【摘要】 人类活动产生的重金属与农药残留的有机污染物在土壤中的积累致使土壤遭受严重污染,引发了一系列生态问题。生物炭及其复合材料因其独特的表面结构使其可通过物理或化学等作用吸附土壤中的污染物,限制其在生态系统中的迁移与传递过程,进而改善土壤理化性质,因此生物炭在土壤污染治理方面的应用研究越来越多地引起关注,但多数研究局限于实验室水平。文章对近年来生物炭及其复合材料在自然土壤环境中的应用的相关研究进行了整理,从重金属与有机污染物两个方面切入,阐述了不同生物炭材料在污染土壤中对两类污染物的作用机理;介绍了生物炭的改性和复合方法及其应用优势,同时对生物炭材料在污染土壤修复中的研究重点进行了展望。复合材料可以显著增强生物炭对污染物的吸附性能。从吸附机理上看,生物炭及其复合材料对重金属污染多以静电作用、离子交换作用、表面官能团作用为主;对有机污染物则主要以分配作用、吸附作用、孔隙填充为主,但在实际应用过程中,这些机理往往共同发挥作用,只是贡献程度不同。另外,生物炭及其复合材料也可通过提高土壤质量间接增强土壤对污染物的抗性等。虽然纳米材料能够增强生物炭的性能,但其对土壤中微生物的毒性机理尚不完全清楚。综上所述,生物炭及其复合材料在自然土壤环境中的应用能显著降低污染物的毒性,但新型生物炭复合材料的作用机理有待进一步的研究和论证。更多还原

【Abstract】 Soil accumulation of heavy metals from human activities and organic pollutants from pesticide residues causes serious pollution in terrestrial ecosystem. The unique structure provides biochar and its composite an ability to adsorb the toxic pollutants by physiochemical interaction, immobilize and limit the migration and transportation of pollutants in soil, leading to the improvement of soil physiochemical properties. Therefore, the application of biochar and its composite for soil remediation has received worldwide attention. However, most of the studies are still limited in the laboratory. This study summarizes the researches on biochar and its composite application for remediation of soil polluted by heavy metals and organic pollutants and illustrate the mechanisms for removal and interaction of heavy metals and organic pollutants. The study also reports and discusses the methods for biochar modification, the advantages and perspectives of biochar composite for remediation of contaminated soil. The application of these composite can significantly enhance the adsorption property. The mechanisms for heavy metal remediation mainly include electrostatic interaction, ion exchange and surface function group interaction. For organic pollutants, the mechanisms are distributional effects, sorption and pore filling. In reality, these processes and mechanisms may occur together and contribute variously to soil remediation. Furthermore, biochar and its composite can also strengthen soil resistance to pollutants by improving soil quality. Although nanomaterials can raise biochar property but its toxicity to soil is still unclear. Overall, the application of biochar and its composite can drastically mitigate the toxicity of pollutants, but new type of biochar composite application still needs more test within the terrestrial ecosystem.更多还原