文冠果外皮对水体中锌的去除研究

生物吸附法是最经济有效的去除水体重金属污染的方法.为研究文冠果外皮对水环境中的锌离子的去除效率和去除机理,本文以文冠果外皮为吸附剂,研究了溶液pH值、吸附动力学、锌离子浓度、吸附剂投加量对水溶液中锌的吸附量与去除率的影响;通过模型拟合、离子交换实验和远红外光谱分析(FTIR),对吸附机理进行了探讨.结果表明:文冠果外皮是一种理想的锌吸附剂:适应pH值范围宽(3～6),达到吸附平衡时间短(30 min),吸附容量大(最大值为18.656 mg.g-1),去除效率高(60%～90%);吸附过程符合伪二级动力学模型和Langmuir等温吸附模型.离子交换实验和远红外波普扫描分析表明离子交换和络合反应是主要吸附机理,主要的交换离子为K+,Ca2+,Mg2+和Na+,参与络合、螯合反应的官能团主要有-OH、-NH、-COO-、-C=O.

Biosorption of Zinc by Peel of Xanthoceras sorbifolia Bunge in Water Solution

Biosorption is the most economic and effective method to remove heavy metals from wastewaters. To study the effect of solution pH, biosorption kinetics and equilibrium, adsorbent dosage on removal efficiency, the peel of Xanthoceras sorbifolia Bunge （XB） was adopted as adsorbent to remove aquatic Zn2＋ ions. The adsorption mechanism was analyzed by the model simulations, FTIR and ions exchange experiment. Results shown that the peel of XB was an ideal zinc absorbent by virtue of wide range of pH （3.0 - 6.0）, short equilibrium time （ less than 30 min）, high adsorption capacity （ 18. 656 mg. g-1 ） and high removal efficiency （60% -90% ）. The process of adsorption fitted the pseudo second order kinetics model and Langmuir isotherm model very well. The ions experiment and the FTIR indicated that chemical sorption was the main mechanism （ion exchange and chelation or complexation）. K ＋ , Mg2 ＋ , Na ＋ and Ca2 ＋ was the main exchange cations, and -OH, - NH, - COO- , - C = O worked as functional groups for chelation or complexation with Zn2＋ during the adsorption process.