Experimental Study On Treatment Of High Salinity Oily Wastewater With Electroflocculation Membrane Reactor

With the vigorous development of the petrochemical industry,the disposal of oily wastewater has received increasing attention.At present,the disposal of oily sewage basically follows the old three sets of technological processes: oil separation-flotation beneficiation-biological disposal.This treatment method occupies a large area and must continuously cultivate the number of biological colonies.In the treatment of oily sewage with high salinity and intermittent effluent,the high salinity-alkaline environment has obvious inhibitory effect on bacterial growth,which greatly affects the quality of effluent,and the effluent cannot be reused.Therefore,it is necessary to find a more efficient,reliable,simple and economical decontamination process.In view of the characteristics of high salinity oily wastewater,different from the previous staged process,an integrated electroflocculation membrane reactor(ECMR)was used in this paper to treat it.The ultrafiltration membrane module(UF)was placed in the electric field of the bipolar plates of the electroflocculation module(EC).The effects of different pH value environments,different current densities and different electric field strengths of this device on the COD removal rate and oil removal rate of raw water,as well as the situation and mechanism of alleviating membrane fouling were studied;under the same conditions,the ECMR device was also compared with The influence of traditional process UF and EC-UF process on COD removal rate and oil removal rate of raw water,as well as the situation and mechanism of reducing membrane fouling.By studying the influencing factors of ECMR treatment of high-salt oily sewage,it is known that as the current density increases,the relative membrane flux recovery rate of ECMR also increases.At 100 A/m2,the relative membrane flux recovery rate reaches89.8 %;Under the same conditions,the pH value of the raw water also has an impact on the anti-fouling performance of the membrane.When the pH value is 4,the relative flux recovery rate reaches 92.1%;the membrane flux recovery rate also increases with the increase of the applied electric field strength.,the relative membrane flux recovery rate was 94.2% at 3 V/cm.Through the comparative study of ECMR with UF and EC-UF,under long-term operation conditions(105 min),the decontamination efficiency of ECMR is obviously higher than that of UF and EC-UF,and the relative membrane flux recovery rate is also higher than the other two.craft.Not only that,the use cost of ECMR is also lower than that of UF and EC-UF.The internal mechanism for the above results is that the electroflocculation module can be used as a pretreatment device for the ultrafiltration membrane module to enhance the overall decontamination efficiency.It becomes fluffy and hydrophilic,which significantly improves the anti-fouling performance of the ultrafiltration membrane module.The improved anti-pollution performance of the system means that the system has more efficient decontamination efficiency and longer service life.