污泥处置过程中主要有机污染物生成及迁移转化规律

多环芳烃(PAHs)、多氯联苯(PCBs)等有机污染物广泛存在于各种污泥中.污泥主要有填埋、堆肥、焚烧和热解等处置方法,各种处置方法在无害化处理、资源化、能源化利用方面各有侧重,而有机污染物的消除是污泥无害化处理的重要内容,也是污泥资源化、能源化利用的基础.从污泥不同处置技术入手,系统总结了现有的处置技术中各主要有机污染物生成、迁移及转化规律.生物降解作用是填埋和堆肥技术中有机污染物减少的主要因素.焚烧过程中二噁英的产生量与温度、氧含量、氯含量、颗粒物表面的金属离子等因素密切相关,污泥热解过程中PAHs的生成机理为狄尔斯-阿尔德反应机理,加热温度、加热方式和添加剂均会影响热解油中PAHs含量,在此基础上指出了污泥处置技术的研究热点在于优化处置过程的控制参数,达到有效减少和抑制有机污染物的生成的目的,进而实现污泥资源化和能源化利用.

Main organic pollutants formation mechanism and migration and transformation laws in sewage sludge disposal process

Organic pollutants such as polycyclic aromatic hydrocarbons(PAHs) and polychlorinated biphenyls(PCBs) are widely existed in various kinds of sludge.Landfill,composting,incineration and pyrolysis are dominating sludge disposal options;these various disposal options have different advantages such as free-pollution disposal,resources utilization and energy-oriented use.This paper illustrated briefly the changes of organic pollutants in the disposal process.For landfill and composting,biodegradation was the primary factor contributing to the organic pollutants reduction.For incineration,temperature,oxygen content,chlorine content and the metal ions in particles surface influenced mainly on the amount of dioxin.The paper also probed the formation mechanism of PAHs in sludge pyrolysis process,indicated heating temperatures,heating methods and additives influenced PAHs content in the pyrolytic tar.