欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

研究报告

胡勇有
1. 华南理工大学环境科学与工程学院, 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;
2. 华南理工大学制浆造纸工程国家重点实验室, 广州 510640

程建华
1. 华南理工大学环境科学与工程学院, 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;
2. 华南理工大学制浆造纸工程国家重点实验室, 广州 510640

摘要：以壳聚糖和人造沸石为原料,采用滴加成球法制备了一种新型重金属吸附剂——壳聚糖交联沸石小球,通过吸附实验考察了pH值、时间及重金属离子浓度对吸附Cu²⁺、Ni²⁺、Cd²⁺的影响.结果表明,制得的壳聚糖交联沸石小球的平均粒径为3.2 mm,密度为1.08 g · cm^-3,含水率为80%.在pH=5、温度25℃条件下,壳聚糖交联沸石小球对浓度100 mg · L^-1的Cu²⁺、 Ni²⁺和Cd²⁺溶液的饱和吸附量分别达到7.7、8.9和9.1 mg · g^-1,吸附符合准二级动力学模型,吸附过程符合Langmuir等温吸附模型,也基本符合Freundlich等温吸附模型.对于Cu²⁺和Ni²⁺的吸附,壳聚糖交联沸石小球可以再生重复使用5次而吸附量基本无衰减,但对Cd²⁺第5次的吸附量只有初次吸附量的57%.壳聚糖交联沸石小球的电镜扫描结果显示其具有多孔网状结构.

Abstract：Chitosan cross linked zeolite beads, a novel adsorbent for heavy metals, were prepared by dropwise addition of a mixture of zeolite and chitosan into NaOH solution. The effects of reaction time, pH and initial concentration on the adsorption capacity of the beads for Cu²⁺,Ni²⁺ and Cd²⁺ were investigated. The chitosan cross-linked zeolite beads were of an average diameter of 3.2 mm, density of 1.08 g · cm^-3, and water content of 80%. At 25℃, pH 5.0 and initial heavy metal concentration of 100 mg · L^-1,the adsorption capacities of Cu²⁺,Ni²⁺ and Cd²⁺ by chitosan cross-linked zeolite beads were 7.7, 8.9 and 9.1mg · g^-1, respectively. The adsorption process followed pseudo-second-order kinetics and fit both the Langmuir and Freundlich adsorption isotherm models. For Cu²⁺ and Ni²⁺, the chitosan cross-linked zeolite beads could be regenerated, and reused up to 5 times without apparent decrease in adsorption capacity, while in the case of Cd²⁺, only 57% of its original adsorption capacity could be achieved. Scanning electron microscopy of the samples indicated that the chitosan cross-linked zeolite beads had porous network structures.