Department of Chemical Technology, Midlands State University, Private Bag 9055, Senga, Gweru, Zimbabwe.
Environ Monit Assess. 2017 Jan;189(2):47. doi: 10.1007/s10661-016-5728-y. Epub 2017 Jan 3.
The use of cowpea pod (CPP) biomass for the removal of Pb(II) ions from aqueous solution was investigated. The effects of factors such as dosage concentration (0.2 to 1.6 g L), pH (2 to 8), contact time (5 to 120 min), metal ion concentrations (10 to 80 mg L) and temperature (20 to 50 °C) were examined through batch studies. The biosorption data conformed best to the Langmuir model at the three working temperatures (20, 30 and 40 °C) as revealed by the correlation coefficients (R ) which were greater than 0.940. The maximum sorption capacity of the CPP for Pb(II) was 32.96 mg g at 313 K. Furthermore, the kinetic data fitted well to the pseudo-second-order model as it had the lowest sum of square error (SSE) values and correlation coefficients close to unity (R > 0.999). The thermodynamic parameters (ΔG°, ΔS° and ΔH°) showed that the biosorption process was spontaneous, feasible and endothermic. The results obtained in the present study indicated that cowpea pod biomass could be used for the effective removal of Pb(II) from aqueous solution.
采用豇豆荚（CPP）生物质从水溶液中去除 Pb(II)离子。通过批量实验考察了剂量浓度（0.2 至 1.6 g/L）、pH 值（2 至 8）、接触时间（5 至 120 分钟）、金属离子浓度（10 至 80 mg/L）和温度（20 至 50°C）等因素的影响。在三个工作温度（20、30 和 40°C）下，吸附数据最符合 Langmuir 模型，相关系数（R）大于 0.940。CPP 对 Pb(II)的最大吸附容量为 313 K 时的 32.96mg/g。此外，动力学数据非常符合准二级模型，因为它具有最低的平方和误差（SSE）值和接近 1 的相关系数（R>0.999）。热力学参数（ΔG°、ΔS°和ΔH°）表明，吸附过程是自发、可行和吸热的。本研究结果表明，豇豆荚生物质可用于从水溶液中有效去除 Pb(II)。
