稳定化飞灰填埋处置环境中二噁英溶出影响因素研究综述

垃圾焚烧飞灰是一种富集二噁英类污染物的危险废物。随着我国垃圾填埋场从原生垃圾填埋向焚烧残渣(主要为稳定化飞灰)填埋转型,稳定化飞灰中的二噁英溶出将是未来填埋场渗滤液污染的重要来源之一,溶出过程受填埋环境中DOM(DOC、DHM、HA等)、pH值、表面活性剂、非有机溶剂和微生物作用等多种因素的共同影响。目前对填埋稳定化飞灰中二噁英的溶出风险问题尚缺乏全面认识。综述了国内外关于垃圾焚烧飞灰中二噁英的典型含量和分布特征,重点总结了稳定化飞灰填埋处置环境中影响二噁英溶出的主要因素及影响规律,分析了二噁英的溶出风险性。指出应从飞灰中二噁英产生的源头、过程以及最终处置等方面加强对二噁英的减量化,并开展关于共填埋处置环境或多因素交互影响条件下二噁英溶出和转化机制以及风险评估方法学的研究。

REVIEW ON INFLUENCING FACTORS OF DIOXIN LEACHED FROM STABILIZED FLY ASH IN LANDFILL ENVIRONMENT

Municipal solid waste incineration (MSWI) fly ash is a hazardous waste enriched with dioxins. With the transformation of MSW landfills from raw waste to incineration residues (mainly stabilized fly ash) in China, the leaching of dioxins from stabilized fly ash in landfill environments will be one of the key sources of landfill leachate pollution in the future. The leaching of dioxins in stabilized fly ash is affected by many factors such as DOM (DOC, DHM, HA, etc.), pH value, surfactants, non-organic solvents, and microbial action in the landfill environment. At present, there is a lack of comprehensive understanding of the risk of dioxins leaching from fly ash stabilized in landfills. This paper summarizes the typical content and distribution characteristics of dioxin in fly ash globally, focuses on the main factors and influencing laws affecting the leaching of dioxin in landfill stabilized fly ash, and analyzes the risk of dioxins leaching. It pointed out that the reduction of dioxins should be strengthened from the aspects of the source, process, and final disposal of dioxins in fly ash, and the research on the mechanism of dioxin leaching and transformation in co-landfill disposal environment or multi-factor interaction, and risk assessment methodology should be carried out.