| Dynamic membrane bioreactor（DMBR）is a new type of water treatment technology which is developed based on membrane bioreactor（MBR）process and combines dynamic membrane filtration technology with traditional activated sludge process.Once published,it has been widely concerned by researchers at home and abroad.However,the problems of dynamic membrane pollution,water quality fluctuation and low phosphorus removal rate limit its further popularization and application.Recent studies show that the electroflocculation process can enhance the removal of pollutants from activated sludge system,and the electroflocculation process can alleviate the pollution of MBR membrane.Inspired by this,this study coupled the electric flocculation process with DMBR technology,investigated the changes in the operation efficiency of the integrated reactor,and analyzed the change mechanism of membrane pollution in the coupled reactor combined with the characteristics of mixed sludge.To explore the treatment efficiency of coupling technology on refractory industrial wastewater,in order to expand the application field of new technology.The main research contents and results include:（1）The influence of the coupling reactor on the removal rate of conventional pollutants was investigated.The results showed that the electric flocculation DMBR reactor had a significant promoting effect on the removal of pollutants,among which the removal rate of total phosphorus（TP）was increased significantly,which was more than 98%.The removal rate of chemical oxygen demand（COD）and ammonium nitrogen（NH4+-N）also increased to a certain extent.（2）By detecting the contents of extracellular polymeric substances（EPS）in the mixed liquid in the coupling reactor,it was found that the electroflocculation process can reduce the contents of proteins and polysaccharides in the solution,which plays a positive role in alleviating membrane contamination.The comparison of mixed liquid characteristics during operation showed that conventional indexes such as sludge concentration,settleability and particle size all fluctuated within the normal range without significant changes.Based on the analysis of Zeta potential and contact Angle,the filterability of electroflocculated DMBR sludge was greatly improved.（3）The effect of electroflocculation on the membrane fouling of the reactor was investigated.The results showed that when the control reactor ran for 5 cycles,the electroflocculation DMBR only ran for 3 cycles,indicating that the introduction of electroflocculation greatly reduced the membrane fouling rate and extended the operation life of the reactor.Compared with the control membrane bioreactor,the energy barrier of the total interaction energy of the experimental reactor was higher and the membrane fouling tendency was lower.From the perspective of information transmission between microorganisms,the introduction of electric flocculation inhibits the information transmission process between microorganisms,affects the generation of EPS,and thus plays a role in alleviating membrane pollution.（4）To explore the application feasibility of electroflocculation DMBR coupling reactor in the field of refractory industrial wastewater treatment,construct three groups of pretreatment systems,and compare their degradation performance.The results show that the iron carbon microelectrolysis pretreatment process has higher economic efficiency and treatment effect,and the COD of wastewater treated by this process can be reduced to about 45%.On this basis,a desulphurization wastewater treatment system is constructed,through which the COD of produced water can be reduced to less than 20 mg/L to meet GB8978-1996 "Comprehensive Sewage Discharge Standard" national level discharge standards. |
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