Development of Sanitary Treatment Methods of Membrane Wash Wastewater from Drinking Water Purification Plant

膜洗涤废水微生物安全性评价：以细菌和噬菌体为微生物指标，考察了它们在膜过滤中的去除性能、膜洗涤废水中的浓度和膜内的截留量。细菌和大颗粒噬菌体几乎被微滤器分离出来，并被冲到洗涤废水中。膜洗涤废水的浓缩实验考察了3种浓缩方法，即电解混凝/沉淀法、颗粒过滤法和沉淀/膜滤法。沉淀/膜过滤可生产出与饮用水一样的优质滤水。电解混凝/沉淀法可以排出浓度最高的污泥。高浓度污泥w(…)用铁阳极比用铝阳极得多，用铝阳极得到的上清液质量比用铁阳极好。考虑洗涤过程的膜过滤技术：由外而内的中空纤维膜过滤过程中，污泥在膜纤维周围和膜纤维之间堆积。纤维间堵塞是在流量低于临界错流速度的情况下发生的。临界错流速度为0.7m/S，在此速度下的剪切强度估算为200pa。膜过滤中试装置：聚乙烯微滤膜过滤采用实际原水。过滤前采用氯化、臭氧或紫外线照射等灭菌方法，可有效降低膜压升高。膜和化学洗涤废水分离出的物质包括多糖、蛋白质、多肽、氨基和多环芳香族化合物。较少

Evaluation of safety aspects of microorganisms in membrane wash wastewater : Using bacteria and coli phage as index of microorganisms, their removal performance by membrane filtration, concentration in the membrane wash wastewater and entrapped amount insid the membrane were investigated. The bacteria and larger size phage were almost separated by micro-filter and they were flushed out to the washing wastewater. The phage, Q beta , which was smaller than the pore size of membrane, was partially removed by MF but the separated phage was not whole discharged to the wash water.Thickening of membrane washing wastewater : Three types of thickening method, that is electrolytic coagulation/settlement, granular filtration, and settling/membrane filtration were investigated. The settling/membrane filtration could produced as good quality filtered water as drinking water. The electrolytic coagulation/settlement process could discharge the highest concentrated sludge. Higher concentrated sludge w … More as obtained with the iron anode than the aluminum anode, and better supernatant quality was gotten with the aluminum anode than the iron anode. The granular filtration was inferior to the other methods in both the separated water quality and the sludge concentration.The membrane filtration technology considering washing process : It happens in outside-in mode hollow fiber membrane filtration that the sludge accumulates around and between the membrane fibers. The inter fiber clogging was caused under the condition of lower flow rate than critical cross flow speed. The critical cross flow speed was 0.7m/s and shear strength at the speed was estimated 200Pa.Membrane filtration with pilot scale plant : Actual raw water was applied for the polyethylene micro-filter membrane filtration. Sterilization such as chlorimation, ozonation or ultra-violet radiation before filtration were efficient to reduce trance membrance pressure rising. The substances separated by membrane and chemical washing wastewater contained polysaccharide, protein, peptide, and amino as well as polycyclic-ring aromatic compounds. Less