National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Sindh 76080, Pakistan.
J Hazard Mater. 2010 Jun 15;178(1-3):941-8. doi: 10.1016/j.jhazmat.2010.02.028. Epub 2010 Feb 17.
In present study a biomass derived from the stem of Acacia nilotica has been investigated to remove As ions from surface water samples of different origins (lake, canal and river). The effects of various parameters viz. pH, biosorbent dosage, contact time and temperature on the biosorption processes were systematically studied. Experimental data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. It was observed that As biosorption best fitted to the Langmuir and Freundlich isotherms. The mean sorption energy (E) calculated from D-R model, indicated physico-chemical biosorption. Study of thermodynamic parameters revealed the endothermic, spontaneous and feasible nature of biosorption process. The pseudo-second-order rate equation described better the kinetics of As biosorption with good correlation coefficients than pseudo-first-order equation. The biomass of A. nilotica was found to be effective for the removal of As with 95% sorption efficiency at a concentration of <200 microg/L of As solution, and thus uptake capacity is 50.8 mg As/g of biomass. The A. nilotica biomass could be used as a low-cost biosorbent for As ion removal.
在本研究中，研究了一种源自金合欢茎的生物质，以去除来自不同来源（湖泊、运河和河流）的地表水样品中的砷离子。系统研究了各种参数（如 pH 值、生物吸附剂剂量、接触时间和温度）对生物吸附过程的影响。实验数据通过 Langmuir、Freundlich 和 Dubinin-Radushkevich（D-R）等温线进行了建模。结果表明，砷的生物吸附最符合 Langmuir 和 Freundlich 等温线。从 D-R 模型计算的平均吸附能（E）表明了物理化学的生物吸附。热力学参数的研究表明，生物吸附过程是吸热的、自发的和可行的。与准一级方程相比，准二级速率方程更能很好地描述砷生物吸附的动力学，相关系数也更高。在浓度低于 200μg/L 的砷溶液中，金合欢的生物质对砷的去除率达到 95%，吸附效率为 50.8mg As/g 生物质，因此金合欢的生物质可作为去除砷离子的低成本生物吸附剂。
