title: Removal of heavy metals from aqueous solution by carbon nanotubes: adsorption equilibrium and kinetics.
abstract: Carbon nanotubes prepared by catalytic chemical vapor deposition of hydrocarbon at 650 degrees C show good adsorption capability of Pb2+, Cu2+ and Cd2+ ions from aqueous solution after oxidized with concentrated nitric acid at 140 degrees C for 1 h. The specific surface area and particle size distribution of the as-grown and oxidized CNTs were studied by BET method and laser particle analyzer. Three kinetic models, that is, first-, pseudo second- and second-order, were used to investigate the adsorption data and the pseudo second-order model can represent the experimental data better than two others. The equilibriumdata fitted well with the Langmuir model and showed the following adsorption order: Pb2+ > Cu2+ > Cd2+.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. liyanhui@tsinghua.org.cn
authors.forename: Yan-hui
authors.initials: YH
authors.lastname: Li
authors.forename: Ze-chao
authors.initials: ZC
authors.lastname: Di
authors.forename: Zhao-kun
authors.initials: ZK
authors.lastname: Luan
authors.forename: Jun
authors.initials: J
authors.lastname: Ding
authors.forename: Hua
authors.initials: H
authors.lastname: Zuo
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Wu
authors.forename: Cai-lu
authors.initials: CL
authors.lastname: Xu
authors.forename: De-hai
authors.initials: DH
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D007700:Kinetics; D019216:Metals, Heavy / Q000737:chemistry*; D008854:Microscopy, Electron; D008956:Models, Chemical; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D017942:Nitric Acid; D010316:Particle Size; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D019216:Metals, Heavy; D037742:Nanotubes, Carbon; D017942:Nitric Acid