| POPs ( persistent organic pollutants, POPs) are one sort of organic compound with toxicity, permanence and which can easily accumulate largely in organism, transfer away and then become sediment; so POPs will make great damage to the people and environment nearby the headstream even far. POPs can circulate through the world by atmosphere, sea current and other ways; thus the pollution caused by them has been the worldwide environment problem.There few reports about the contamination status of PCBs in domestic soil; in addition, the investigated pollution area is quite finite, currently researching the Yangtze River Delta and Pearl River Delta. Because of area imbalance and difference of sampling-time, it is rather difficult to estimate the pollution status of PCBs in Chinese Soil; what's worse, PCBs are the most typical hard to disintegrate. Therefore, due to the long-term and vast use of PCBs in industry developed countries, solving the pollution of soil and bottom mud caused by PCBs is one of the most scabrous environmental problems to be confronted with. Consequently, this test samples soil countrywide to entirely find out the pollution status in internal soil, studies the transferring and fate rules of PCBs, as well as analyses the relationship of source and sink which is provided with great realistic significance. The research has a great deal with the decision-making to harness the PCBs contamination, also redounds to study environmental chemistry behavior of POPs from a higher view, hereby, offers important base to internal research of POPs.The main research includes following work: collecting 52 samples countrywide; treating the samples with air-dry, grinding, shifting out, removing impurity etc., then freezing reserve; establishing the methods of analyzing and dividing spectrums with 84 mixture standard samples separately on GC, GC-MS; through the comparison between microwave extraction and soxhlet extraction setting up the processing soil method; the preparation of silica gal pole and eluting-curve experiment, ascertaining the decontamination system; QA/QC, consisting of the analysis of sample vacancy and solvent vacancy, and confirming the detectability of test apparatus and method; determinating the moisture and organic materials in soil; detecting and analyzing PCBs in 52 samples; studying and analyzing the pollution status quo, space distribution and the pollution source of PCBs in Chinese topsoil.The test result indicates that though the whole PCBs pollution level is low in internal soil, there is evident difference in different areas, for instance, the pollution being serious in the soil of developed city. The basic feature is that the PCBs content in city soil is the most, rural soil the second and remote mountain area the least. The PCBs residual quantity in soil Kunming Yunnan is the most(1840 pg/g), that in Mingxing District taking second place(1730 pg/g).There is the most HexaCB in soil of Chinese cities, TriCB the second. However, most of the PCBs in the soil of country and remote area are TriCB and DiCB. Country and remote area have been the sink for atmosphere fate. The pollution status in these areas is concerned to pollution source area and the PCBs in air from the contaminated soil, and that exchanging between soil and air.Of the most residual quantity 10 kinds of PCBs, 6 kinds are TriCB and DiCB in the topsoil, and that of the most density 10 kinds of PCBs in Chinese transformer oil, 7 kinds are TriCB and DiCB. Among them, there are 5 kinds TriCB and DiCB(PCB18, PCB31/28, PCB5/8, PCB17, PCB22) are accordant. Moreover, the most density TriCB accounts for about 35% of the whole PCBs density in Chinese soil, which demonstrates that the main pollution source of soil PCBs comes from 1# PCBs in China. Nevertheless, Heavy PCBs is the first in the city soil, which may come from the auxiliary product of PentaCB or the transfer of PCBs in imported capacitors. The comparability between PCBs in soil and that in transformer oil make clear their relationship of source and sink.
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