SGO改性复合纳滤膜的制备及分盐性能

Preparation of Sulfonated Graphene Oxide Modified Composite Nanofiltration Membrane and Application in Salts Separation

近年来,水资源短缺,水源污染严重,国家对水处理末端的资源化利用提出了更高的要求,分盐过程也受到越来越多的关注.纳滤膜表面通常带有电荷,可以选择性地透过不同价态的离子.基于纳滤膜表面电荷特性不同,为很好地实现盐的分离,将制备的带有磺酸基团的氧化石墨烯引入到纳滤膜材料中,采用界面聚合法,制备了SGO改性复合纳滤膜. Zeta电位分析表明所制备的复合纳滤膜表面的电荷比不添加SGO的纳滤膜更负;红外光谱分析中酯基基团特征峰的出现表明磺酸基团参与了聚合反应; SEM结构表面,膜表面出现了明显的图灵结构,在0. 2 MPa压力下,纯水通量可达45. 85 L·(m^2·h)-1,对Na2SO4截留率为98. 23%,对Na Cl截留率为24. 93%,10 h运行可以很好地实现对SO_4^(2-)、Cl^-的有效分离,可实现盐的资源化回收.

In recent years,water resources are in short supply and seriously polluted. Increasingly more attention has been paid to the process of salt separation. The surface of the nanofiltration( NF) membrane is usually charged and can selectively allow the permeation of different ions. Based on the different charges on the NF membrane surface,in order to achieve a good separation of salt,the prepared graphene oxide with the sulfonic acid group was introduced into NF membrane material. Additionally,the SGO modified composite NF membrane was prepared by interfacial polymerization. Zeta potential analysis showed that the charge on the surface of the prepared NF membrane was more negative than that of the NF membrane without SGO. The peak of the ester group in the FT-IR analysis indicated that the sulfonate group was involved in the polymerization reaction. A Turing structure present on the surface of the membrane was evident through SEM pictures of the membrane surface. At a pressure of 0. 2 MPa,the pure water flux can reach 45. 85 L·( m2·h)-1. The rejection of Na2SO4 was 98. 23%,while that of NaCl was 24. 93%. The 10 h operation can effectively separate SO42- and Cl-,which realized the salt recycling.