【摘要】 生物炭的广阔应用前景吸引了研究者的广泛关注。生物炭中具有显著流动性的溶解性有机质(Biochar-derived dissolved organic matter,BDOM)作为一种高效的吸附载体,对污染物迁移的影响显著,是了解生物炭环境效应的关键。然而,原料来源及热解温度与BDOM的特性之间的关联性,以及BDOM与污染物相互作用的机制尚未明确。因此,文章通过综述原料及热解温度对BDOM特性的影响,以明确BDOM影响污染物环境行为机制的研究现状。有关研究表明:(1)生物质原料中木质素含量越高,BDOM C含量越高,官能团种类更加丰富,芳香性更强,而产率则越低;(2)随热解温度的升高,BDOM中C含量增加、芳香性增强,而产率及含氧官能团种类降低;(3)BDOM与疏水性有机污染物形成致密的类胶体结构,使疏水性有机污染物的溶解度提高,从而使疏水性有机污染物更容易被降解;(4)BDOM通过增加土壤中溶解性有机质的含量,从而形成新的吸附位点(如羧基官能团),以促进土壤对重金属或有机污染物的固持;(5)BDOM与重金属发生络合或氧化还原作用,影响重金属形态,从而改变土壤中重金属的毒性和生物有效性。该文可为全面评估生物炭在土壤污染修复应用中的功能提供参考。更多还原

【Abstract】 The prospect of the wide practical applications of biochar has attracted great attention.As an efficient absorbent carrier,biochar-derived dissolved organic matter(BDOM)is highly mobile and has key role in the immigration of pollutants,which is critical in the understanding of environmental impact of biochar.However,the relationship between substrates,pyrolysis temperature and the characteristics of BDOM,as well as the interactions of BDOM and pollutants,are still unclear.In this paper,current statue of the impact of BDOM on the environmental behavior of pollutants has been reviewed.It shows that(1)with the increase of lignin content in substrates,carbon content,species of the functional groups and aromaticity of BDOM increase,while the yield of BDOM decreases;(2)with the increase of pyrolysis temperature,carbon content and aromaticity of BDOM increase,while the yield and species of the functional groups of BDOM decrease;(3)BDOM combined with hydrophobic organic pollutants may form dense colloidal structure,which increase the solubility of organic pollutants and make them easier to be degraded;(4)BDOM may form new absorption sites(i.e.,carboxyl functional groups)through increasing dissoluble organic content in soil,which facilitates the fixation of heavy metals and organic pollutants;And(5)BDOM may affect species of heavy metals in complexation and redox reaction,which change toxicity and bioavailability of heavy metals in soil.This review may facilitate the overall assessment of the functions of biochar in the remediation of polluted soils.更多还原