零价铁复合膜制备及对有机污染物的催化还原效能

发布时间：2018-05-12 19:52

本文选题：层层自组装技术 + 配位作用　；参考：《天津工业大学》2017年硕士论文

【摘要】：本文采用聚丙烯腈(PAN)平板膜作为基膜材料,通过静态层层自组装技术制备聚二烯丙基二甲基氯化铵(PDADMAC)、聚丙烯酸(PAA)组装聚电解质复合膜,再经过羧基-亚铁离了的配位作用以及经典液相还原法制备(Fe~0-PDADMAC/PAA)n复合催化膜。用于水体中亚硝基二甲胺(NDMA)和酸性红染料(ARB)的还原转化研究。研究中,FTIR分析发现增强基膜表面亲水性和荷电性,有利于后续的聚电解质在膜表面的组装;扫描电镜图显示复合膜表面的零价铁分散均匀,粒径在200nm左右;紫外分析可知,层数n==,3,5,7,9时,复合膜中铁的含量分别为 25.7,77.6,114,151.7,171.4 mg·g-1;XPS 和 XRD 数据分析表明,零价铁与有机污染物反应后,零价铁转化为Fe3+/Fe2+,并主要以Fe203和Fe3O4存在于膜表面上。在研究复合膜对NDMA和ARB还原转化过程中发现,反应初期的反应速率较快,后期达到平稳,反应时间较短。(Fe~0-PDADMAC/PAA)9对于初始浓度为150μg·L-1的NDMA溶液的去除效率为65.8%,对于初始浓度为100mg·L-1的ARB溶液的去除效率接近100%。pH值、反应温度和共存离子等因素均对污染物的去除有一定的影响。(Fe~0-PDADMAC/PAA)n复合催化膜中的Fe~0氧化释放电子,使得氢原子活化,与目标污染物发生还原反应,达到降解去除的作用。研究表明降解反应过程中,Fe还原污染物后,单位质量膜上Fe的溶出量均小于0.1mg·g-1。复合膜表面具有的羧基与还原反应过程中生成的铁离子再次络合,将铁离子继续固定在PAN膜上。
[Abstract]:In this paper, polyacrylonitrile (PAN) flat film was used as the base film material, and the polydiallyl dimethyl ammonium chloride (PDADMAC), polyacrylic acid (PAA) polyelectrolyte composite film was prepared by static layer self-assembly technique. The Fe0-PDADMAC / PAA _ (n) composite catalytic membrane was prepared by the coordination of carboxyl-ferrous ionization and the classical liquid-phase reduction method. It was used to study the reduction and transformation of nitrosodimethylamine (NDMA) and acid red dye (ARB) in water. FTIR analysis showed that the enhancement of the hydrophilicity and charge-resistance of the substrate surface was beneficial to the subsequent assembly of polyelectrolytes on the membrane surface, and the scanning electron microscopy showed that the zero-valent iron on the surface of the composite film was uniformly dispersed and the particle size was about 200nm. The iron content in the composite membrane was 25.77.6114151.7mg / g ~ (-1) and 171.4 mg / g ~ (-1) XRD, respectively. The results showed that after the reaction of zero-valent iron with organic pollutants, the zero-valent iron was converted to Fe3 / Fe _ 2 and mainly existed on the surface of the film as Fe203 and Fe3O4. In the study of the reduction and conversion of NDMA and ARB by the composite membrane, it was found that the reaction rate was relatively fast at the initial stage of the reaction, and the reaction rate was stable at the later stage. The removal efficiency of NDMA solution with initial concentration of 150 渭 g 路L ~ (-1) was 65.8%, and the removal efficiency of ARB solution with initial concentration of 100mg ~ (-1) was close to 100%.pH value. Factors such as reaction temperature and co-existing ions have a certain effect on the removal of pollutants. The oxidation and release of electrons by Fe~0 in the Fe0-PDADMAC / PAA _ (n) composite catalytic membrane lead to the activation of hydrogen atoms and the reduction of hydrogen atoms with the target pollutants, so as to achieve the effect of degradation and removal. The results showed that the amount of Fe dissolved on the film was lower than that of 0.1mg g ~ (-1). The carboxyl group on the surface of the composite membrane was recomplexed with the iron ions produced during the reduction reaction, and the iron ions were immobilized on the PAN film.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;X703

【参考文献】