SA/CS/PVA复合水凝胶的制备和吸附性能

Preparation and Adsorption Performance of PVA-functionalized Sodium Alginate Composite Hydrogels

以海藻酸钠(SA)为原料,添加壳聚糖(CS)后通过静电聚合形成双网络结构,以聚乙烯醇(PVA)作为功能化材料,利用Ca(II)离子交换法制备出一种由PVA改性的海藻酸钠/壳聚糖/聚乙烯醇复合水凝胶(SA/CS/PVA)。研究发现,SA/CS/PVA呈絮状,用于处理pH为7、浓度为120 mg/L的亚甲基蓝(MB)废水时,吸附30 min即可达到平衡,去除率为95.67%,最大吸附量为134.73 mg/g(298 K)。吸附机理包括静电引力和官能团羟基、羧基络合,吸附过程遵循拟一级、拟二级动力学模型,且与Langmuir等温线模型吻合。

A sodium alginate/chitosan/polyvinyl alcohol composite hydrogel(SA/CS/PVA)modified by PVA was prepared from sodium alginate(SA)by adding chitosan(CS)to form a double-network structure with the electrostatic polymerization of SA,and poly(vinyl alcohol)(PVA)as a functionalized material by using Ca(II)ion exchange method.It was found that SA/CS/PVA was in flocculent form,and the adsorption could reach equilibrium in 30 min with the removal rate of 95.67%and the maximum adsorption amount of 134.73 mg/g(298 K)when it was used for the treatment of methylene blue(MB)wastewater with the concentration of 120 mg/L at pH=7.The adsorption process was characterized by the adsorption of hydroxyl and carboxyl groups,and the adsorption process followed the proposed primary and secondary kinetic models.The adsorption mechanism included electrostatic attraction and complexation of functional groups hydroxyl and carboxyl groups,and the adsorption process followed the proposed primary and secondary kinetic model,which was in agreement with the Langmuir isotherm model.