Removal Of Buprofen And Bisphenol A From Drinking Water Sources And Studies Of Membrane Organic Pollution By Nanofiltration Membrane

ETCs in the environment is a potential threat to human in the aspects of survivaland stability of the ecosystem. They will eventually enter the water as a cyclic effect,and produce serious interference effect on the aquatic ecosystems.With the development of membrane technology, a number of researches abroadshowed that the membrane separation technology was effective in removal of ETCs.The rejection characteristics of Nanofiltration membrane is between reverse osmosismembranes and ultrafiltration membranes, and nanofiltration membrane has betterseparation efficiency, lower operating pressure, less costs, and many other advantagesthan other membranes. This paper has studied the process of which nanofiltrationmembrane removed buprofen and bisphenol A that are two typical of ETCs microenvironmental pollutants. And has analyzed some factors to affect the membrane separationperformance, including the difference between the two pollutants in the nanofiltrationprocess, pH, absence or presence of NOM and pre-contact time, and so on.It concluded from above experiments that:(1)In the filtration process,the average permeate flux of IBUaq with higher Kowis lower than BPAaq; the rejection performance of IBU solution by nanofiltrationmembrane played higher than BPA solution; cumulative adsorption amount on unitmembrane area of IBU has7.54mg·m-2·h-1more than BPA.(2) In the filtration process, two kinds of ETCs in aqueous solution flux increaseswith pH value.In the conditions of neutral and acidity, IBUaq has higher average fluxthan BPAaq. The ionization of IBUaq is always larger than the BPAaq for the wholeprocess. The mutually exclusive role between IBU and membrane surface is strongenough to keep the IBU being a high retention performance.(3)After adding the NOM, membrane flux are significantly lower in twosolutions, and the trend is basically the same. There has been a interaction fromcertain substances in NOM to membrane surface with charge, and acted better thanthe two ETCs. NOM adsorption to the formation of fouling layer on the membranesurface leaded the two ETCs pollutants in the nanofiltration process permeate fluxdecline, and the value of the retention rate increases, the membrane face adsorption ofthe IBU and BPA decreased. (4)For pre-contact time increasing, the starting flux of IBUaq during thenanofiltration process was comparatively large to BPAaq. The cumulative adsorptionamount of IBU on the membrane has little to do with pre-contact time.But due to thestrong adsorbing power of BPA, the pre-contact time have a greater impact length onfollow-up of nanofiltration process of the BPAaq.(5)In the nanofiltration process, the intrinsic membrane resistance Rm has stablyoccupy most of the membrane resistance; after two ETCs pollutants added NOM,from start to finish the gel layer resistance Rg has little change; the absence of NOMincreases the membrane surface pollution,particularly it has a greater impact on BPAsolution nanofiltration process.