Study On Pollution Control Mechanism And Water Treatment Efficiency Of Submerged Ultrafiltration Membrane

In recent years,with the continuous improvement of residents’ requirements for water quality and the increasing emphasis on drinking water safety,water companies across the country have begun to carry out in succession the advanced treatment process transformation of waterworks,and how to meet the requirements of the new national standard while reducing the operation cost has become the key to the operation of waterworks.Ultrafiltration(UF),as an advanced treatment process,can further remove bacteria,viruses,colloid magazines and macromolecular organics from water without generating other substances.Moreover,submerged ultrafiltration membrane has extensive application potential in drinking water treatment due to its large filtration area and convenient installation.However,the problems of high maintenance cost of ultrafiltration membrane filament and serious membrane pollution are the main limiting factors that ultrafiltration membrane cannot be widely applied at present.This paper mainly studies the influence of membrane characteristics and pretreatment on the filtration performance of submerged ultrafiltration membrane.By comparing the water treatment efficiency of waterworks with conventional treatment process,ultrafiltration and a small-scale ultrafiltration membrane treatment device,the paper puts forward the optimization scheme of membrane operation.And the main research contents and conclusions are as follows:Water quality analysis was carried out on the removal rate of each process unit in No.3 Water Plant using ultrafiltration membrane treatment technology.Among them,the effluent quality of ultrafiltration membrane unit is stable and is less affected by changes in raw water quality,with an average removal rate of 99.72%for turbidity.Other effluent quality indexes such as oxygen consumption,ammonia nitrogen,microorganisms and trihalides all fully meet drinking water standards.However,sedimentation tank and biological activated carbon filter are easily affected by temperature.The ammonia nitrogen effluent of carbon filter in winter is about 0.02 mg/L higher than that in summer,and the sedimentation tank is about 0.03 mg/L higher.Analyze the effluent of the second waterworks without ultrafiltration membrane and the third waterworks with ultrafiltration membrane in the past three years,we found that turbidity removal effect is the most obvious.The third waterworks has a lower turbidity of the factory water than the second waterworks by 47.37%;the removal of oxygen consumption,ammonia nitrogen and the total number of colonies is limited;the removal effect of iron and manganese is equivalent.Study the effluent quality of ultrafiltration membrane modules operating at zero pollution flux.Comparing the effects of different combined processes,it was found that pretreatment processes such as activated carbon filtration can effectively reduce the rate of membrane pollution,effectively prolong the service life of ultrafiltration membrane,and provide new ideas for the renovation of No.2 Water Plant.At the same time,it operates for a period of time under zero pollution flux,reduces the cleaning frequency,and extends the chemical cleaning cycle to 10 days.It is found that the water plant not only meets the basic water quantity,but also has little difference in the water purification efficiency of the effluent.And it can reduce the operation cost of about 1627,400 yuan per year.