水溶液中 MgCl2 改性生物炭去除 Cd 的机理定量分析。
Quantitative analysis on the mechanism of Cd removal by MgCl-modified biochar in aqueous solutions.
机构信息
Guangdong Industrial Contaminated Site Remediation Technology and Equipment, Engineering Research Center, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
College of Engineering, Science and Environment, University of Newcastle, Callaghan, NSW, 2308, Australia; School of Agriculture and Environment, The University of Western Australia, Perth, WA 6001, Australia; The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6001, Australia.
出版信息
J Hazard Mater. 2021 Oct 15;420:126487. doi: 10.1016/j.jhazmat.2021.126487. Epub 2021 Jun 24.
In this study, a pristine biochar (BC) and MgCl-modified biochar (MBC) were prepared using Pennisetum sp. straw for removing Cd from aqueous solutions. Scanning electron microscope (SEM) imaging combined with energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), as well as the surface area and porosity analyses were used to reveal the physico-chemical characteristics of the pristine and modified adsorbents. Results suggested that MgCl impregnation during the synthesis had enhanced the specific surface area and pore volume of the biochar. Batch adsorption experiments indicated that the Cd adsorption data of MBC fitted the Langmuir isothermal and pseudo-second order kinetic models, indicating a chemical adsorption was undergoing in the system. The maximum adsorption capacity of Cd on MBC was 763.12 mg/g, which was 11.15 times higher than that of the pristine BC. The Cd removal by MBC was mainly attributed to the mechanisms in an order: Cd(OH) precipitation (73.43%) > ion exchange (22.67%) > Cd-π interaction (3.88%), with negligible contributions from functional group complexation, electrostatic attraction and physical adsorption. The MBC could thus be used as a promising adsorbent for Cd removal from aqueous solutions.
在这项研究中，使用狼尾草（Pennisetum sp.）秸秆制备了原始生物炭（BC）和 MgCl 改性生物炭（MBC），用于从水溶液中去除 Cd。扫描电子显微镜（SEM）成像结合能谱（EDX）、X 射线光电子能谱（XPS）、傅里叶变换红外光谱（FTIR）以及表面积和孔隙率分析用于揭示原始和改性吸附剂的物理化学特性。结果表明，在合成过程中 MgCl 浸渍提高了生物炭的比表面积和孔体积。批量吸附实验表明，MBC 的 Cd 吸附数据符合 Langmuir 等温线和拟二级动力学模型，表明系统中发生了化学吸附。MBC 对 Cd 的最大吸附容量为 763.12 mg/g，是原始 BC 的 11.15 倍。MBC 去除 Cd 主要归因于以下机制：Cd(OH)沉淀（73.43%）>离子交换（22.67%）>Cd-π 相互作用（3.88%），而官能团络合、静电吸引和物理吸附的贡献可以忽略不计。因此，MBC 可用作从水溶液中去除 Cd 的有前途的吸附剂。
Zotero 插件