生活垃圾焚烧飞灰水洗过程中理化特性及二噁英分布规律研究  

Investigation on Physicochemical Properties and PCDD/Fs Distribution Patterns of MSWI Fly Ash During Water Washing Process

作　　者：龙吉生 姚挺 LONG Jisheng;YAO Ting(Shanghai SUS Environment Co.Ltd.,Shanghai 201703)

机构地区：[1]上海康恒环境股份有限公司,上海201703

出　　处：《环境卫生工程》2022年第3期41-45,共5页Environmental Sanitation Engineering

基　　金：国家重点研发计划项目(2020YFC1910100)。

摘　　要：采用三级水洗,分析水洗前后生活垃圾焚烧飞灰和洗灰废水的物理化学性质及二噁英形态、含量,探明了水洗预处理过程中飞灰二噁英的迁移、分布规律。结果表明:Cl、Na、K等可溶性成分,水洗去除效率达90%以上,主要沉积在飞灰中小颗粒表面,导致水洗后飞灰粒径中位值减小。Ca、Mg则主要以低溶解性化合物残留在水洗飞灰中。水洗后二噁英毒性当量出现了富集,二噁英毒性当量(TEQ)从水洗前的166 ng/kg增加至水洗后的232 ng/kg。飞灰中17种二噁英同系物的毒性当量分布规律并未发生明显变化。洗灰废水中毒性当量最高的为2,3,7,8-TCDD,占洗灰废水总毒性当量的33.93%,从原灰向洗灰废水的迁移率仅为0.26%。Three-step water washing was applied to analyze the physical and chemical properties,forms and contents of PCDD/Fs of municipal solid waste incineration(MSWI)fly ash and washing effluent before and after washing.The migration and distribution patterns of PCDD/Fs in fly ash during water washing pretreatment were proved.The results showed that washing removal efficiency of soluble components such as Cl,Na and K were more than 90%,mainly deposited on the surface of small and medium particles of fly ash,resulted in a decrease of the median particle size of fly ash after washing.While Ca and Mg mainly remained in the washed fly ash in the form of low-solubility compounds.The enrichment of toxic equivalent(TEQ)of dioxins in washed fly ash was indicated by an increase from 166 to 232 ng/kg after water washing.The TEQ distribution patterns of 17 PCDD/Fs congeners in fly ash did not change significantly.The highest TEQ of the washing effluent was 2,3,7,8-TCDD,accounted for 33.93% of the total TEQ of the washing effluent.And the migration ratio of 2,3,7,8-TCDD from raw fly ash to washing effluent only reached 0.26%.

关 键 词：生活垃圾焚烧飞灰 水洗 二噁英 

分 类 号：X799.3[环境科学与工程—环境工程]