title: Remediation of organochlorine pesticides contaminated lake sediment using activated carbon and carbon nanotubes.
abstract: Organochlorine pesticides (OCPs) in sediment were a potential damage for humans and ecosystems. The aim of this work was to determine the effectiveness of carbon materials remedy hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethanes (DDTs) in sediment. Two different carbon materials including activated carbon (AC) and multi-walled carbon nanotubes (MWCNTs) were used in the present research. Sediment treated with 2 wt% AC and MWCNTs after 150 d contact showed 97%, and 75% reduction for HCH, and 93% and 59% decrease for DDTs in aqueous equilibrium concentration, respectively. Similarly, the reduction efficiencies of DDT and HCH uptake by semipermeable membrane devices (SPMDs) treated with AC (MWCNTs) were 97% (75%) and 92% (63%), respectively under the identical conditions. Furthermore, for 2 wt% AC (MWCNTs) system, a reduction of XAD beads uptake up to 87% (52%) and 73% (67%) was obtained in HCH and DDT flux to overlying water in quiescent system. Adding MWCNTs to contaminated sediment did not significantly decrease aqueous equilibrium concentration and DDTs and HCH availability in SPMDs compared to AC treatment. A series of results indicated that AC had significantly higher remediation efficiency towards HCH and DDTs in sediment than MWCNTs. Additionally, the removal efficiencies of two organic pollutants improved with increasing material doses and contact times. The greater effectiveness of AC was attributed to its greater specific surface area, which was favorable for binding contaminants. These results highlighted the potential for using AC as in-situ sorbent amendments for sediment remediation.
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Hua
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, PR China. Electronic address: jilaigong@gmail.com.
authors.forename: Ji-Lai
authors.initials: JL
authors.lastname: Gong
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, PR China.
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, PR China.
authors.forename: Fu-Bing
authors.initials: FB
authors.lastname: Yao
authors.affiliation: College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Guo
authors.affiliation: China National Engineering Research Center for Agrochemicals, Hunan Research Institute of Chemical Industry, Changsha 410014, PR China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Ou
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D002681:China; D003634:DDT / Q000032:analysis; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005843:Geography; D019015:Geologic Sediments / Q000737:chemistry; D001556:Hexachlorocyclohexane / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D060106:Lakes / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis; D012995:Solubility; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D037742:Nanotubes, Carbon; D010575:Pesticides; D014874:Water Pollutants, Chemical; D014867:Water; D002606:Charcoal; D001556:Hexachlorocyclohexane; D003634:DDT
keywords: Activated carbon; Dichlorodiphenyltrichloroethane; Hexachlorocyolohexane; Multi-walled carbon nanotubes; Remediation; Sediment