Homologues Levels and Distribution Pattern of Polychlorinated Biphenyls in Typical Capacitor Contaminated Soil

The homologues levels, distribution characteristics and TEQ of 209 PCBs in soil collected around 3 storage sites of PCB-containing wastes were investigated. The PCBs contents and environmental risk were evaluated to provide a scientific basis for site remediation of PCBs contaminated soil. Totally 12 soil samples were collected from 3 PCB-contaminated sites. The analysis results showed that the PCB-concentration in Soil A was 1 705. 0 µg.g-1 ± 424. 3 µg.g-1 (n =4), higher than Soil B (233. 0 µg.g-1 ± 80. 0, n = 4) and Soil C (225. 7 µg.g-1 ± 90. 2 µg.g-1, n = 4), indicating the soil was heavily polluted by PCBs. Trichlorobiphenyl and Tetrachlorobiphenyl dominated the homologues of PCBs. The mass fraction of chlorine in Soil A, Soil B and Soil C was 43. 7% 1. 0%, 45.5% ± 0. 5% and 44.9% ± 0.3%, respectively, which was similar as Aroclor1242 and l#PCB insulating oil. There was an obvious linear correlation between indicator PCBs and total PCBs (R2 = 0. 998), so indicator PCBs can be used to estimate the level of total PCBs. PCB77, PCB105, PCB118 were predominant in doxin-like PCBs, accounting for 89. 5% ± 4. 0% in total. The TEQ levels of the soil samples (in WHO-TEQ) were 3. 56-63. 55 ng.g-1, which demonstrated a high environmental risk in the area. PCB28/31, PCB33/20, PCB66/80, PCB70, PCB32 and PCB18 were the main PCBs isomers. Compared with other results, the local soil was heavily contaminated by PCBs and the surroundings were under a relatively high risk of environmental contamination.