Ni^(2+)生物吸附动力学及吸附平衡研究

Kinetics and Equilibrium of Ni^(2+) Biosorption by Waste Biomass of Saccharomyces cerevisia

研究了金属离子Ni2+在酿酒酵母上的生物吸附特性,内容包括生物吸附动力学和吸附等温线.生物吸附动力学结果表明,当Ni2+初始浓度为65.6 mg/L时,Ni2+在酿酒酵母上的生物吸附可以分为2个阶段,第1阶段为物理吸附,在10 min内快速达到平衡.Ni2+在酵母上的吸附过程可以很好地用准二级动力学方程来描述(R2=0.999),动力学参数k2为0.018 4g/(mg.min),qe为5.96 mg/g.吸附等温线结果表明,Ni2+在酿酒酵母上的生物吸附可以用Langmuir和Freundlich方程来描述,最大吸附量qmax为6.32 mg/g.酿酒酵母可用于处理低浓度的含Ni2+废水.

The biosorption characteristics of Ni^2＋ by the waste biomass of Saccharomyces cerevisia were investigated, including the biosorption kinetics as well as equilibrium isotherm study. The experimental results showed that when the initial Ni^2＋ concentration was 65.6 mg/L, the process of Ni^2＋ biosorption onto the biomass of Saccharomyces cerevisia could be divided into two stages, the first stage was physical sorption and reached equilibrium very quickly （within 10 minutes）. The biosorption kinetics could be described by the pseudo second-order equation quite well （ R^2 = 0.999）, and the kinetic parameters k2 and qe were 0.018 4 g/（mg·min） and 5.96 mg/g, respectively. The equilibrium isotherm could be fitted by the Langmuir and Freundlich models, with the maximum biosorption capacity of 6.32 mg/g. The removal of Ni^2＋ from wastewater by biosorption is feasible.