Source and Migration of Short-Chain Chlorinated Paraffins in the Coastal East China Sea Using Multiproxies of Marine Organic Geochemistry

摘要

Multiple proxies of terrestrial organic matters (TOM) were introduced to study the migration behaviors of short-chainrnchlorinated paraffins (SCCPs) in the coastal East China Sea (ECS).rnThe contents of SCCPs in the surface sediment collected fromrnChangjiang (Yangtze) River Delta (CRD) and along the Zhejiang-rnFujian coastline ranged from 9.0 to 37.2 ng/g (dry weight, d.w.),rndisplaying a "band-style" distribution trend. Spatial distributionrnpatterns of SCCP congeners presented an increasing trend seawardrnand southward along the coastline for shorter carbon length (C_(10) +rnC_(11)) and lower chlorinated (Cl_5 + Cl_6 + Cl_7) congeners, suggesting arnspreading tendency seaward and southward from the CRD and thernnorth of the inner shelf The significant relationship between ∑SCCPsrnand total organic carbons (TOC) (r~2 = 0.402, p ＜ 0.05) indicated thatrnthe migration of SCCPs in sediments was markedly affected by TOC.rnThe spatial patterns of the TOM proxies of TOC δ~(13)C, the contents of ∑C_(27)+C_(29)+C_(31) n-alkanes, terrestrial marine biomarkerrnratio (TMBR), and terrestrial TOC (T-TOC) were all similar to that of ∑SCCPs. Linear relationships between SCCP contentsrnand both the contents of ∑C_(27)+C_(29)+C_(31) n-alkanes (r~2 = 0.537, p ＜ 0.05) and T-TOC (r~2 = 0.495, p ＜ 0.05) were also observed.rnThe consistence demonstrated that a major portion of sedimentary SCCPs in the coastal ECS should be from the river input ofrnChangjiang River and deposited in the CRD and along the inner shelf of the ECS, but only a minor fraction was transported tornthe offshore areas.