The Particle-Scale Distribution Of PAHs And Organochlorine Pesticides (OCPs) In Contaminated Sediments Of Pearl River (Guangzhou Channel)

In this work, wet sieving was performed to separate the sediment into five size fractions( >500 m,500 m> >>220 m,220 m> >63 m,63 m> >220 m, 22 m)and further separated into low(<1.8g/cm3) and high(>1.8g/cm3) density fractions using a cesium chloride solution having a specify gravity of 1.8 + 0.05. These fractional particles were be analyzed by microscope. Each of these size and density separated fractions were then analyzed for PAHs and OCPs.The result of this work indicated that:1. In Bai' e' tan sample, the mass of organic sorbents in sample were 9.1% of total sediment mass ,but contain 81.5% PAHs and 77.2%OCPs Inorganic sorbents and Amorphous OM contain which reprent 90.9% total sediment mass 18.5% PAHs and 22.8% OCPs.2. In Huangpu sample, the mass of organic sorbents of sample were 8.95%of total sediment mass ,but 56.5% PAHs and 30.5%OCPs were been contained, Inorganic sorbents and Amorphous OM contained 43.5% PAHs and 69.5% OCPs which reprent 91.05% total sediment mass total sediment mass .3. The concentration of of PAHs in organic sorbents are 1-2 orders ofmagnitude higher than inorganic sorbents and amorphous OM inGuangzhou channel sediment. 4. carbon soot and coke have high capacity of sorption of PAHs , OtherwiseVegetal debris have low capacity of sorption of PAHs. Our results showed that the study of different size and structure sediment and their effect on distribution of PAHs and organochlorine pesticides in high contaminated sediments will benefit us to understand the transformation and fate of POPs and provide a scientific basis and valuable references on establish of the environmental quality standards and remediation of POPs .