城市生活垃圾与工业有机固废协同处置中有机污染物生成特征及控制技术

Generation characteristics and control technology of organic pollutants during the co-combustion of municipal solid waste and industrial organic solid waste

近年来固体废物产生量日益增多,而多种固体废物协同处置能够提高生活垃圾热值,实现固体废物的有效减容.为了有效减少有机污染物的排放,本文对在焚烧过程中二噁英、多氯联苯和多环芳烃的形成机理进行了探究,并着重阐明了不同固废(市政污泥与生活垃圾、木材与生活垃圾等)混烧产生有机污染物的排放特征以及关键影响因素.研究结果表明,固废种类、添加比例、组分、含水率等能够影响有机污染物的生成.较高的Cl和金属元素会促进有机污染物的生成,而S和N元素则有抑制效应.根据垃圾焚烧的工艺条件及有机污染物的生成机理,发现除“3T+E”外,改变固废性质、加入抑制剂及末端处置等方法也能有效控制有机污染物的产生.通过预处理可降低固废含水率提高热值.焚烧系统中可加入碱性化合物、硅铝复合添加剂、Mg(OH)_(2)、硫酸锰、铂和钯等抑制剂来减少PCDD/Fs、PCBs和PAHs等有机污染物的生成.末端控制主要包含吸附和催化分解,其中催化分解技术更加稳定、去除效率更高,但目前催化剂的低温活性还有待进一步提高.整体来看,在清洁生产的大背景下,拓展不同种类固体废物间的混烧,可达到节约能源、减少污染物排放等目的,但不同固废混烧过程中有机污染物生成特征变化及控制机理还需进一步深入研究.

In recent years,the amount of solid wastes generated has been increasing,and the cocombustion of multiple solid wastes can increase the calorific value of domestic wastes and achieve effective volume reduction of solid wastes.In order to effectively reduce the emission of organic pollutants,this paper explores the formation mechanism of polychlorinated dibenzo-p-dioxins and dibenzodurans(PCDD/Fs),polychlorinated biphenyl(PCBs)and polycyclic aromatic hydrocarbon(PAHs)during the incineration,and focuses on the emission characteristics and key influencing factors of organic pollutants during the co-combustion of solid wastes(municipal sludge and municipal solid wastes,woods and municipal solid wastes,etc.).The type of solid wastes,addition ratio,composition,moisture content,etc.can affect the generation of organic pollutants.Higher levels of Cl and metal elements promote the formation of organic pollutants,while S and N elements have an inhibitory effect.According to the process conditions of waste incineration and the formation mechanism of organic pollutants,it has been found that in addition to"3T+E",methods such as changing the nature of solid wastes,adding inhibitors and terminal control can also effectively control the generation of organic pollutants.The moisture content of solid wastes can be reduced and the heating value can be increased through pretreatment.Alkaline compounds,silicon-aluminum composite additives,Mg(OH)_(2),manganese sulfate,platinum and palladium and other inhibitors can be added in the incineration system to reduce the generation of organic pollutants,such as PCDD/Fs,PCBs and PAHs.The control technology mainly includes adsorption and catalytic decomposition.The catalytic decomposition technology is more stable and the removal efficiency is higher.However,the low temperature activity of the current catalyst needs to be further improved.Overall,under the background of cleaner production,expanding the co-combustion of different types of solid wastes can achieve the goals of saving energy and reducing emissions of pollutants.However,the formation characteristics and control mechanism of organic pollutants during the co-combustion needs to be further studied.