多环芳烃和二恶英是两类剧毒的持久性有机污染物,为了研究其生成和排放过程,需要开发一种能用于烟气的实时检测方法。该文采用高分辨力的真空紫外光电离/微型正交加速型电离飞行时间质谱仪(VUV-TOF-MS),对由聚氯乙烯(PVC)在氮气流中热解形成的模拟烟气中多环芳烃和二恶英的前驱物进行了实时在线检测。然后和离线方法的分析结果进行对比,给出了烟气中多环芳烃和二恶英前驱物的实时浓度曲线。再根据三氯苯和二恶英的转化率,估算出二恶英的在线浓度范围。同时根据对烟气中多环芳烃和二恶英前驱物的时间行为特征的研究,讨论了PVC热解时多环芳烃和二恶英前驱物的发生机理和成长途径。
Polycyclic aromatic hydrocarbons(PAHs), polych-lorinated dibenzyl-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are known to very toxic persist organic pollutants(POPs). For improving the knowledge about the PAHs and PCDD/Fs forming and emitting process, time-resolved flue-gas analysis has to be performed. High- performance time-of-flight mass spectrometry (TOF-MS) combined with vacuum ultraviolet photo-ionization was applied to on-line real-time measurements of PAHs and PCDD/Fs precursor in the simulated flue gas, and off-line analysis experiment has been finished to substance qualitative determination. The real-time emission profiles of PAHs and PCDD/Fs precursor was acquired, and that according to the PCDD/Fs forming rate from trichlorobenzene, the on-line PCDD/Fs concentratiOn range was estimated. In addition, the time-resolved behavior characteristic of PAHs and trichlorobenzene in the simulated flue gas was employed to explained the PAHs and PCDD/Fs precursor formation mechanism and growth route.