两性离子超分子水凝胶的制备及对废水中阴/阳离子染料的吸附去除

Preparation of zwitterionic supramolecular hydrogel and removal of anionic/cationic dyes from wastewater by adsorption

以三聚氯氰和5-氨基间苯二甲酸为原料,通过亲核取代制备了一种新型耐盐两性离子超分子水凝胶(ZSH)2,4,6-三(3,5-二羧基苯基氨基)-1,3,5-三嗪。运用FTIR、NMR、MS和SEM技术对ZSH进行了表征,并将其用于对阴离子染料活性艳红(K-2BP)和阳离子红(X-GTL)的吸附去除。基于ZSH的pH响应性和耐盐性,在高盐染料废水中利用ZSH的原位溶胶-凝胶转变,可在其与阴/阳离子染料接触的瞬间完成吸附。当吸附pH为0.86、ZSH与K-2BP的质量比为5∶2时,K-2BP的去除率可达89.6%,饱和吸附量为459.2 mg/g;当吸附pH为1.00、ZSH与X-GTL的质量比为2∶1时,X-GTL的去除率可达91.8%,饱和吸附量为427.6 mg/g。ZSH吸附K-2BP和X-GTL的过程更符合Freundlich等温吸附模型。

A new salt-tolerant zwitterionic supramolecular hydrogel(ZSH)2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine was prepared from cyanuric chloride and 5-aminoisophthalic acid by nucleophilic substitution.The ZSH was characterized by FTIR,NMR,MS and SEM and used for the adsorption and removal of anionic dye reactive brilliant red(K-2BP)and cationic dye cationic red(X-GTL).Based on the pH responsiveness and salt tolerance of ZSH,the in situ sol-gel transition of ZSH can be utilized in high salt dye wastewaters,where adsorption can be accomplished at the moment of its contact with the anionic/cationic dye.When the adsorption pH is 0.86 and the mass ratio of ZSH to K-2BP is 5∶2,the removal rate of K-2BP can reach 89.6%and the saturated adsorption capacity is 459.2 mg/g;When the adsorption pH is 1.00 and the mass ratio of ZSH to X-GTL is 2∶1,the removal rate of X-GTL can reach 91.8%and the saturated adsorption capacity is 427.6 mg/g.The process of K-2BP and X-GTL adsorption on ZSH is more in line with the Freundlich isothermal adsorption model.