深圳茅洲河表层沉积物卤代多环芳烃污染研究

Halogenated Polycyclic Aromatic Hydrocarbons in Surface Sediments of Maozhou River,Shenzhen

利用GC-MS方法分析了卤代多环芳烃(halogenated polycyclic aromatic hydrocarbons,HPAHs)在深圳茅洲河流域表层沉积物中的含量水平以及空间分布特征.所关注的3种氯代多环芳烃(chlorinated polycyclic aromatic hydrocarbons,ClPAHs)和6种溴代多环芳烃(brominated polycyclic aromatic hydrocarbons,BrPAHs)的含量范围分别是3.00～301 ng.g-1和7.52～285ng.g-1.表层沉积物中HPAHs的主要污染来源包括垃圾焚烧、化石燃料的燃烧、汽车尾气以及农作物秸秆焚烧,它们所占的比例分别是40%、20.5%、11.9%和11.7%.此外,表层沉积物中ClPAHs和BrPAHs的毒性当量(toxic equivalency quotients,TEQs)范围分别是7.95～38.1 pg.g-1和38.1～105 pg.g-1.研究发现,HPAHs的含量与采样点周边土地利用类型有关.随着工业用地密度的增大,表层沉积物中HPAHs的含量呈现出一个先增后减的趋势;而表层沉积物中HPAHs的含量与农业用地密度呈反比关系.

Surface sediments collected from the Maozhou River watershed in Shenzhen were analyzed for the concentration levels and spatial distribution characteristics of halogenated polycyclic aromatic hydrocarbons（HPAHs） using GC-MS.Total concentrations of three chlorinated polycyclic aromatic hydrocarbons（ClPAHs） and six brominated polycyclic aromatic hydrocarbons（BrPAHs） of concern ranged from 3.00 to 301 ng·g^-1 and 7.52 to 285 ng·g^-1,respectively.Source appointments indicated that the HPAHs in these surface sediments were mainly derived from waste incineration,fossil fuel combustion,vehicle emission,and burning of crop straw,accounting for 40%,20.5% 11.9%,and 11.7% of the total loading,respectively.Additionally,the toxic equivalency quotients（TEQ） of total ClPAHs and BrPAHs ranged from 7.95 to 38.1 pg·g^-1 and 38.1 to 105 pg·g^-1 respectively.Finally,the relationships between the HPAHs levels and different land use types were examined.Results indicated that the levels of HPAHs in surface sediments showed a decreasing trend after the first increase to the peak with the density of industrial land,but inversely proportional to the density of agricultural land.