Fe0-PDADMAC/PAA复合膜还原降解酸性红B

Reductive degradation of ARB by Fe^0-PDADMAC/PAA composite membrane

为获得能够均匀分散和稳定固定Fe0的复合膜材料,以实现Fe^0的高反应活性,同时抑制Fe^0钝化,以聚丙烯腈(PAN)平板膜作为基膜材料,采用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-亚铁离子的配位作用以及经典液相还原法制备复合膜(Fe^0-PDADMAC/PAA)n.利用扫描电镜(SEM)和X-射线光电子能谱(XPS)对膜表面的形貌和化学成分进行表征,并采用该复合膜对水体中的酸性红B(ARB)进行还原降解.结果表明:复合膜的组装层数n=1、3、5、7、9时,复合膜中铁的含量分别为25.7、77.6、114.0、151.7、171.4 mg/g;溶液p H值在2.5~5.5范围内,复合膜对ARB的还原降解率为85%,反应体系中溶解氧的存在对复合膜还原ARB具有较小的抑制;降解反应过程中,Fe^0还原污染物后,单位质量膜上Fe的溶出量均小于0.1 mg/g,说明Fe离子能够较好地稳定固定在复合膜中.

In order to obtain the Fe0 with high dispersity and stability on the composite membrane and make Fe0 on the composite membrane possess the characteristic of high activity and less pssivation, the modified PAN flat membranes assembled with polydiallyldimethylammonium chloride （PDADMAC） andpolyacrylicacid （PAA） were successfully prepared via layer-by-layer self-assembling technique. （Fe°-PDADMAC/PAA）？ composite membranes were prepared by coordination of carboxyl and ferrous ion and classical liquid phase reduction method. Further^nore, the scanning electron microscope （SEM） and X- ray photoelectron spectroscopy （XPS） were performed to determine the morphology and chemical composition of the membrane and the composite membrane were used to degrade the Acid Red B （ARB） in water. The results showed that the contents of iron on membrane were 25.7, 77.6, 114.0, 151.7, 171.4 mg/g, while the number of membrane layer （n） was 1 , 3, 5, 7, 9. The removal rate of ARB by （Fe0-PDADMAC/PAA ）n w-as 85% underthe pH value of2.5-5.5. Dissolved oxygen （DO） had no obvious influence on the reductive degradation of ARB. During the degradation, the leak quantities of Fe ion from composite membrane was less than 0.1 mg/g and illustrated Fe ion had good stability on the composite membrane.