生活垃圾焚烧厂烟气中二■英的分布及净化特征

Distribution characteristics of PCDD/Fs in flue gas from municipal solid waste incineration plant

以广州市某大型生活垃圾焚烧发电厂的3台焚烧炉(750 t·d^-1)为对象,研究了焚烧烟气净化前后二噁英类同系物的分布特征及其污染控制效果.结果表明,采用“半干法脱酸+活性炭+布袋除尘”烟气净化工艺对二噁英的去除率能达到97.3%—99.4%.焚烧烟气中二噁英类同系物的分布特征表明,生活垃圾焚烧发电过程中二噁英主要在烟气换热过程合成.烟气净化过程中,活性炭喷射+布袋除尘净化系统对二噁英类同系物的去除效率存在一个优先级关系,即PCDDs〉PCDFs且高氯代PCDFs〉低氯代PCDFs.净化后的烟气中二噁英类同系物2,3,4,7,8-PeCDF的质量浓度与对应的二噁英当量浓度的相关性最高,相关系数R 2为0.959,可以考虑将2,3,4,7,8-PeCDF作为二噁英的快速应急检测的指示物.

Based on the date from three incinerators(750 t·d^-1)of a municipal solid waste incineration plant in Guangzhou,the distribution characteristics and pollution control effects of PCDD/Fs were investigated before and after incineration purification.The results revealed that the semi-dry deacidification+activated carbon+bag filter technology could effectively remove 97.3%—99.4%of dioxin in the flue gas.The distribution features of PCDD/Fs in the flue gas before purification indicated that dioxins were mainly synthesized in flue gas heat transfer process.The flue gas purification process possessed the following pattern of the removal efficiency of PCDD/Fs:PCDDs>PCDFs and high-chlorinated PCDFs>Low-chlorinated PCDFs.The mass concentrations of 2,3,4,7 and 8-PeCDF in purified flue gas showed the highest coefficient of determination(R 2=0.959)with dioxin-equivalent concentrations.Therefore,2,3,4,7 and 8-PeCDF appeared to be a rapid indicator of the emergency detection of dioxins.