磁性生物炭去除污染水体中重金属的研究进展

Research Progress on the Removal of Heavy Metals from Polluted Water Using Magnetic Biochars

生物炭在污水中重金属的去除方面具有良好的应用潜力,但由于难以回收、去除效率较低等原因制约了其在工程中的实际应用。采用磁性材料对生物炭进行改性,可大幅提高生物炭的比表面积和吸附能力,且易于回收。本文综述了浸渍—热解法、水热法、共沉淀法、液相还原法四种常用的磁性生物炭制备方法,比较了对不同方法制备的磁性生物炭的吸附性能,总结了磁性生物炭对水体中重金属的吸附机理,分析了生物质种类、热解温度、反应时间、反应温度、溶液pH、磁性生物炭投加量及背景离子浓度七个因素对磁性生物炭吸附性能的影响。最后,展望了磁性生物炭在实际废水处理中的应用前景及存在问题。

Biochar has the potential to be used in the future to remove heavy metals from sewage,but its practical application in engineering is restricted due to the difficulties in recovery,low removal efficiency and other reasons.Biochar modified by magnetic materials can greatly improve its specific surface area and adsorption capacity,and easy to be recovered.In this study,four commonly used preparation methods of magnetic biochar,namely impregnation pyrolysis method,the hydrothermal method,the coprecipitation method,and liquid phase reducing method,were reviewed.The adsorption properties of magnetic biochar prepared using different methods were compared.The adsorption mechanism of magnetic biochar for heavy metals in the water was summarized.The seven influencing factors of the adsorption performance of magnetic biochar,including types of biomass,pyrolysis temperature,reaction time,reaction temperature,solution pH,application dosages,and the concentration of background ions,were analyzed.Lastly,a prospectus was presented outlining the potential applications and current issues with magnetic biochar in real-world wastewater treatment.