title: Experimental Study on the Role of Sedimentation and Degradation Processes on Atmospheric Deposition of Persistent Organic Pollutants in a Subtropical Water Column.
abstract: The goal of this study is to experimentally assess the role of vertical sinking and degradation processes of persistent organic pollutants (POPs) in a subtropical water column. This was done by measuring the concentrations of selected typical organochlorine pesticides, including hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), trans-chlordane (TC), and cis-chlordane (CC), in atmosphere (gas phase), water (dissolved and particulate phases), and sedimentation samples simultaneously from October 2011 to April 2013 in a subtropical lake. The fugacity ratios suggested net deposition for α-HCH, γ-HCH, p,p'-DDT, p,p'-DDD, p,p'-DDE, o,p'-DDT, TC, and CC, indicating that the subtropical lake was acting as a "sink" for these chemicals. The enantiomer fractions of α-HCH, o,p'-DDT, TC, and CC in the dissolved phase samples were much more deviated from the racemic values than were those in the air samples, suggesting that these chemicals have suffered microbial degradation in the subtropical lake. In fact, 99% to 100% of atmospheric input of α-HCH and γ-HCH to the subtropical lake was estimated to be depleted via microbial degradation, while the role of hydrolysis and vertical sinking was very small. For more hydrophobic p,p'-DDT, o,p'-DDT, TC, and CC, the role of vertical sinking was 2 to 3 orders of magnitude larger than that for α-HCH and γ-HCH. Microbial degradation was also very important for removing p,p'-DDT, o,p'-DDT, TC, and CC from the water column.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.|School of Environmental Science and Engineering, Guangzhou University , Guangzhou 510006, China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, School of Marine Sciences, Guangxi University , Nanning 530004, China.
authors.forename: Ruijie
authors.identifier: 0000-0002-0246-2204
authors.initials: R
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.
authors.forename: Kechang
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.
authors.forename: Zhineng
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.
authors.forename: Guangcai
authors.initials: G
authors.lastname: Zhong
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: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, China.
authors.forename: Jun
authors.identifier: 0000-0002-3637-1642
authors.initials: J
authors.lastname: Li
mesh_terms: D002706:Chlordan; D004784:Environmental Monitoring; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D014867:Water
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D014867:Water; D002706:Chlordan