title: Significance of black carbon in the sediment-water partitioning of organochlorine pesticides (OCPs) in the Indus River, Pakistan.
abstract: This study was conducted with the aim of assessing the levels and black carbon mediated sediment-water partitioning of organochlorine pesticides (OCPs) from the Indus River. ∑OCPs ranged between 52-285 ng L(-1) and 5.6-29.2 ng g(-1) in water and sediment samples respectively. However, the ranges of sedimentary fraction of total organic carbon (f(TOC)) and black carbon (f(BC)) were 0.82-2.26% and 0.04-0.5% respectively. Spatially, OCPs concentrations were higher at upstream sites as compared to downstream sites. Source diagnostic ratios indicated the technical usage of HCH (α-HCH/γ-HCH>4) and significant presence of DDT metabolites with fresh inputs into the Indus River as indicated by the ratios of (DDE+DDD)/∑DDTs (0.27-0.96). The partitioning of OCPs between the sediments and water can be explained by two carbon Freundlich adsorption model which included both organic carbon and black carbon pools as partitioning media.
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
authors.forename: Usman
authors.initials: U
authors.lastname: Ali
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
authors.forename: Anam
authors.initials: A
authors.lastname: Bajwa
authors.affiliation: WWF-Pakistan, Ferozpur Road, PO Box 5180, Lahore 54600, Pakistan.
authors.forename: Muhammad Jamshed
authors.initials: MJ
authors.lastname: Iqbal Chaudhry
authors.affiliation: Department of Biosciences, COMSATS Institute of Information Technology, Islamabad 45550, Pakistan.
authors.forename: Adeel
authors.initials: A
authors.lastname: Mahmood
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jabir Hussain
authors.initials: JH
authors.lastname: Syed
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Gan
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Jones
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: r_n_malik2000@yahoo.co.uk.
authors.forename: Riffat Naseem
authors.initials: RN
authors.lastname: Malik
mesh_terms: D002244:Carbon / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D001556:Hexachlorocyclohexane / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D010154:Pakistan; D010575:Pesticides / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D053260:Soot / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D053260:Soot; D014874:Water Pollutants, Chemical; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; D002244:Carbon
keywords: Adsorption; Black carbon; Indus River; OCPs; Sediment–water partitioning; Two carbon Freundlich model