生物炭吸附水体中重金属机理与工艺研究进展

生物炭因其良好的表面特性和孔隙结构,广泛的原料来源和广阔的产业化发展前景,已成为当今环境、农业和能源等领域的研究热点。针对生物炭对水体重金属的吸附研究,本文基于生物炭原料和制备工艺的多样性,综合分析了国内外生物炭重金属吸附机理的研究成果,详细阐述、分析了5种吸附作用机制(物理吸附、静电作用、离子交换、络合反应和化学沉淀)及其相关表征手段;同时评述了吸附工艺条件和重金属种类对生物炭吸附重金属的影响;指出生物炭重金属吸附领域未来的研究中,应开展针对重金属吸附的生物炭原料特性及吸附产物的多维、微纳尺度表征方法研究。

Review of Biochar as Adsorbent for Aqueous Heavy Metal Removal

Biochar has a bright prospect due to its good surface properties, pore structure and broad raw materials of its production. It has already been a hotspot in the fields of environment, agriculture and energy. It can be produced from a variety of biomass feedstock, such as agricultural residues, manures, wood, bone and so on, under oxygen-limited conditions. It has great potentials for heavy metal remediation and waste water treatment due to its unique properties, low price, easy processing and wide range of preparation material. The existing literature was incorporated to understand the overall sorption research of heavy metals on biochar adsorbents. However, there was still lack of information on the roles of different sorption mechanisms for biochar. The effects of feedstock materials and pyrolysis temperature on biochar characteristics and metal adsorption capacity were discussed. The interaction mechanisms between biochar and heavy metals, such as ion exchange, complexation, physical sorption, precipitation and electrostatic interactions were analyzed in detail. The influence of adsorption conditions and heavy metal species on heavy metals adsorbed by biochar was also included. At the end, the future research directions on sorption of heavy metals by biochar were proposed. The review would help to build important theory and methodology foundation for directly controlling production and scientific utilization of biochar.