【作者】 孙红伟；

【导师】 陈国华；

【作者基本信息】 中国海洋大学 ， 海洋化学， 2007， 硕士

【摘要】 纳滤(Nanofiltration,NF)是自二十世纪八十年代发展起来的介于超滤和反渗透之间的、同属于压力驱动的新型膜分离技术,纳滤的出现填补了超滤和反渗透之间的空白。甲壳素的衍生物具有很好的保湿性、成膜性、生物相容性以及安全无毒性等优点,是一种有广泛应用前景的优良膜材料。本文首次以羟乙基甲壳素为表面活性层材料,分别以环氧氯丙烷(ECH)和甲苯二异氰酸酯(TDI)为交联剂,以聚丙烯腈(PAN)超滤膜为支撑层,制备了两种新型荷负电纳滤膜,并进行了其对纺织印染废水中水的深度处理及回用研究。具体研究内容分以下三个部分:1.环氧氯丙烷交联的羟乙基甲壳素/聚丙烯腈复合纳滤膜的制备及性能研究以聚丙烯腈超滤膜为支撑层,羟乙基甲壳素为活性功能层,并与环氧氯丙烷交联制得一种新型复合纳滤膜,研究了复合膜的制备及操作条件对膜性能的影响,并对复合膜的结构进行了表征。得出复合膜的最佳制备条件为:铸膜液羟乙基甲壳素浓度为1.5wt﹪,交联剂(ECH)浓度为1.0wt﹪,溶剂丙酮溶液(pH 10)浓度为75wt﹪,50℃下烘干2h, 50℃水浴交联为24h,取出50℃下热处理20min。在1.0MPa下测定羟乙基甲壳素/聚丙烯腈复合纳滤膜对1.0 g/L的Na2SO4,K2SO4 , MgSO4 , NaCl,KCl和MgCl2溶液的截留率分别为95.3﹪,91.5﹪,41.0﹪,31.1﹪,31.0﹪和20.1﹪;通量分别为10.0,10.1,19.2,19.7,20.8和13.0 L∕m2·h,制备的复合膜为负电性膜,电压渗系数为-2mV/MPa,截留分子量约为540,膜的孔径为0.73nm,总粗糙度为0.0191μm,平均粗糙度为0.0108μm,溶胀度为46.6%。对不同价型的盐的截留性能可以用道南平衡效应来解释。2.甲苯二异氰酸酯交联的羟乙基甲壳素/聚丙烯腈复合纳滤膜的制备及性能研究以聚丙烯腈超滤膜为支撑层,羟乙基甲壳素为活性功能层,并与甲苯二异氰酸酯交联制得一种新型复合纳滤膜,研究了复合膜的制备及操作条件对膜性能的影响,并对复合膜的结构进行了表征。得出复合膜的最佳制备条件为:羟乙基甲壳素浓度为2.4wt﹪,膜在50℃时烘干时间为2h,交联剂甲苯二异氰酸酯(TDI)浓度为1.3wt﹪,溶剂丙酮和乙醇的配比为(以丙酮所占百分比计算, pH 8)80wt%,交联温度为50℃,交联时间为15h,50℃下热处理5min。在1.2MPa下测定复合纳滤膜对1.0 g/L的Na2SO4,K2SO4 ,MgSO4 ,NaCl,KCl,MgCl2和CaCl2溶液的截留率分别为92.3﹪,90.6﹪,41.1﹪,21.7﹪,19.9﹪,19.6﹪和18.6%;通量分别为4.0,4.9,4.6,5.1,4.8,5.0和5.2 L∕m2·h。制备的复合膜为负电性膜,电压渗系数为-8mV/MPa,截留分子量约为490,膜的孔径为0.67nm,溶胀度为32.8%,复合膜的总粗糙度为0.00985μm,平均粗糙度为0.00934μm。对不同价型的无机盐的截留性能可以用道南平衡效应来解释。3.羟乙基甲壳素/聚丙烯腈复合纳滤膜对纺织印染废水中水的深度处理研究采用环氧氯丙烷交联制备的羟乙基甲壳素/聚丙烯腈复合纳滤膜对纺织印染废水中水进行去除硝酸及亚硝酸盐、CODCr、苯胺、无机盐、脱色和深度脱磷实验,结果表明,在1.5 MPa、40L/h,室温下,经复合纳滤膜处理后,对电导率、苯胺、CODCr去除率分别可达47.0%、67.9%和85.2%,对磷酸盐、硝酸及亚硝酸盐的去除率分别可达97.8%和29.7%,而色度去除率可达100%,出水无色透明,使中水可以回用,减少了水资源的浪费,为中水去除有机物、去除硝酸和亚硝酸盐、脱磷及脱色等深度处理提供了新方法,在水处理方面具有广泛的应用前景。更多还原

【Abstract】 Nanofiltration（NF）, a new type of separation membrane technology developed since 1980’s, is a pressure driven process that forms the transition between ultrafiltration and reverse osmosis, and NF supplied a gap between them.Chitin derivatives are excellent membrane materials with broad application prospects for their good abilities of moisture retention, filming performance, biocompatibility and being nontoxic. In this paper, two novel negatively charged composite membranes are prepared for the first time, whose active layer material is glycolchitin, cross-linking agents are epichlorohydrin （ECH） and diisocyanate （TDI）, supporting layers is polyacrylonitrile（PAN） UF membrane. And also the application of the composite membrane in the treatment and recycling of textile wastewater is studied. The whole paper contains three parts:1. Preparation and characterization of glycolchitin/PAN composite membrane cross-linked by epichlorohydrinA novel composite nanofiltration membrane is fabricated by coating solution of glycolchitin onto PAN UF membrane and subsequently cross-linked by epichlorohydrin （ECH）. Effects of membrane making and operating conditions on performances of the composite membrane are studied, and the structure of the membrane as well. The results suggest that the composite NF membrane with excellent rejection performance should be prepared while glycolchitin concentration is 1.5wt﹪, the membrane is dried for 2h at 50℃, ECH concentration is 1.0wt%, the acetone concentration is 75wt% while pH is 10, then cross-linked for 24h at 50℃, and heat treated for 20 min at 50℃.Rejections of the composite membrane of Na2SO4, K2SO4, MgSO4 , NaCl , KCl and MgCl2 solutions （1.0g?L） are 95.2﹪,91.5﹪,41.0﹪,31.1﹪,31.0﹪and 20.1﹪at 25℃under 1.0MPa;and permeation fluxes are 10.0,10.1 ,19.2,19.7,20.8 and 13.0 L?m2·h, respectively. The electro-osmotic trans- mission coefficient （β） of the negatively charged membrane is about -2mV/Mpa and the molecular weight cut-off is about 540,the pore size is about 0.73nm,the total roughness was 0.0191μm and the average roughness is 0.0108μm, the swelling degree is 46.6%.The results suggested that rejection performance is governed by Donnan effect.2. Preparation and characterization of glycolchitin/PAN composite membrane cross-linked by diisocyanate （TDI）A novel composite nanofiltration membrane is fabricated by coating solution of glycolchitin onto PAN UF membrane and subsequently cross- linked by diisocyanate （TDI）.Effects of membrane making and operating conditions on performances of the composite membrane are studied, and the structure of the membrane as well. The results suggest that the composite NF membrane with excellent rejection performance should be prepared while glycolchitin concentration is 2.4wt﹪, the membrane is dried for 2h at 50℃,TDI concentration is 1.3wt%, the acetone concentration is 80wt% while pH is 8, then cross-linked with TDI for 15h at 50℃,and heat treated for 5min at 50℃. Rejections of the composite membrane of Na2SO4, K2SO4 , MgSO4, NaCl, KCl and MgCl2 solutions （1.0g?L） are 92.3﹪,90.6﹪,41.1﹪,21.7﹪,19.9﹪,19.6﹪and 18.6%;and permeation fluxes are 4.0,4.9,4.6,5.1,4.8,5.0 and 5.2 L?m2·h, respectively. The electro-osmotic transmission coefficient （β） of the negatively charged membrane is about -8mV/Mpa and the molecular weight cut-off is about 490,the pore size is about 0.67nm,the total roughness is 0.00985μm and the average roughness is 0.00934μm, the swelling degree is 32.8%.The results suggest that rejection performance is governed by Donnan effect.3. Study on treatment and recycling of textile wastewater by glycolchitin/PAN composite NF membraneGlycolchitin/PAN composite NF membrane cross-linked by ECH is used in the treatment and recycling of the textile wastewater, including removal of total phosphate,total soluble nitrogen in NO3- and NO2-,CODCr ,aniline,inorganic salt and chroma. The results suggest: when operating pressure is1.5MPa, flux is 40 L/h, the removal rate of inorganic salt,aniline and CODCr are 47.0%,67.9% and 85.2% ,respectively. The rejection to total phosphate and nitrogen in NO3- and NO2- are 97.8%and 29.7%, and the chroma removal rate is nearly 100%.In this way, the textile wastewater can be used again, which avoided the waste of water resource. The method of composite membrane preparation supply a new method for removal of organic matter,total phosphate ,total soluble nitrogen in NO₃^- and NO₂^- and chroma in the sewage. Which is hopeful to apply in water treatment.更多还原