柚子皮生物炭对Cd^(2+)的吸附性能研究

Adsorptive Properties of Cd^(2+) with Biological Carbon Prepared from Pomelo Peel

以固废物柚子皮为生物质代表,经炭化改性处理后,考察其对Cd2+的吸附特征。应用红外吸收光谱技术表征柚子皮生物炭表面的功能基团,考察了吸附剂的粒径和用量、Cd2+初始浓度、溶液p H以及吸附时间对吸附性能的影响。研究结果表明,在p H为5.0,吸附时间1 h,温度298 K条件下,0.1 g柚子皮生物炭对100 m L 10 mg/L Cd2+的去除效率达93%,平衡吸附量qe为9.35 mg/g。吸附反应符合动力学二级方程(R=0.993 6)。用Langmuir和Freundlich方程对吸附等温线进行拟合,发现Langmuir模型能更好地反应吸附过程特征。

Low cost and environmental friendly biological carbon derived from the agricultural waste of pomelo peel was evaluated for its ability to remove Cd^2＋ from an aqueous solution in a bath process. The functional groups on the surface of pomelo peel-char were examined by FTIR. The effect of experimental parameters such as absorbate dosage and particle size,solution p H,initial Cd^2＋ concentration and contact time on the adsorption were investigated elaborately. It was found that the p H played a major role in the adsorption process. The adsorption equilibrium can be attained in 1 h. Under the experimental conditions,adsorption kinetics followed the pseudo-second-order equation,with a balance adsorption capacity of 9. 35 mg / g and an adsorption efficiency of93%. Equilibrium experiments were conducted in the range of 10 mg / L initial Cd^2＋ concentrations. The results indicated that equilibrium data fitted well to the Langmuir model.