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| Distribution characteristics and risk evaluation of organoclorine pesticides in runoff from typical area of Danjiangkou Reservoir |
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Abstract Five groups of artificial runoff fields were built to collect runoff based on the different types of land-use in the Middle Line Source Area of South-to-North Water Diversion Project area around Danjiangkou Reservoir. The distribution characteristics of organ chlorine pesticides (OCPs) in runoff of aqueous phase and particles phase were studied. The contents of 20 USEPA priority OCPs in runoff were determined using GC/MS method. The results showed that α-HCH and DDE were detected in runoff particles, but only α-HCH was detected in soluble phase. The concentrations of OCPs of the particle phase in the collected runoff samples of different land-use types decreased in the order: cultivated land (137.35ng/g) >oak forest(43.74ng/g) >orchard (26.89ng/g), and in aqueous phase was: cultivated land(1.94 1.94ng/L) >oak forest(1.90 1.94ng/L) >orchard(1.19 1.94ng/L). The characteristics of OCPs components show that the arable land and orchards were polluted by human, which is also consistent with the local development. The content of OCPs in the same land-use types decreased in the order: 10~15°>5~10°>0~5°. The OCPs concentration increased with the slope in runoff, which is perhaps because the slope had great influences on the generation of the runoff. The source of α-HCH and DDE in the submerged soil and runoff were investigated, which indicated that α-HCH maybe come from the earlier residues and atmospheric deposition. While DDE maybe come from the early application of the pesticide DDT decomposition under aerobic conditions product.
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Received: 20 September 2011
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