某典型电子垃圾拆解区大气中氯化石蜡和多氯联苯的污染特征

The migration pollution characteristics of chlorinated paraffin and polychlorinated biphenyls in the disassembly area of electronic waste

以广东某镇典型电子垃圾拆解区电子垃圾焚烧样品中大气样品为研究对象,利用多层硅胶柱进行前处理,采用气质联用法检测了气相和颗粒物中的氯化石蜡(CPs)和多氯联苯(PCBs)。结果表明,大气迁移过程中ΣCPs(4种SCCPs同分异构体和24种MCCPs同分异构体)在气相中的浓度(6.90~306.8 ng/m^3)高于颗粒相(2.1~63.6 ng/m^3)。ΣPCBs(7种指示性PCBs,CB-28,52,101,118,153,138,180)在气相中的浓度(5.5~95.3 ng/m^3)高于颗粒相(2.1~43.7 ng/m^3)。污染物浓度冬季高于夏季,污染物浓度与焚烧地点距离呈现指数下降趋势,将CPs和PCBs在TSP和气相中的浓度进行自然对数线性拟合CPs衰解斜率分别为-0.4981和-0.6142,比PCBs衰解斜率-0.4621和-0.4621绝对值大,说明CPs的浓度迁移降解速度比PCBs快。随着迁移距离变远,低氯取代相对百分含量呈现升高的趋势,高氯取代相对百分含量呈现降低的趋势。

Atmospheric samples from electronic waste incineration samples in a typical e-waste dismantling area in a town of Guangdong Province were used as research objects in this study. The multi-layer silica gel column was used for pretreatment, and the chlorinated paraffins （CPs） and Polychlorinated biphenyls （PCBs） in the gas phase and particulate matter were detected by gas chromatography-mass spectrometry. The results showed that the concentration of CPs （24 SCCPs isomers and 24 MCCPs isomers） in the gas phase during atmospheric migration was higher in the gas phase （6.90 -306.8 ng/ms） than in the particulate phase （2.1 -63.6 ng/mS）. PCBs （7 indicator PCBs,CB- 28,52,101,118,153,138 and 180） have a higher concentration in the gas phase （5.5-95.3 ng/ms） than the particle phase （2.1-43.7 ng/mS）. The concentration of pollutants in winter is higher than that in summer, and the concentration of pollutants and the location of incineration shows an exponential decline. The natural log-linear fitting of CPs and PCBs in the TSP and gas phase is -0.498 1 and -0.614 2, respectively. It is larger than the absolute slope of PCBs -0.462 1 and -0.4621, indicating that the concentration of CPs migrates faster than PCBs.As the migration distance becomes longer, the relative percentage of low chlorine substitutions tends to increase, and the relative percentage of high chlorine substitutions tends to decrease.