "urban sewage treatment plant discharge standard of pollutants"(GB18918-2002) Basic controls the maximum allowable emission concentration A-level standard in the standard, However, due to the lower temperature and water anoxic carbon and nitrogen ratio, the competition between species, removal of total nitrogen and phosphorus is poor, only about50%removal; the effect of removal of pollutants main factors are MLSS, DO, C/N, SRT, because their changes will have a affect on the removal rate of the water quality to different extents. When MLSS was approximate5000mg/L, COD, NH3-N, TN, TP effluent removal rate were91.25%,93.22%,53.96%,51.31%; When DO was2～3mg/L, COD, NH3-N concentration were30.82mg/L,3.32mg/L and removal rate were91.14%,93.01%; When DO was1～1.5mg/L, TN, TP removal rate were60.67%,51.11%; When SRT were15d,20d,5d, COD, NH3-N, TP removal rate were92.13%,93.49%,61.92%, C/N of4.5～8and TN removal rate showed a good linear relationship.Although2.5m3/h of aeration and the use of siphon principles for water did not bring significant membrane fouling, but through two membrane cleaning, pure aeration+water backwash+caustic+pickling is a effective method to solve Organic chlorinated polyethylene membrane blocking. |
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