Department of Chemical Engineering, University Teknologi PETRONAS, Seri Iskandar 31750, Malaysia.
Centre of Urban Resource Sustainability, University Teknologi PETRONAS, Bandar Seri Iskandar 32610, Malaysia.
Int J Environ Res Public Health. 2021 Jul 27;18(15):7949. doi: 10.3390/ijerph18157949.
Development of strategies for removing heavy metals from aquatic environments is in high demand. Cadmium is one of the most dangerous metals in the environment, even under extremely low quantities. In this study, kenaf and magnetic biochar composite were prepared for the adsorption of Cd. The synthesized biochar was characterized using (a vibrating-sample magnetometer VSM), Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption batch study was carried out to investigate the influence of pH, kinetics, isotherm, and thermodynamics on Cd adsorption. The characterization results demonstrated that the biochar contained iron particles that help in improving the textural properties (i.e., surface area and pore volume), increasing the number of oxygen-containing groups, and forming inner-sphere complexes with oxygen-containing groups. The adsorption study results show that optimum adsorption was achieved under pH 5-6. An increase in initial ion concentration and solution temperature resulted in increased adsorption capacity. Surface modification of biochar using iron oxide for imposing magnetic property allowed for easy separation by external magnet and regeneration. The magnetic biochar composite also showed a higher affinity to Cd than the pristine biochar. The adsorption data fit well with the pseudo-second-order and the Langmuir isotherm, with the maximum adsorption capacity of 47.90 mg/g.
开发从水生环境中去除重金属的策略的需求很高。镉是环境中最危险的金属之一，即使在极低的数量下也是如此。在这项研究中，制备了麻纤维和磁性生物炭复合材料用于吸附 Cd。使用（振动样品磁强计 VSM）、扫描电子显微镜 (SEM)、X 射线粉末衍射 (XRD)、傅里叶变换红外光谱 (FTIR) 和 X 射线光电子能谱 (XPS) 对合成的生物炭进行了表征。进行吸附批处理研究以研究 pH、动力学、等温线和热力学对 Cd 吸附的影响。表征结果表明，生物炭中含有铁颗粒，有助于改善结构特性（即表面积和孔体积）、增加含氧基团的数量，并与含氧基团形成内球络合物。吸附研究结果表明，在 pH 5-6 下可实现最佳吸附。初始离子浓度和溶液温度的增加导致吸附容量增加。用氧化铁对生物炭进行表面改性以赋予磁性，可通过外部磁铁轻松分离和再生。磁性生物炭复合材料对 Cd 的亲和力也高于原始生物炭。吸附数据与准二级和 Langmuir 等温线拟合良好，最大吸附容量为 47.90 mg/g。
