【摘要】 利用燃煤耦合垃圾焚烧实验台和二噁英再合成实验台,研究了燃煤耦合垃圾焚烧烟气时二噁英浓度变化情况,重点探明了耦合焚烧后粉煤灰和灰渣再合成二噁英的质量浓度和同分异构体的分布情况。结果表明:与燃煤未耦合垃圾焚烧烟气产生的粉煤灰相比,燃煤耦合垃圾焚烧烟气后,煤粉炉烟气和灰渣中二噁英毒性当量降低;燃煤未耦合垃圾焚烧烟气产生的粉煤灰在350℃加热时,二噁英的质量分数由2.93 ng/g增加为3.86 ng/g,二噁英毒性当量由0.24 ng I-TEQ/g （International Toxic Equivalence Quantity）增加为0.49 ng I-TEQ/g,燃煤耦合垃圾焚烧烟气产生的灰渣在350℃加热时,二噁英的质量分数由1.64 ng/g增加为4.30 ng/g,而二噁英毒性当量却由0.63 ng I-TEQ/g降低为0.12 ng I-TEQ/g,这表明粉煤灰和灰渣加热后二噁英同分异构体分布变化趋势差异较大;在灰渣加热过程中通入41.2 mg/m³的HCl时,二噁英毒性当量变化较小,这表明灰渣和二噁英再合成过程中可能还缺少CuCl₂等金属催化剂;灰渣再合成的二噁英主要以PCDFs（polychlorinated dibenzofurans）为主,表明从头合成反应可能是二噁英生成的主要途径,同时低氯代PCDDs（polychlorinated dibenzo-p-dioxins）更容易被氯化生成高氯代PCDDs,因此二噁英毒性当量有所降低。更多还原

【Abstract】 The change in the dioxin mass concentration in the flue gas of the coal-fired coupled waste incineration was studied by using the experimental platforms of the coal-fired coupled waste incineration and the dioxin re-synthesis. The experiments were focused on the investigation of the mass concentration and isomer distribution of the fly ash and the ash re-synthesis after the coupled incineration. The results show that the toxic equivalent of the dioxin in the flue gas and ash of coal-fired boiler decrease after the coal-fired coupling waste incineration. The mass concentration of dioxin increase from 2.93 to 3.86 ng/g and the toxic equivalent of the dioxin increased from 0.24 ng I-TEQ/g（International Toxic Equivalence Quantity） to 0.49 ng I-TEQ/g when the coal-fired uncoupled waste incineration flue gas is heated at 350 ℃. When the ash generated from the flue gas of coal-fired coupled waste incineration is heated at 350 ℃, the mass concentration of dioxin increase from 1.64 ng/g to 4.3 ng/g, while the toxic equivalent of dioxin decrease from 0.63 ng I-TEQ/g to 0.12 ng I-TEQ/g, indicating that the distribution of dioxin isomers varied greatly after the thermal treatment of the fly ash and ash; In case that 41.2 mg/m³ HCl is introduced to the thermal treatment of the ash, the toxicity equivalent of the dioxin barely vary, indicating a lack of metal catalysts such as CuCl₂ during the process of the ash dioxin re-synthesis. The PCDFs（polychlorinated dibenzofurans） is the main mechanism of the dioxin re-synthesis, indicating that the ab initio synthesis may be the driving mechanism for the dioxin formation, and low-chlorinated PCDDs（polychlorinated dibenzo-p-dioxin） is more likely to be chlorinated to produce high-chlorinated PCDDs. To this end, the toxic equivalent of the dioxin is reduced.更多还原