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以壳聚糖和不溶性腐殖酸为原料,采用滴加成球法制备了一种新型重金属离子吸附剂——壳聚糖交联不溶性腐殖酸,对其进行了物理性质测定及FT-IR、SEM等分析。研究了吸附剂对水溶液中Pb(Ⅱ)的吸附特征。吸附等温线分别以Freundlich和Langmuir方程进行拟合,结果显示,吸附的最佳模型为Freundlich吸附模型。利用该方程拟合的数据,由Clausius-Claperyon’s方程计算出的Pb(Ⅱ)吸附焓变值,说明吸附剂对Pb(Ⅱ)的吸附以化学吸附为主。利用吸附剂吸附Pb(Ⅱ)前后的XPS分析了吸附机理,同时考察了温度、p H值及吸附时间对吸附效果的影响。结果表明,随着温度的升高和pH值的增大,吸附剂对Pb(Ⅱ)的吸附量增加,而且吸附更符合准二级动力学模型。
Using chitosan and insoluble humic acid as raw materials, a new type of heavy metal ion adsorbent-chitosan cross-linked insoluble humic acid was prepared by drop-spheronization method. The physical properties and FT-IR , SEM and other analysis. Adsorption characteristics of Pb (Ⅱ) in aqueous solution were studied. The adsorption isotherms were fitted by Freundlich and Langmuir equations, respectively. The results showed that the best adsorption model was Freundlich adsorption model. Using the data fitted by this equation, the change of adsorption enthalpy of Pb (Ⅱ) calculated by Clausius-Claperyon’s equation shows that the adsorption of Pb (Ⅱ) on the adsorbent is dominated by chemisorption. The adsorption mechanism was analyzed by XPS before and after the adsorption of Pb (Ⅱ) on the adsorbent. The effects of temperature, pH value and adsorption time on the adsorption were also investigated. The results showed that with the increase of temperature and pH, the adsorbent adsorbed Pb (Ⅱ) increased, and the adsorption was more in line with the quasi-second-order kinetic model.