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Study on Phenolic Alcohols Substance in the Area of the Surface Water of Weihe River and UF/NF Separation Efficiency

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Tutor: WangLei
School: Xi'an University of Architecture and Technology
Course: Environmental Engineering
Keywords: phenols,Steroids,ultrafiltration,nanofiltration,membrane flux,interceptionrate
CLC: X832
Type: Master's thesis
Year:  2012
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Abstract:
Phenols and steroids types environmental hormone is a type of toxic chemicalsubstances in the entironment, it can be absorbed by creatures through food chain ornormal contact, as a result, it would interfere with creatures¡¯ nervous¡¢endocrinology¡¢reproductive system, this kind of substance has a serious hazard to human or creatures¡¯health. In this article, we choose four typical phenols2,4-Dichlorophenol,pentachloropheno,4-nonylphenol,bisphenol and four steroids types environmentalhormones estrone,ethinyl estradiol,estradiol,estriol as the objects of my study.We usesolid phase extraction and gas chromatograph-mass spectrometer to determination,andrecearch deposit and assign rules of phenol-alcohols environmental hormones in themiddle of Weihe river,and through the combined with ultrafiltration-nanofiltration toreceach its separation efficiency,main conclusions as follows.(1)In the different time,we analyzed and detected phenol-alcohols environmentalhormones in the middle of Weihe river,the results show that pullution of phenol-alcoholssubstances is quite serious,consistency of2,4-Dichlorophenol is0.009¡«3.899¦Ìg/L,pentachloropheno is0.003¡«55.481¦Ìg/L,4-nonylphenol is0.004¡«2.227¦Ìg/L,bisphenol is0.055¡«128.122¦Ìg/L, in alcoholic substances,consistency of estrone0.027¡«6.679¦Ìg/L, ethinyl estradiol is0.010¡«11.409¦Ìg/L, estradiol is0.015¡«18.546¦Ìg/L,estriol is0.034¡«18.674¦Ìg/L. In these results, the consistency of PCP,BPA and E2isbeyond the national environmental quality standards for surface water, and theconsistency of rest hormone substances are also beyond the investigation results ofsurface water concentrations abroad.As the seasons change,changes in water content of phenolic alcohols are large,the relationship is drought period>normal level period>highflow period.(2)In ultrafiltration experiment,compare with the influence of ultrafiltrationmembranes which molecular cut off is50k,100kDa intercept phenol-alcoholshormones.The results show that,the aperture of100K ultrafiltration membrane isrelatively large,although water flux is large,rejection coefficient of membrane is too low.The rejection coefficient of50K ultrafiltration membrane is over90%.As a result, we use50K ultrafiltration membrane in our experiment.(3)In the ultrafiltration experiment of the coexistence of humic acid and Phenolalcohol substances,turbidity has a big impact to rejection coefficient,with the increasingof turbidity,the interception rate of phenol-alcohols estrogen is from descend to ascend.When turbidity is5NTU,it gets the best separation effect and highest rejectioncoefficient.Because of humic acid form micelle or polymer as micellar structure existingin dissociation solution,perform the property of colloid particle,it is easy to absorb in thesurface and opening of membrane,reduced membrane aperture,improve interceptingrate.and after add solution of kaolin,phenol-alcohols estrogen is easy to be absorbed onhumic acid and kaoline macromolecules,increased solute equivalent diameter,improveintercepting rate.At the same time,adding solution of kaolin increasing membranepulltion,membrane aperture become smaller,increasing interception rate.(4)In the nanofiltration experiment of appending phenol-alcohols estrogen in purewater,separation characteristic of nanofiltration membrane affecting to phenol alcoholsubstances:membrane flux increasing with the operating pressure,and with theincreasing of operating pressure, the trend of interception rate is ascend todescend.When the operation pressure reach0.4MPa,the interception rate ismaximizing.With the increasing of PH value,membrane flux and interception rate alsoincreasing.Negative charge in the membrane suface and solution is raising with PH value,and the negative charge with phenol-alcohols hormones strengthen the electrostaticrepulsive-force between solute particles and membrane surface,lead to the increasing ofinterception rate.Membrane flux and interception rate is decreasing with the increasing ofionic strength,to cause the compression of double electrode layer on surface,decreasing size the membrane opening,flux down,meanwhile weakening electrostaticrepulsive-force between solute particles and membrane surface,decreased interceptionrate.
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