Ultrafiltration System In Waterworksin Upgrading Pilot Study And Application

With the deterioration of water environmental pollution and the stringent drinking water standards, conventional water treatment technology appeared its lack in efficiency. Application of membrane technology to drinking offers many small footprint.This test takes Tai lake water as raw water, going on advantages such as low turbidity of treated water and water treatment o year. In this test two membranes which are out-inside membrane and in-outside were compared. The condition in which the two membranes can run stably was discussed. Furthermore, the water quality of effluent from the traditional treatment process and that from Coagulation-Ultrafiltration process were compared.Firstly, the optimal pretreatment conditions of the two membranes were investigated firstly, and found that coagulation could mitigate the increase trend of trans-membrane pressure, Because coagulation could change the electric charge of granules and weaken the strength between granules and the strength between granules and membrane. In this way, pollutant layer could be washed away easily with reverse-flushing (RF).Secondly, In the experiment aimed at confirming the operation parameters, results showed that the optimal run condition of in-outside membrane is that the flux was fixed at 4t/h and the duration at 30min during filtrating, and the duration of both upflow-RF and downflow-RF was fixed at 30s, and the flux of RF at 7t/h. Out-inside membrane has the same flux and the duration during filtrating, but the flux and the duration of upflow-RF were 1.2t/h and 40s, downflow-RF 8t/h and 40s. Out-inside membrane exceled in-outside membrane in the reclaim rate, but out-inside membrane's resistibility is weak.The water quality of filtrate from Coagulation-Ultrafrltration process is good. Membrane filtration could remove organic compounds and ammonia nitrogen with low efficiencies, whereas much of the turbidity and biomass could be eliminated with flux having little effect on it. After membrane filtration Fe existing in the water would be at a low level, nevertheless, affected by the pretreatment Mn could not be removed efficiently, and the alkalinity and residual chlorine could be almost the same. The turbidity of filtrate from in-outside membrane is low than 0.2NTU, The removal rate of CODMn is about 35%.The water quality of the filtrate from Out-inside membrane is worse than that from in-outside membrane.Therefore, from the overall removal effect, UF for advanced treating has. more advantages. The method is simple, efficient, quick and feasible.