| Dynamic Membrane Technology,as a new type of urban sewage advanced treatment technology,besides the advantages of traditional membrane bioreactor,and large membrane flux,easy to backwash,which make it become a potential technology to possibly overcome the deficiency of the traditional membrane technology.Membrane fouling is the main bottleneck of membrane technology to further promote,and is an important reason for the extensive application of membrane bioreactor.In this study,membrane pollution was controlled and decreased by the combination of the addition and micro-electric field.In order to provide more powerful data support for popularization and application of the future technology.The study object of the A / O-DMBR technology in this topic by using nylon membrane as the membrane material,to simulate the domestic sewage as the treatment object,by means of adding the particulates and micro-electric field to improve the properties of the sludge mixture and the system of microbial denitrification and phosphorus removal performance.The filter cycle,the removal efficiency of pollutants,the characteristics of sludge,the impact characteristics of pollution load,the cause and mechanism of membrane fouling and the control of membrane fouling were investigated.The experimental data showed that the EPS accumulation in the reactor without micro-electric field(was named as rector A)is larger than that in the micro-electric field(was named as rector B)reactor.The content of EPS increased from 18.5mg /gMLVSS to 38.27 mg / gMLVSS and 16.71 mg / g MLVSS to 35.48 mg / gMLVSS in the rector A and B,respectively.The content of protein in reactor A was higher than that in reactor B,and the rate of membrane flux reduction in reactor B was lower than that in reactor A,and the cleaning frequency of reactor A is greater than reactor B.Above showed that micro-electric field was conducive to slowing membrane pollution.The results showed that the all indexes of membrane fouling in reactor B with PAM(was named as rector B)were lower than that with PAC(was named as rector A)in the reactor and PAM was superior to PAC in reducing EPS concentration and membrane resistance.The contribution of Rc and Rp to R increased with the extension of running time.The contribution of Rc to membrane resistance is much greater than that of Rp.The results showed that Rc was the main factor affecting themembrane fouling and the membrane resistance of reactor A was greater than that of reactor B.After adding PAM,the contribution of Rc to membrane resistance was significantly lower than that of reactor added PAC.PAM was superior to PAC in slowing membrane resistance and membrane fouling.The reactor with PAM synergetic micro-electric field had improvement in the sludge characteristics than the PAM reactor,and the indexes of membrane pollution caused by PAM synergetic micro-electric field were all lower than that of adding PAM.The results showed that the combination of addition and the micro-electric field reduced the EPS content in the mixture and the resistance of the sludge,thus slowed the growth of membrane resistance and reduced the membrane fouling.The model of filter cake blocking in micro-electric field synergic addition assumed that the filter cake layer forming on the surface of the membrane was filterable,which reduced the rate of membrane flux decline and delayed the membrane fouling.The plugging model of addition was some pollutants of similar in size to the pores of the membrane that blocked the pores of the membrane at the first time.At the same time,some of the pollutants adhered to the membrane pores,and resulted in a complete blockage of the membrane pores and more serious membrane fouling.From the electron microscope scanning of the photos could be intuitive to see the dynamic membrane formation of micro-electric field was more loose and pores were more,which ensured the membrane flux. |
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