Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha, India.
Department of Botany and Biotechnology, Ravenshaw University, Cuttack, Odisha, India.
Environ Sci Pollut Res Int. 2021 Nov;28(42):58885-58901. doi: 10.1007/s11356-021-13026-1. Epub 2021 Feb 27.
Biosorption is an ingenious technique that uses biological materials to acquire trace metal ions from wastewater. In the present study, the ability of Colocasia esculenta stem biomass was explored for the biosorption of toxic trace metals. The maximum removal was observed for arsenate (As) with 58.63%, followed by chromium (Cr) with 56.56%, and cadmium (Cd) with 41.2%. However, for copper (Cu), nickel (Ni), and zinc (Zn), low adsorption was observed. Batch sorption tests revealed that adsorbent dosage of 0.5g, 0.5g, and 0.3g; time of 10 h, 4 h, and 10 h; room temperature range of 25-30°C; pH range of 7.0-4.5; and initial concentration of 30 μg/L, 20 mg/L, and 30 mg/L were the optimum conditions for the removal of As, Cr, and Cd, respectively. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDX) analysis of Colocasia esculenta stem biomass before and after adsorption revealed that the trace metals successfully get adsorbed on the surface of the biosorbent. The equilibrium data fitted well with the adsorption isotherm model of Langmuir (for As, Cr, and Cd), Dubinin-Radushkevich (for As and Cr), and Flory-Huggins (for Cd), and the kinetic data of As, Cr, and Cd biosorption were best described by pseudo-second-order kinetic model. Thermodynamic studies revealed that the adsorption process for all concerned trace metals acts in a spontaneous manner and is endothermic in nature. Thus, the use of Colocasia esculenta stem biomass proved to be an efficient and economical alternative for the treatment of effluents contaminated with these trace metals.
生物吸附是一种巧妙的技术，利用生物材料从废水中获取痕量金属离子。本研究探索了芋艿茎生物质对有毒痕量金属的吸附能力。最大去除率观察到砷酸盐（As）为 58.63%，其次是铬（Cr）为 56.56%，镉（Cd）为 41.2%。然而，对于铜（Cu）、镍（Ni）和锌（Zn），吸附率较低。批处理吸附实验表明，吸附剂用量为 0.5g、0.5g 和 0.3g；时间为 10h、4h 和 10h；室温范围为 25-30°C；pH 值范围为 7.0-4.5；初始浓度为 30μg/L、20mg/L 和 30mg/L 分别为去除 As、Cr 和 Cd 的最佳条件。芋艿茎生物质吸附前后的扫描电子显微镜和能谱分析（SEM-EDX）表明，痕量金属成功地吸附在生物吸附剂表面。平衡数据与 Langmuir（As、Cr 和 Cd）、Dubinin-Radushkevich（As 和 Cr）和 Flory-Huggins（Cd）吸附等温线模型拟合良好，As、Cr 和 Cd 吸附的动力学数据最好由伪二级动力学模型描述。热力学研究表明，所有相关痕量金属的吸附过程都是自发的，本质上是吸热的。因此，芋艿茎生物质的使用被证明是处理这些痕量金属污染废水的有效且经济的替代方法。
