Bioavailability Of Dioxin-like PCBs In The Soil Of Typical Industrial Zone In Jinan City

Dioxin-like PCB is a typical class of persistent organic pollutants (POPs), which persistent in the environment, accumulate in the food chain. It may impact to humans, higher organisms, even the substance which exposure to it in a way.It is potentially harmful for the the environment and human. The industrial zone in the eastern part of the Jinan, Iron and Steel, oil refineries, fertilizer plants are likely to be the class of the source of emissions of dioxin-like PCBs. Distribution characteristics and bioavailability of Jinan Industrial Zone, dioxin-like PCBs, can provide a scientific basis for the evaluation and prediction of PCBs industrial areas of biological and environmental impact.The Postdoctoral Science Foundation project "The research of environmental biological availability forecasting model of typical PCBs in soil "are fouded for this study.Based on the investigation of PCBs pollution sources in jinan industrial zone, using Soxhlet extraction-GC-ECD double column of complementary technologies to detect the12most toxic dioxin-like PCB contamination status and distribution characteristics; mild reagent beta-cyclodextrin (HPCD) extraction-double-column GC-ECD complementary to detect soil dioxin-like PCBs in biological concentration, to evaluate the bioavailability of PCBs in the soil, soil characteristics parameters of PCBs biological effectiveness, the main conclusions following:(1)The investigation of dioxin-like polychlorinated biphenyls sourcesJinan Iron and Steel Industrial Zone PCBs homologues more lower chlorinated PCBs, which the maximum tetrachloro biphenyl contribution rate is relatively high frequency of occurrence. PCBs PCBs products mainly from the the chloride oxidation processes (such as lubricants, transformer oil, heat exchange, etc.), the incinerator combustion and process. The chlor-alkali of the steel mills, coking, iron making, steel-making process used in conducting oil, hydraulic oil, vacuum pumps, electrical switches, regulators, the liquid insulated cables, power capacitors contain or release of PCBs, oil refineries pollution sources of PCBs leaked from the production of byproducts.(2)The distribution of12kinds of dioxin-like PCBs pollution in Jinan Industrial Zone, Status and Features:Soxhlet extraction-GC-ECD-Post complementary detected in soil12most toxic dioxin-like PCB contamination status and distribution characteristics of the results:the total concentration of dioxin-like PCBs in the soil1.95-215.94ng/g, an average of64.10ng/g PCBs peak in this industrial area near the refinery, the concentration of PCBs declining trend with the increase in distance from the industrial zone was the results also show that the PCBs contaminated areas main source of PCBs in its neighboring regions contributed greatly to the outer suburbs far from industrial areas, the presence of PCBs in the soil may be related to other forms of indirect input. Four or five chlorine substitution in the industrial zone soil dioxin-like PCBs accounted for the majority.12species measured dioxin-like PCB toxicity equivalent the greatest contribution the PCB126, followed by PCB169, the two PCBs homologues toxicity contribution rate has reached more than90percent.(3)The study of PCBs bioavailabilityDirect biological monitoring method and earthworms closest gentle extraction method for the determination of beta-cyclodextrin Jinan City Industrial Zone soil dioxin-like PCBs bioavailable concentration of bioavailable concentration and the concentration of PCBs in the soil reasons for the differences, the study of soil in12PCBs bioavailability of dioxin-like PCBs draw conclusions measured octanol-water coefficient, with the increase in the number of chlorine atoms, polychlorinated biphenyls logKow also with increased bioavailability of PCBs increased with increasing chlorine atoms.(4)Soil characteristic parameters of the dioxin-like PCBs b bioavailabilityOn ignition method were used respectively to measure soil organic matter content and use of the acidity in the soil PH measurement, use SPASS software analysis of soil parameter’s influence on the type of dioxin-like PCBs biological effectiveness obtained10sampling points in the soil, the biological effectiveness and organic matter in the soil of PCBs is a negative correlation, and the the PH of soil had a little effects on the biological effectiveness of PCBs in the soil.