Effect Of Low Concentration Chlorine Water Backwash On Ultrafiltration Membrane Fouling And Its Effect On Membrane Aging

In this paper,part of the content of the Chinese style is completed in the Chinesestyle base of the southern suburbs of Dongying City.Four sets of ultrafiltration membrane pilot test equipment are used to analyze the influence of the injection of drugs on the operation of the membrane.It was found that sodium hypochlorite can effectively control the increase in the transmembrane pressure difference and extend the maintenance wash cycle.Regardless of whether or not sodium chloride is added,the control of membrane fouling cannot show significant differences in this pilot plant.By measuring UV254 and three-dimensional fluorescence,it can be seen that the protein removal efficiency of the aromatic structure is significantly greater with the immersed membrane pool,and the pore size(0.01 ?m)of the internal membrane is lower than that of the other four membrane columns(0.02 ?m).The removal rate of potassium manganate index and turbidity is relatively high.By regularly testing the total number of bacteria in the effluent of the ultrafiltration membrane and the total number of coliform bacteria,it can be seen that the ultrafiltration membrane can almost completely remove pathogenic microorganisms.Back to the school laboratory,the problems found in the pilot experiments were further explored and related.The contents of the fourth and fifth chapters were completed,and the control efficacy and removal efficiency of the irreversible pollution of ultrafiltration membranes against chlorinated backwash were explored.It was found that sodium hypochlorite has a good control and even removal effect on irreversible pollution caused by humic acid water distribution.For a single pollutant,sodium hypochlorite has a good control and removal of irreversible ultrafiltration membrane fouling caused by humic organics,but there is no particularly noticeable effect on the removal of protein and polysaccharide organics.Studies have shown that ultrafiltration membrane performance and membrane structure exposed to sodium hypochlorite solutions can be affected by aging.The hollow fiber membrane structure is destroyed,the integrity of the membrane is affected,and the life is greatly reduced,the replacement cycle of the membrane is shortened,and the operating cost is increased.At the same time,taking into account the destruction of the membrane structure will affect the microbiological removal effect of the ultrafiltration membrane,posing a threat to the biosafety of the ultrafiltration device.Therefore,this article took out a chapter to explore the effect of sodium hypochlorite on the aging of ultrafiltration membranes.The effect of sodium hypochlorite on membrane filtration performance,retention performance,and physicochemical properties was analyzed.The CT value theory was used to try to find the ultimate strength and break point of ultrafiltration membrane exposure in sodium hypochlorite environment.Finally,it was found that the decrease in the transmembrane pressure difference of membranes exposed to sodium hypochlorite solution was positively correlated with the CT value in the early-middle period.However,under the environment of high CT exposure,the pressure difference will eventually show an upward trend.It is presumed that the high-concentration or long-term immersion of sodium hypochlorite is a distortion of the surface of the hollow fiber membrane yarn.The chlorination enhanced backwash includes the following features: It facilitates automatic operation;improves the overall water-producing performance of the ultrafiltration membrane;controls the contamination of the ultrafiltration membrane and prolongs the washing cycle;the required sodium hypochlorite is easy to procure and has a low risk of use.Professionals operate;various advantages such as high concentration of chemical cleaning waste liquid are not easy to handle.Although sodium hypochlorite has an aging effect on the membrane,it can be controlled within a certain range by controlling its concentration and soaking time.Therefore,summing up the contents of the full text and the technical characteristics of three sets of pilot plant designed by Li Jianshi,it is recommended that these three sets of Chinese devices be promoted in the rural areas in combination with the chlorinated enhanced backwashing process.