炭化玉米秸秆对水中Pb(Ⅱ)的去除行为研究

Removal Characteristics of Pb(Ⅱ)on Carbonized Corn Straw(CCS) from Aqueous Solution

以炭化玉米秸秆(CCS)为吸附剂去除水中Pb(Ⅱ),研究反应过程的动力学特性和等温线方程,考察溶液pH值和反应温度对Pb(Ⅱ)去除的影响,分析CCS的解吸行为。结果表明:吸附过程更好地符合准二级动力学方程和Langmuir等温线方程,拟合系数R2分别为0.9972和0.9959;由Langmuir方程计算可知,CCS对Pb(Ⅱ)的理论最大吸附量qm为30.3030mg/g。反应过程自发、吸热,反应后体系自由度略有增加。Pb(Ⅱ)去除的最适pH值为6,对于浓度为40mg/L、体积为100mL的Pb(Ⅱ)溶液,使用0.1g CCS能去除水中63.53%的Pb(Ⅱ)。反应温度对Pb(Ⅱ)去除效果的影响很小。蒸馏水和HCl都能实现Pb(Ⅱ)的有效解吸,再生后的CCS对Pb(Ⅱ)仍能取得15.69mg/g的二次吸附量。

The adsorption kinetics and isotherms for Pb （Ⅱ） on carbonized corn straw （CCS） were studied,the effects of initial pH value and temperature on Pb （Ⅱ）removal were analyzed, and the desorption experiment was investigated. The results showed that the pseudo-second order kinetic equation and Langmuir isotherm equation fit the reaction better, with coefficients of R2 0. 9972 and 0. 9959, respectively. The maximum adsorption capacity was 30. 3030 mg/g. The reaction was endothermic and the optimal removal efficiency was 63.53% at pH 6 for 100 mL Pb（ Ⅱ） solution of 40 mg/L with 0.1 g CCS. The removal effect varied little at different temperatures,and distilled water and HC1 were effective for CCS desorption with an adsorption capacity of 15.69 mg/g for Pb （Ⅱ） on regenerated CCS.