Research On Processing Wastewater In Low Temperature By Membrane Bioreactor

Natural water body of north region can receive few pollutants at low temperature in winter. The outflow of traditional wastewater treatment technology has bad quality because of the low temperature. So the load of water body gets heavier. It's very important to improve the point pollution treating efficiency of wastewater treatment plants for river restoration and water quality improvement. Membrane bioreactor has many advantages, such as the high sludge quantity, the high processing efficiency, interception efficient membrane and few excess sludge output. It can improve the effect of sewage treatment in low temperature. then it has been paid more attention and application by more and more people. This article will focus on the treatment of sewage under low temperature performance of MBR process analysis and discussion, and optimization operational factor.First, HRT and DO was investigated on the low temperature effect MBR Process in a small pilot test.The removal effect of COD and NH3-N was enhancement when reactor HRT increases from 4h to 10h. In the HRT was 6h and more, the removal effect of COD had more than 88%, effluent COD were 50mg/L the following. In the HRT was 8h and more, the removal of NH3-N to achieve the best, effluent NH3-N were 5mg/L the following. The removal effect of TN was enhancement when reactor HRT increased from 4h to 8h,but decreased from 8h to 10h.The best removal effect is 62% when HRT was 8h.This is because HRT is long time, changes in organic loading affected the effect of SND, then effects caused by accumulation of NO3-N in the treatment effect.The removal effect of COD was above 90%, and do not change much when the concentration of DO was from 1mg / L to 5mg / L, the removal effects of NH3-N is increasing, and the removal effect of NH3-N is 82.5% when DO was 1 mg / L. As the higher DO inhibited denitrification process NO3-N massive accumulations. The removal efficiency of TN was decreased with the increase of DO, the best removal effect is 68% when DO was 1 mg / L.Design the pilot test based on the small scale of the operation parameters, commissioning of HRT for the test system in 8h, DO in the 1mg / l or so, the system has the good elimination effect.In the early running,COD removal rate of over 90%, NH3-N removal efficiency of 85%,also, as outside the circle of sludge increased phosphorus removal ,removal rate of over 75%. System instability as the running time shorter,so the denitrifying bacteria accumulation is insufficient, the removal efficiency of TN is not very good,it must further raise.