葡甘聚糖/植物多酚对重金属离子吸附基础研究

Basic Study on Adsorption of Konjac Glucomannan/Plant Polyphenols for Heavy Metals

将具有邻苯三酚结构、能与金属离子形成稳定络合物的植物多酚，通过共价交联的方式将其接枝固化在葡甘聚糖上，制备出可生物降解、对重金属离子具备高吸附容量的功能吸附材料。应用研究结果表明：葡甘聚糖／植物多酚静态吸附重金属离子的时间取211为宜。随着pH值升高，葡甘聚糖／植物多酚对重金属的吸附量增加，pH值在7．0—10．0时，吸附率最高，pH〉10．0以后，葡甘聚糖／植物多酚对重金属的吸附呈下降趋势。葡甘聚糖／植物多酚对重金属离子具有极高的选择性吸附能力。对铅、镉、汞、铬、铜、锌、银等重金属离子的吸附率超过90％；饱和吸附量仉依Zn^2＋〉Hg^2＋〉Ag^＋〉Pb^2＋〉Cu^2＋〉Cr6＋〉Cd^2＋的顺序递减；吸附强度和容量的综合参数K依照Zn^2＋〉Hg^2＋〉Ag^＋〉Pb^2＋〉Cu^2＋〉Cr6＋〉Cd^2＋的顺序递减，说明葡甘聚糖／植物多酚对锌的选择性最好，吸附容量（金属离子／吸附剂）达到150mg／g以上。

The plant polyphenols which contain pyrogallol and can chelate metal ions were solidified to konjac glucomannan by covalent crosslinking to prepare biodegradable functional adsorption materials with high adsorption capacity. The results show that the suitable static adsorption time of heavy metals on konjac glucomannan/plant polyphenols is 2 hours. Along with the increase of the pH values, the absorption amount increases. It reaches the maximum under the pH range of 7.0 - 10.0, after pH 〉 10.0 it decreases obviously. The results also show that konjac glucomannan/plant polyphenols own high selective adsorption for heavy metals. The adsorption ratio of heavy metals on konjac glucomannan/plant polyphenols as Pb, Cd, Hg, Cr, Cu, Zn, Ag, et al. is more than 90%. The saturation adsorption amount Qo decrea- ses as the following orders： Zn^2＋〉Hg^2＋〉Ag^＋〉Pb^2＋〉Cu^2＋〉Cr6＋〉Cd^2＋; integrative parameter （ K ） of absorption intensity and capacity decreases as the following orders ：Zn^2＋〉Hg^2＋〉Ag^＋〉Pb^2＋〉Cu^2＋〉Cr6＋〉Cd^2＋. These indicate that konjac glucomannan/plant polyphenols have the best selectivity for zinc, with the absorption capacity larger than 150mg/g（metal ions/absorbents）.