摘要
本文介绍了超滤原理、应用概况、超滤存在的问题、防止超滤膜污染途径以及有机-无机膜的研究进展等。大量文献报道在有机膜中添加无机填料可以提高膜的耐污染性能、渗透性以及增强膜的机械强度和延长膜的使用寿命。而目前在有机-无机超滤膜的研究中添加的无机填料主要有SiO_2、Al_2O_3、ZrO_2、TiO_2等,以Fe_3O_4作为填料的研究尚不多见;Fe_3O_4不仅具有良好的亲水性,而且具有磁性,如果在制膜的过程中引入磁场的作用将改变Fe_3O_4的排列状态,进而会影响膜的结构和性能,但是目前这方面的研究尚未见报道。
本文以聚砜(PSF)为基材,四氧化三铁(Fe_3O_4)为填料,二甲基乙酰胺(DMAC)为溶剂,聚乙烯吡咯烷酮(PVP)为添加剂配制膜液,采用浸没沉淀相转化法分别在有磁场和无磁场的作用下制备了聚砜-四氧化三铁超滤膜。采用错流过滤装置测试了膜的各项性能,用扫描电子显微镜表征了膜的断面和表面结构。结论如下:
(1)在无磁场作用时,Fe_3O_4含量对非磁化超滤膜结构与性能的影响:当Fe_3O_4含量达到30wt%以上时,非磁化膜的截留率均在89%以上;并且随着Fe_3O_4含量的增加,非磁化膜的渗透通量增加,膜断面指状孔贯通性增强,皮层变薄。
(2)在有磁场的作用时,Fe_3O_4含量对磁化超滤膜结构与性能的影响:当Fe_3O_4含量大于30wt%时候,磁化膜的截留率均在90%以上;随着Fe_3O_4含量的增加,磁化膜的渗透通量迅速增加,直到Fe_3O_4含量大于50wt%时,磁化膜的渗透通量不再随着Fe_3O_4含量的增加而增加。当Fe_3O_4含量为70wt%时,磁化膜的综合性能最好,纯水通量和截留率分别为104L/m2·h,95%。电镜图片显示,随着Fe_3O_4含量的增加,磁化膜断面指状孔的贯通性增强。
(3)磁化和非磁化超滤膜结构与性能的差异:当Fe_3O_4含量达到30wt%以上时,在Fe_3O_4含量相同的情况下,磁化膜的渗透通量大于非磁化膜的渗透通量,Fe_3O_4含量越高,磁化膜与非磁化膜的这种差异越明显;直到Fe_3O_4含量达到50wt%以上时,磁化膜和非磁化膜的这种差异开始缩小。相对于非磁化膜而言,磁化膜的断面指状孔的贯通性较好。磁化膜表面呈山峰状结构,这种结构有利于提高磁化膜单位表面积上的微孔数目。
总之,结果表明增加超滤膜中Fe_3O_4的含量可以提高超滤膜的综合性能,如果在制膜过程中引入磁场的作用,将会使超滤膜的综合性能进一步提高。
This paper introduced the principle of UF, and expressed application and existing problems of UF as well as the methods of anti-fouling of membrane and the current research of organic - inorganic membranes. According to many studies, if adding inorganic-fillers, the anti-fouling and permeability of membrane can be improved, and also, mechanical strength, and the lifetime of membrane can be enhanced. And at present, in the research of organic-inorganic UF membrane, the main inorganic-fillers are SiO_2、Al2O_3、ZrO_2、TiO_2 and so on. Fe_3O_4 as a kind of inorganic-filler has seldom been used. Fe_3O_4 is not only excellently hydrophilc but also magnetic. If introducing magnetic effect, the form of Fe_3O_4 would be changed, so that the structure and properties of membrane can be influenced further. This research has not been reported until now.
In this paper, PSF-Fe_3O_4 membrane was prepared by substrate material of PSF, the filler of Fe3o4, the solution of DMAC and the porogen of PVP under magnetic field or nonmagnetic field through the method of immersion precipitation phase inversion. The performance was investigated using cross-flow filtration equipment. The cross-sectional structure of the membranes was observed by SEM. The conclusions are as following:
(1) The influence of the concentration of Fe_3O_4 to the performance and structure of non-magnetic UF membrane: When the concentration of Fe_3O_4 above 30wt%,the rejection of non-magnetic membrane above 89%, increasing the concentration of Fe_3O_4 can not only increase the infiltration flux, but also can enhance the connectivity of the finger-pore , the cortex become thinner with the concentration of Fe_3O_4 increased .
(2) The influence of the concentration of Fe_3O_4 to the performance and structure of magnetic UF membrane: as the concentration of Fe_3O_4 reaching more than 30wt%, the rejection of magnetic membrane was above 90%, increasing the concentration of Fe_3O_4 can increase the infiltration flux of magnetic membrane rapidly, when the concentration of Fe_3O_4 above 50wt%, the infiltration flux of magnetic membrane will not enhance with the concentration of Fe_3O_4 increased. As the concentration of Fe_3O_4 reaching 70wt%, the synthetically properties of magnetic membrane was the best, the pure water flux and rejection are respectively 104L/m2·h and 95% at this time. The SEM pictures of the cross-sectional of magnetic membrane indicated that the connectivity of the finger-pore was enhanced with the concentration of Fe_3O_4 increased.
(3) The differences of UF membrane structure and performance between magnetic membrane and non- magnetic membrane :under the condition that the concentration of Fe_3O_4 reaching more than 30wt%, when we have the same Fe_3O_4 concentration, the infiltration flux of magnetic membrane is higher than the magnetic membrane’s. The phenomenon is more obvious when the concentration of Fe_3O_4 is higher. Comparing non-magnetic membrane, the connectivity of the finger-pore is better in magnetic membrane. The magnetic-membrane surface was mountain-like structure which is propitious to increase porosity of probability on the surface of magnetic- membrane.
In conclusion, the result indicated that increasing the concentration of Fe_3O_4 can enhance the synthetically properties of UF membrane. If we introducing the effect of magnetic field, the synthetically properties of UF membrane will be improved further.
引文
[1]刘茉娥等.膜分离技术.化学工业出版社,1998:17-33.
[2] Smith J. C. V., et al. The Use of Ultrafiltration Membrane for Activated Sludge Separation. Presented Paper of 24th Annual Purdue Industrial Waste Conference, 1969:23-30.
[3]何义亮.膜生物反应器技术处理污水的特性研究.同济大学博士学位论文, 1999:78-89.
[4]陆晓千,余志荣,陆斌.超滤法处理切削乳化液废水的研究与应用[J].工业水处理, 1999, 19(9):28-29.
[5]李永发,李阳初等.含油污水的超滤法处理[J].水处理技术,1995, 21(3):45-48.
[6]温建志,王生春中空纤维膜在油田水处理中的应用[A].第三届全国膜和膜过程学术报告会论文集, 1999:464-461.
[7]梁立军.大庆油田回注水过滤净化研究[J].膜科学与技术,1998, 18(2).
[8]任建新.膜分离技术及其应用[M ].北京:化学工业出版社, 2003.
[9]商莉,魏爱军.超滤技术在汽车车身涂装中的应用[J].汽车工艺与材料,1995, 7:42-43.
[10]纪海霞。超滤污水深度处理特性及膜污染机理研究[D]。西安建筑科技大学,2003.
[11] Wakenman R. J., Akay G.. Membrane-solute and liqiud-particle interaction effects in filtration. Filter. &Separ. 34(4):511-519, 1997.
[12] Hlavacek M., Bouchet F.. Constant flow rate blocking laws and an example of their application to dead-end micro filtration of protein solutions. J. Membre. sci. 82:285-295, 1993.
[13] Xing C. H., Tardieu E., Qian Y., et al. ULtrafiltration membrane bioreactor for urban waster reclamation. J. Membr. sci. , 17773-82, 2003.
[14]路平,李忠铭,王敏娟等.膜分离技术在造纸废液中应用研究进展[J].湖北化工, 2001, 5:8-10.
[15]朱昉.浅谈膜分离技术及其在制浆废水处理中的应用[J].林产工业, 2002, 29(2):44-46.
[16]昌盛,聂幼华.膜技术在乳品工业中应用的最新进展[J].食品与机械, 1997(5):9-11.。
[17]张玉忠,郑领英,高从锴.液体分离膜技术及应用[M].北京:化学工业出版社,2004. 315-316.
[18]毕海丹,崔旭海等.膜技术在乳品工业中应用的最新进展[J].食品与机械, 1997(5):9-11.
[19]刘昌胜,邬行彦,潘德维,林剑.膜科学与技术膜的污染及其清洗[J].膜科学与技术, 1(2):25-30.
[20]邱运仁,张启修.超滤过程膜污染控制技术研究进展[J].现代化工,2002,22(2):18-21
[21] Srijaroonrat P., Julien E. , Aurelle Y.. Unstable secondary oil/ water emulsion treatment using ultrafiltration :fouling control by backflushing[J] . J. Membr. Sci. , 1999 , 159 (1) :11-20.
[22] Nameri N., Oussedik S., Yeddou R., et al . Enhancement of ultrafiltration flux by coupling static turbulence promoter and electric field[J]. Seperation and Purification Technology, 1999, 17(3):203-211.
[23] Zumbush P. V., Kulcke W., Brunner G.. Use of alternating electrical fields as anti-fouling strategy in ultrafiltration of biological suspensions-introduction of a new experimental procedure for crossflow filtration[J] . J. Membr. Sci. , 1998 , 142 (1) :75-86.
[24] Kobayashi T., Fujii N. . Effect of ultrasound on enhanced permeability during membrane water treatment[J]. Japanese Journal of Applied Physics , 2000 , 39(5):2980-2981.
[25] Chai X. J., Kobayashi T., Fujji N.. Ultrasound-associated cleaning of polymeric membranes for water treatment [J]. Separation and Purification Technology , 1999, 15(2):139-146
[26] Mulder M.. Basic Principles of Membrane Technology (Second Edition). Dordrech[M]. Kluwer Academic Publishers, 2003.
[27]姜云鹏,王榕树.纳米SiO2/PVA复合超滤膜的制备及性能研究[J].高分子材料科学与工程, 2002, 18(5):177-180.
[28]姜云鹏,王榕树.纳米SiO2一聚乙烯醇复合超滤膜的制备及应用[J].工业水处理, 2002, 22(5):12-14.
[29]何涛,江成璋.聚醚砜微孔膜制备中非溶剂添加剂作用研究.膜科学与技术,1998,18(3):43-48.
[30] Wilhelm F. C., Pant L. G. M..Canon permeable membranes from blends of sulfonated poly(etherether ketone)and poly(ether sulfone)[J]. J. Mernbr. Sci. , 2002, 199(1-2):167-176.
[31] Marchese J.,Ponce M.,Ochoa N. A.,et al..Fouling behaviour of polyethersulfone of membranes made with different PVP[J]. J. Mernbr. Sci. , 2003, 211(1):1-11.
[32]孙俊芬,王庆瑞.关于聚醚砜膜的研究进展[J].合成技术及应用,2006, Vo1. 16(1):19-22.
[33]王国建,王公善.功能高分子[M].上海同济大学出版社,1996, 16(1):48-57.
[34]陈坚锐,黄加乐,董声雄. PES超滤膜的制备工艺条件及化学稳定性研究.沈阳化工学院学报,2002, 16(4):294-298.
[35]卜海军,陈鸣才,许凯.倒相法制备聚偏氟乙烯多孔膜大孔的研究[J].精细化工,2005, 2(2):99-102.
[36]黄征青.聚丙烯腈/四氧化三铁超滤膜的结构、性能及正交磁场的影响[D].武汉,华中科技大学.,2006.
[37] Bottino G., Capannelli V., Dasti,et al. .Preparation and properties of novel organic–inorganic porous membranes[J].Sep.Purif.Technol.,2001,22-23: 269-275.
[38] Wara N. M., Francis L. F., Velamakanni B. V.. Addition of alumina to cellulose acetate membranes[J]. J.Membr.sci.,1995,104:43–49.
[39] GennéI., Leysen R.. Effect of the addition of ZrO2 to polysulfone based UF membranes[J]. J.Membr.sci.,1996,113:343–350.
[40] Doyen W., Adriansens W., et al.. Organomineral ultrafiltration membranes[J]. Filtr. Sep.,1997,4:964-973.
[41] Doyen W., Adriansens W., B. Molenberghs, et al.. Acomparison between polysulfone, zirconia and organo-mineral membranes for use in ultrafiltration[J],J. Membr. sci.,1996,113:247-258.
[42] Aerts P., Hoof E. V., Leyse R.et al. .Polysulfone–Aerosil composite membranes. Part 1. The influence of the addition of Aerosil on the formation process and membranemorphology[J].J.Membr.sci.,2000,176:63–73.
[43] Aerts P., Genne I., Kuypers S., et al. .Polysulfone–aerosil composite membranes. Part 2. The influence of the addition of aerosil on the skin characteristics and membrane properties[J]. J.Membr.sci.,2000,178:1-11.
[44] Rsyz J.,Luciak M.,Kedziora J.,Blaszcyk J.,Sibinska E.. Nitric oxide release in the peripheral blood during hemodialysis[J]. Kid. Int.,1997,51(1):294-300.
[45] Brendolan A.,Cappelli G..In vitro and in vivo evaluation of a new polysulfone membrane for hemodialysis. methodology and clinical results(Part. 2 : In vivo study)[J].Art.Org.,1999,22(9):616-624.
[46] Torto N.,watseteza M.,Sawula G..A study of microdialysis sampling of metal ions[J].Analy Chim.Acta.,2002.456(2):253-261.
[47] Desa H. M.,Freitas L. A.,Alves V. C.,Garcao M. F.,Rosa M. A..Platel and endotheliala ctivation in patients with acute renal failure treated by Intermittent hemodialysis[J]. A.mer. J. Nepbr. ,2001,21(4):264-273.
[48] Wang M.,Hickner M.,Kim Y. S.,Zawodzinski T. A.,James E. M.. Direct polymerization of sulfonated poly(arylene ether sulfone) random (statistical) copolymers:candidate for new proton exchange membranes[J]. J. Membr. Sci.,2002, 197(1-2):231-242.
[49] Cui W. , Kerres J.. Eigenberger G Development and characterization of ion-exchang Polymer blend membranes[J]. Sep. Pur. Tech.,1998,14:140-154.
[50]张伟,戴干策,Kerres J..改性聚砜交联离子交换膜的合成[J].高分子学报, 1998(5):608-611.
[51] Zhang X.P.,Liu S.Z., Yin J.. Selectively sulfonated poly(aryl ether sul fone)-b-p olybutadiene for proton exchange membrane[J]. Polym. Sci. , Part B:Polym. Phys. . 2006,44(4):665-672.
[52] Gander M. A., Jeferson B., Judd S. J.. Membrane materials and effluent quality[J]. Wat. Sci. Tech.,2000,41(1:205-211.
[53] Han M.J.,Lee K. W.,Seo B. K.. Preparation and characterization of adouble-layered Porous film to assay for surface radioactive contamination[J]. J. Membr. sci. , 2003,223(1-2):59-67.
[54] Lee K. W. , Seo B. K., Lim N. J. ,Nam S. T. ,Han M. J. . Efect of nonsolvent coagulant on the morphology and radionuclide detection eficiency of CAYS- Impregnated polysulfone films[J]. A. ppl. Polym. Sci.,2006,99(4):1903-1909.
[55] Seo K., Kim S. K. ,Lee K. W. ,Park J. H. ,Lim K. H. ,Han M. J. .The measurement of radioactive surfacec ontamination using an inorganic fluor-impregnated membrane :Proceedings of the 9th International Conference on Radioactive Waste Management and Environmental Remediation[J]. Session(38). Korea:ICEM,2003.
[56] Bhattacharya R.,Phanimj T. N.,Shailaja D..Polysulfone and polyvinyl pyrrolidoneblend membranes with reverse phase morphology as controlled releases ystems:experimental and theoretical studies[J]. J. Membr. sci. , 2003, 227(1-2):23-37.
[57]龚琦,陈坚锐,曾振辉,彭海媛,汀美珍,董声雄.用于复合纳滤膜的PAN基底膜的改性及性能表征[J].福州人学学报(自然利学版), 2004, 32(2):242-245.
[58]张裕卿,丁建.聚砜-Al2O3复合膜的制备及表征[J].天津理工学院学报,1999,15(4).
[59] Vankelecom,De Beukelaer.Uytterhoeven[M].Phys. Chem.,1997,101:5186.
[60] Tong P.S.,Barbano D. M.,Rudan M. A..Characterisation of proteinaceous membrane foulants and flux decline during the early stages of whole milk filtration[J]. Dairy Sci.,71(1988)604-624.
[61] Jaffrin M. Y.,Ding L. H.,Defossez M.,Laurent J. M..Interpretation of transient ultrafiltration and microfiltration of blood and protein solutions[M]. Chem. Eng. ci.,6(1995)907.