Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Sungai Long Campus, Jalan Sungai Long, Cheras, 43000, Kajang, Selangor, Malaysia.
Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Sungai Long Campus, Jalan Sungai Long, Cheras, 43000, Kajang, Selangor, Malaysia; Centre for Photonics and Advanced Materials Research, Universiti Tunku Abdul Rahman, Sungai Long Campus, Jalan Sungai Long, Cheras, 43000, Kajang, Selangor, Malaysia.
Chemosphere. 2022 Mar;291(Pt 3):133035. doi: 10.1016/j.chemosphere.2021.133035. Epub 2021 Nov 27.
Heavy metal contamination in water bodies is currently in an area of greater concern due to the adverse effects on human health. Despite the good adsorption performance of biochar, various modifications have been performed on the pristine biochar to further enhance its adsorption capability, at the same time overcome the difficulty of particles separation and mitigate the secondary pollution issues. In this review, the feasibility of chitosan-modified magnetic biochar for heavy metal removal from aqueous solution is evaluated by critically analysing existing research. The effective strategies that applied to introduce chitosan and magnetic substances into the biochar matrix are systematically reviewed. The physicochemical changes of the modified-biochar composite are expounded in terms of surface morphology, pore properties, specific surface area, surface functional groups and electromagnetism. The detailed information regarding the adsorption performances of various modified biochar towards different heavy metals and their respective underlying mechanisms are studied in-depth. The current review also analyses the kinetic and isotherm models that dominated the adsorption process and summarizes the common models that fitted well to most of the experimental adsorption data. Moreover, the operating parameters that affect the adsorption process which include solution pH, temperature, initial metal concentration, adsorbent dosage, contact time and the effect of interfering ions are explored. This review also outlines the stability of modified biochar and their regeneration rate after cycles of heavy metal removal process. Lastly, constructive suggestions on the future trends and directions are provided for better research and development of chitosan-modified magnetic biochar.
水体中的重金属污染由于对人类健康的不利影响，目前是一个备受关注的领域。尽管生物炭具有良好的吸附性能，但为了进一步提高其吸附能力，同时克服颗粒分离的困难并减轻二次污染问题，对原始生物炭进行了各种改性。在本综述中，通过批判性地分析现有研究，评估了壳聚糖改性磁性生物炭从水溶液中去除重金属的可行性。系统地回顾了将壳聚糖和磁性物质引入生物炭基质中所应用的有效策略。从表面形貌、孔性质、比表面积、表面官能团和电磁学等方面阐述了改性生物炭复合材料的物理化学变化。深入研究了各种改性生物炭对不同重金属的吸附性能及其各自的基础机制的详细信息。本综述还分析了主导吸附过程的动力学和等温模型，并总结了适用于大多数实验吸附数据的常见模型。此外，还探讨了影响吸附过程的操作参数，包括溶液 pH 值、温度、初始金属浓度、吸附剂用量、接触时间和干扰离子的影响。本综述还概述了改性生物炭的稳定性及其在重金属去除过程循环后的再生速率。最后，针对壳聚糖改性磁性生物炭的更好研究和开发，提出了建设性的建议和未来的研究方向。
