title: Sequestration of HCHs and DDTs in sediments in Dongting Lake of China with multiwalled carbon nanotubes: implication for in situ sequestration.
abstract: Organochlorine pesticides (OCPs) in sediments could be released into water, posing great threats to human health and organisms. In this study, the treatment effectiveness of in situ sequestration of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethane (DDTs) in sediments was explored using multiwalled carbon nanotubes (MWCNTs) as adsorbents. Physicochemical tests (aqueous equilibrium concentrations, semipermeable membrane device (SPMD) uptake, and quiescent flux to overlying water) were conducted to evaluate the sequestration effectiveness of MWCNTs. Compared to the control, the MWCNT-treated sediments showed great reductions of HCHs and DDTs in aqueous equilibrium concentrations, SPMD uptake, and quiescent flux to overlying water. And the effects of dose of MWCNTs, diameter of MWCNTs, and contact time between MWCNTs and sediments on sequestration effectiveness were studied. Increased dose, decreased MWCNT diameter, and prolonged contact time resulted in a better sequestration effectiveness. The results indicated that the addition of MWCNTs to sediment could reduce the content of HCHs and DDTs released from sediments, reducing bioavailability of HCHs and DDTs and minimizing risks to ecosystem and human. MWCNTs have potential applications as adsorbents for in situ treatment of OCP-contaminated sediments.
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Guo
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
authors.forename: Cui
authors.initials: C
authors.lastname: Lai
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China. zgming@hnu.edu.cn.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China. zgming@hnu.edu.cn.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China. jilaigong@gmail.com.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China. jilaigong@gmail.com.
authors.forename: Jilai
authors.initials: J
authors.lastname: Gong
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
authors.forename: Chang
authors.initials: C
authors.lastname: Su
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Yang
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.|Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, People's Republic of China.
authors.forename: Piao
authors.initials: P
authors.lastname: Xu
mesh_terms: D000327:Adsorption; D002681:China; D003634:DDT / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D019015:Geologic Sediments / Q000737:chemistry*; D001556:Hexachlorocyclohexane / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification*; D060106:Lakes / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012306:Risk; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D001556:Hexachlorocyclohexane; D003634:DDT
keywords: Bioavailability; DDTs; HCHs; In situ sediment treatment; Multiwalled carbon nanotubes; Physicochemical tests; Sequestration effectiveness