Research On Application Of The Ultrafiltration Technology In Polluted River Water Treatment

Because most of colloids, macromolecular compounds and bacteria and other impurities were removed in ultrafiltration system, with low-energy consumption, no-phase change and easy operation. So ultrafiltration was widely used in the field of water treatment. In the study, application of the ultrafiltration treatment technology for polluted river water was researched.Coupled biological-UF test showed that system can remove turbidity, color, ammonia nitrogen, iron, manganese and organic matter, effectively, even in lower temperature in jiaxing river water with high ammonia and high organic matter, the water quality can meet the requirements of China national standards for drinking water quality (GB5749-2006). At the same time the optimal condition and economic operating condition were found in the coupled biological-UF system under different experimental conditions through orthogonal experimental.Experimental result and optimal operation were researched in ultrafiltration system that was used as the core of the combination of technology (raw water-biological pretreatment-coagulation-ozone contact oxidation-biological activated carbon-ultrafiltration). In the experiment the four problems were researched.1) The experiment results of submerged and inside-out membrane system and secondary pollution in submerged ultrafiltration system. The result showed that ultrafiltration membrane was used as the core of the combination of technology could be better to meet the requirements Standards for Drinking Water Quality (GB5749-2006). The submerged ultrafiltration system was vulnerable to outside interference, caused the secondary pollution. The study analyzed the reasons mainly from the bacteria in air, the membrane structure, biological stability as well as production tank. And some solutions were studied to control secondary pollution in the treatment system.2) The correlation of particle number in the influent and effluent of the submerged and inside-out membrane system. The results showed that the particle number of same size distribution was consistent in the influent and effluent, moreover, the submerged and inside-out membrane system showed the same changes. The study analyzed the possible reasons from the membrane pore size distribution and air particulates.3) The method of testing the high concentration of particles in the submerged and inside-out membrane system. When the particle concentration of influent was25000/ml, the study used different dilution ratio, the accuracy of the instrument test results were reviewed and verified. The experimental results showed that, the size distribution of particle counts in keeping with the dilution method. Only in the particle size distribution of2-3μm, which could produce more error. Some reasons were analyzed in this study.4) The optimal operation condition in the submerged ultrafiltration system under different operating conditions, the results showed, operation cycle, aeration time, mode of operation and backwashing had a great impact on membrane fouling, so the reasonable operation time and aeration backwashing are very important to stable operation of UF system. The mode of operation, energy consumption, water production efficiency and avoiding the secondary pollution were analyzed, we concluded that the operation mode of running5minutes, stop1minutes, aeration from start to end was a relatively ideal method.