By sampling dioxins discharged from typical biomass combustion boilers (including large-, medium-, and small-scale) in southern region and undergoing sample pretreatment, the dioxin samples were analyzed by high-resolution gas chromatography/high-resolution mass spectrum (HRGC/HRMS). Data showed that the total average concentration of dioxin discharged by large-scale biomass combustion boiler was 40.8pg/m3, consisting of 4.85~20.6pg/m3 in particles and 21.3~45.2pg/m3 in gas phase, each of which was much lower than the discharge concentration from the medium-scale biomass combustion boiler, which was 2470pg/m3 in total average, 34.3~4074pg/m3in particles, and 99.6~3261pg/m3 in gas phase, respectively. Furthermore, the small-scale biomass combustion boiler had the highest dioxin discharge concentration, with 16234pg/m3 in total average, 441~43170pg/m3 in particles, and 776~5553pg/m3 in gas phase, respectively. The distribution characteristics of dioxin homologues in the flue gas of the biomass combustion boiler showed that HpCDF and OCDD constituted the major contribution to particle and gas phase dioxins in large-scale enterprise, with each percentage of 16.0%~44.7% and 14.0%~62.9%, respectively. However, HxCDF, HpCDF and PeCDF, HxCDF were the major contributor to the particle and gas phase dioxin concentration, the percentage reached to 10.0%~29.3%, 8.0%~20.9% and 12.4%~44.0%, 17.0%~31.4%. The I-TEQ distribution of dioxin in the biomass combustion boiler shows that the I-TEQ content of PCDFs was greater than that of PCDDs, where 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD were the major contributors to I-TEQ in dioxin of both particles and gas phase. Besides these two components, 2,3,7,8-TCDD was the third major contributor to I-TEQ in dioxin of gas phase. There was a significant linear relationship between the concentration of 2,3,4,7,8-PeCDF and the total concentration of dioxin (including the particle phase and the gas phase dioxin), withR2 of 0.999, 0.981 and 0.991, respectively, provided indicating information on the study of dioxin.%选取南方典型生物质燃烧锅炉,采集大型、中型和小型生物质燃烧锅炉排放的二噁英,进行样品前处理和高分辨气相/高分辨质谱分析,结果显示:大型生物质燃烧锅炉企业排放的二噁英颗粒相和气相浓度范围为4.85~20.6pg/m3和21.3~45.2pg/m3,总浓度均值为40.8pg/m3,低于中型企业排放的颗粒相和气相二噁英浓度34.3~3976pg/m3和99.6~3261pg/m3,总浓度均值2470pg/m3,小型生物质燃烧锅炉排放的二噁英浓度最高,颗粒相和气相二噁英的浓度范围为441~43081pg/m3和545~5553pg/m3,总浓度均值为16234pg/m3.生物质燃耗锅炉排放烟气中气相和颗粒相的二噁英同系物分布特征显示.大型企业颗粒相和气相中贡献率高的单体均为HpCDF和OCDD.其贡献率分别为:16.0%~44.7%和14.0~62.9%.中型和小型企业颗粒相和气相贡献率较大的单体为HxCDF、HpCDF和PeCDF、HxCDF,其贡献率分别为:10.0%~29.3%、8.0%~20.9%和12.4%~44.0%、17.0%~31.4%.生物质燃烧锅炉排放的二噁英I-TEQ分布特征显示PCDFs的I-TEQ量要大于PCDDs,二噁英颗粒相中I-TEQ贡献率较大为2,3,4,7,8-PeCDF和1,2,3,7,8-PeCDD,气相则还包括了贡献率较大的2,3,7,8-TCDD.2,3,4,7,8-PeCDF与二噁英的颗粒相、气相和总浓度之间存在显著线性关系,R2分别达到了0.999、0.980和0.991,可作为二噁英研究的指示物.
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