Membrane Fouling Mechanism And Control In Treatment Of Secondary Effluent From Sewage Plant By Ultrafiltration

Ultrafiltration is a suitable treatment method for deep sewage treatment.However,the organic matter(EfOM)in secondary effluent will affect the ultrafiltration performance to a large extent.Due to accumulation of pollutants in the membrane surface or the membrane pores,and most of the organic pollutants in wastewater with dissolved extracellular polymer substances(EPS)or soluble micr obial products(SMPs)cause irreversible deposition,is often characterized as membrane and membrane proteins and polysaccharides is given priority to,make the membrane fouling problem become more prominent.Test to investigate the effect of operation pressure,can observe the ultrafiltration operation pressure increases will affect the ultrafiltration membrane pollution and resistance distribution and flux decrease trend with the increase of operation pressure,the greater the pressure,the more obvious the membrane pollution,membrane pore blockage and cake layer accumulation although lowered the water capacity,but to a certain extent,to strengthen the ultrafiltration membrane's ability to intercept pollutants,closely thick parts of the filter cake layer adsorption EfOM can intercept or organic matter,when the membrane fouling increased to a certain extent after must use hydraulic or chemical cleaning way make flux as far as possible back to the original state,Hydraulic backwashing can remove the resistance of the EfOM filter cake layer,but it only increases the irreversible resistance of the membrane when organic matter is blocked or adsorbed in the membrane hole.EfOM has played a leading role in membrane fouling.As part of the separation of their individual contribution to the ultrafiltration membrane irreversible adhesion is more significant,suggesting that ultrafiltration technology in advanced treatment of wastewater,the most effective control and reduce the membrane fouling of strategy should be to eliminate the effect of EfOM biopolymers.Because of the influence of the biological polymer mainly by biological activity,its quality and quantity must be affected by the handler,detailed studies are needed to optimize biological process,reduce the production of biopolymers,thus can be considered before ultrafiltration process take appropriate pretreatment method,reduce the EfOM biopolymers,alleviate the membrane fouling,increase ultrafiltration membrane filtration cycle.This test examines the preoxidation(ozone)and coagulation(aluminum sulfate and ferric chloride)combination of ultrafiltration membrane fouling,the influence of the flux change,membrane resistance distribution and reversibility analysis concluded that: ozone and coagulation pretreatment were significantly reduces the pollution of ultra-filtration membrane,use after pretreatment,water flux,membrane fouling rate has fallen dramatically,as the ozone and the increased amount of coagulant dosing,accordingly reduce membrane resistance;In addition,the application of pretreatment has significantly improved the water quality of ultrafiltration effluent,the water quality purification effect is obvious,and the pollutant removal rate is greatly increased.The removal effect of PPCPs small molecular organic matter by deep sewage treatment was investigated.Chemical flocculation is one of the most commonly used methods,because coagulation has a good removal effect on high molecular organic matter such as humus in raw water.As a pretreatment process of coagulation,ozone oxidation,activated carbon filtration and membrane filtration has proved to be most effective and feasible technology,to reduce the amount of PPCPs in water,but coagulation to remove only a small part of the drug;Pre ozone advanced oxidation technologies,such as more and more be used in pretreatment of conventional water treatment process,because the ozone can attach great importance to the role of some conventional processes such as coagulation,increasing the number of remove various pollutants from water to water,some refractory male in raw water adsorption removal of small molecule organic matter such as PPCPs,ozone can effectively make the chemical bond rupture and explain in detail,but the other organic pol lutants in the EfOM with competition mechanism,degradation reaction order,finally investigates the ultrafiltration membrane filter cake layer of PPCPs the influence of organic matter,proves that the filter cake layer intercept or adsorption effect.