燃油式火化机排放烟气中二□英类污染水平和排放特征

对国内6台燃油式火化机排放烟气中的二噁英类污染水平和排放特征进行了初步研究.结果表明:烟气样品中ρ(二噁英类)为9.2～120.0ng/m3273.15 K,101.325 kPa, φ(O2)为11%换算值],毒性当量(TEQ)浓度为1.0～8.1ng/m3;所有烟气样品中二噁英类同类物分布相似,17种2,3,7,8-氯代二噁英类同类物被全部检出,其中2,3,4,7,8-P5CDF对毒性当量浓度的贡献最大;ρ(PCDFs)高于ρ(PCDDs), ρ(T4CDFs)在PCDFs中最高;燃烧控制和烟气处理措施是影响燃油式火化机二噁英类生成和排放的重要因素.

Concentrations and Congener Profiles of PCDDs/PCDFs in Flue Gas Samples from Oil Type Crematories

Concentrations and congener profiles of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in flue gas samples emitted from six oil type crematories in China were studied. Total concentrations of PCDDs/PCDFs in these samples ranged from 9.2 to 120.0 ng/m~3 (273.15 K, 101.325 kPa, at 11% O_2), while their TEQ values were 1.0 to 8.1 ng/m~3 with similar congener profiles. The 17 types of 2,3,7,8-substituted isomers were detected in all flue gas samples, while 2,3,4,7,8-P_5CDF was the most important contributor to total TEQ concentration. The sum of PCDFs was higher than that of PCDDs, and the concentration of T_4CDFs was the highest among PCDFs. Combustion conditions and air pollution control measures were considered to be the dominant factors for PCDDs/PCDFs formation and emission from crematories.