Distribute Characteristics, Transfer And Ecological Risk In Multimedia Environment Of Polybrominated Diphenyl Ethers In Electrical Equipment Dismantling Area

Polybrominated diphenyl ethers (PBDEs) was widely used as fire retardant added in the textiles,polyurethane foam,electronic components,equipment andplastics. Because PBDEs have potential carcinogenic effects and toxic effects on thenervous,endocrineand immune system, they are regarded as new environmental organic pollutants.The distribution characteristics and ecological risk of the PBDEs in sediments from a typical waste electrical dismantlingarea were analyzed.The chemical behavior trend of polybrominated diphenyl ethers in the environment was simulatied through the multimedia fugacity modelin this paper.The conclusions are as follows:(1) The results showed that concentrations of PBDEs were ranged from 101 to 20400 ng/g with an average of 3700 ng/g, and BDE209 was the most dominant homologue accounted for more than 94% in all detected homologues. The concentration of PBDEs washigher in the middle of river than that in upstream and downstream and the average concentration in downstream was higher than the upstream,with a peak of concentrationin the area near by dismantling industrial park.PBDEs pollution in this region is relatively serious compared with other regions.(2)It was estimated that 0.39t PBDEs (including 0.36t BDE209) was discharged into the river as a result of dismantling industrial activities in last 40 years. A preliminary ecological risk assessment for PBDEs in sediments was conducted by Hazard quotient method, the results showed that the OctaBDEs and DecaBDEs were in a low ecological risk, while the PentaBDEs was in a particularly high risk andcould cause great harm to the environment.(3) A multimedia fugacity model was applied to simulate the distribution, transfer and fate of typical polybrominated diphenyl ethers (BDE47, BDE99, BDE209) in air, water, soil and sediment inanelectrical equipment dismantlingarea.The concentrations from the model were compared with monitoring data in air, soil and sediment for validation purpose. Moreover, the transfer fluxes between different compartments were analyzed in order to infer the main transfer process. Taking BDE47and BDE209as samples, parameters of the model were tested and the key parameters were identified using sensitivity analysis method.The results showedthat when the system reaches equilibrium, most of the PBDEs accumulated in soil and sediment. The air advection outflow and soil degradation were themajor routes for PBDEs to disappear in the area. The results of sensitivity analysis indicated that vapor pressure ? the logKow value and half-life had significant influence on concentrations of PBDEs in different media.