典型钢铁厂周边土壤中多氯联苯分布特征研究

钢铁厂中各工业热过程车间都会产生污染物并对周边环境造成危害,本文以迁安市钢铁厂周边土壤为研究对象,对该市内及钢铁厂周边土壤样品进行采集,采用同位素稀释高分辨气相色谱-高分辨质谱方法(HRGC/HRMS)测定了多氯联苯(PCBs)的含量,研究了PCBs的同类物分布特征.结果发现,市内及钢铁厂周边土壤样品中dl-PCBs的总含量为4.77~462.04 pg·g~(-1),WHO-TEQ(Toxic Equivalent Quantity)即毒性当量值为0.03~1.34 pg·g~(-1).由此可以看出,该市及钢铁厂周边环境土壤受到了PCBs等有毒污染物的影响.大部分土壤样品的同类物分布特征相似;PCB~(-1)18对土壤dl-PCBs含量贡献率最大,贡献率为34%.PCB~(-1)01对土壤指示性PCBs含量贡献率最大,贡献率为42.5%.同时,通过对样品中同类物分布可以看出,低氯代的同类物(Tr CBs~Hx CBs)的含量要远高于高氯代同类物(Hp CBs~De CBs).

Concentrations and profiles of PCBs in the surrounding soil of a typical steel plant

Industrial thermal processes in typical steel plants can produce pollutants that are detrimental to the surrounding environment. The concentrations and distributions of polychlorinated biphenyls (PCBs) in surface soil in the city of Qian''an, China were determined by analyzing soil samples using an isotope-dilution high resolution gas chromatography-high resolution mass spectrometry method. The total dioxin-like PCB concentrations in the samples were 4.77~462.04 pg·g^-1, and the toxic equivalent concentrations (calculated using World Health Organization toxic equivalence factors) were 0.03~1.34 pg·g^-1. We concluded that soil in Qian''an was contaminated with PCBs. The PCB homolog patterns in most of the soil samples were similar. PCB-118 was the main contributor to the total dioxin-like PCB concentrations, contributing 34%. PCB-101 was the main contributor to the total indicator PCB concentrations, contributing 42.5%. The less chlorinated PCB congeners (trichlorobiphenyls to hexachlorobiphenyls) were found at much higher concentrations than the more chlorinated congeners (heptachlorobiphenyls to decachlorobiphenyl).