烟气中二恶英的光降解实验研究

光降解是环境大气中二恶英的主要降解途径，该文在管式炉和光降解装置中研究了五氯酚焚烧烟气中二恶英的光降解和光臭氧氧化降解过程，利用高分辨色谱/低分辨质谱测定了气态中的二恶英。试验结果表明：五氯酚燃烧生成的烟气中二恶英的光解途径主要以脱氯为主，八氯代二恶英及七氯代二恶英分子结构上的氯脱落降解成低氯代的二恶英。紫外光/臭氧氧化技术对气态中的二恶英降解主要是由于产生的羟基自由基与二恶英发生亲电加成反应的结果。在该文的试验条件下，紫外/微臭氧氧化技术即可达到对二恶英有效的降解，二恶英总量和毒性当量的降解率在69%左右。

Experimental Study of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans Photodegradation in the Flue gas

Photodegradation of polychlorinated dibenzo-p- dioxins and dibenzofurans (PCDD/Fs) in the atmosphere is an important environmental transformation. The photodegradation and ultraviolet/ozone oxidation process of PCDD/Fs produced from pentachlorophenol (PCP) combustion were studied in a tubular oven. The PCDD/Fs concentrations in the gas phase were detected by high resolution gas chromatograph/low resolution mass spectrometer (HRGC/LRMS). The experimental results show that, the major photodegradation route of PCDD/Fs produced from PCP combustion is dechlorination. Chlorines of octachlorianted dibenzo-p-dioxin (OCDD) and heptach- lorrinated dibenzo-p-dioxin (HpCDD) are broken off and then degraded to lower-chlorinaed dibenzo-p-dioxins(PCDDs). PCDD/Fs are degraded by the electrophilic addition between OH radical, which produced from ultraviolet/ozone oxidation, and PCDD/Fs. Ultraviolet/micro-ozone oxidation technology can decompose PCDD/Fs effectively and result in about 69% reduction of PCDD/Fs concentration and international-toxic equivalent quantity (I-TEQ).