火化机中二英的排放特征和指示物的研究

Emission characteristics of PCDD/Fs from crematories and identification of I-TEQ indicator in flue gases

综合分析了所测的遗体火化炉的36个样品和文献中41组数据中二英(PCDD/Fs)化合物的排放指纹特征,分析了不同单体与毒性当量浓度I-TEQ的相关性,提出了适合火化炉的I-TEQ指示物,为以后实现在线监测PCDD/Fs提供依据.结果表明,本次监测样品的毒性当量浓度跨度较大,为0.014~24.0 ng·m^(-3)(以I-TEQ计,下同),平均值为2.68 ng·m^(-3).所有新建火化炉的结果均低于0.5 ng·m^(-3),75%的旧炉超过2017年7月1日开始执行的新标准限值,表明现有部分老旧火化炉及其尾气处理设施亟需技术改造才能满足新要求.体积分数最高的单体依次为OCDD、1,2,3,4,6,7,8-Hp CDF和1,2,3,4,6,7,8-Hp CDD,分别为16.7%±11.8%、12.1%±4.4%和11.9%±4.2%.对I-TEQ的贡献率最大的单体为2,3,4,7,8-Pe CDF,且PCDFs与PCDDs的毒性当量浓度比值,即ρ(PCDFs/PCDDs)>1.四、五、六氯代二英和呋喃与I-TEQ具有显著的线性相关性,其中,1,2,3,7,8-Pe CDF、2,3,4,7,8-Pe CDF和1,2,3,7,8-Pe CDD与I-TEQ的相关系数r大于0.89.与I-TEQ线性关系最佳的单体为2,3,4,7,8-Pe CDF,R^2为0.97,斜率为2.36;最佳的同类物为Pe CDF,R^2为0.97,斜率为2.22.

The study analyzed the fingerprint characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs）of the 36 samples emitted from flue gas and that of the 41 date groups in literature.The correlations between PCDD/Fs monomers and I-TEQ were analyzed and the suitable I-TEQ indicator was proposed,which are the potential support for the online monitoring of PCDD/Fs in future.It was found that the emissions levels of PCDD/Fs ranged from 0.014 to 24.0 ng·m^-3,with the average of 2.68 ng·m^-3.The emission levels of newly-built crematories were all below 0.5 ng·m^-3,while75%of the old crematories＇results exceeding the new standard＇s limitation which would be implemented on July 1,2017.It was indicated that a part of the old crematories and their flue gas treatment plants needed to have technical reconstruction to meet the new standard.The monomers that contributed to the PCDD/Fs concentrations most were OCDD,1,2,3,4,6,7,8-Hp CDF and 1,2,3,4,6,7,8-Hp CDD,accounting for 16.7%±11.8%,12.1%±4.4%and 11.9%±4.2%,respectively.2,3,4,7,8-Pe CDF contributed to the largest I-TEQ level,with theρlevel（PCDFs/PCDDs）larger than 1.There were good correlation relationship between Tri-,Pe-,Hx-PCDD/Fs and I-TEQ.The correlation coefficients between 1,2,3,7,8-Pe CDF,2,3,4,7,8-Pe CDF,1,2,3,7,8-Pe CDD and I-TEQ were greater than 0.89.The monomer 2,3,4,7,8-Pe CDF and the congener Pe CDF had the best correlation coefficient with I-TEQ.Their correlation coefficient values were both 0.97,and the slope values were 2.36 and 2.22,respectively.