Removal of heavy metals from aqueous solution by carbon nanotubes: adsorption equilibrium and kinetics.
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+.
Li
Yan-hui
YH
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. liyanhui@tsinghua.org.cn
Di
Ze-chao
ZC
Luan
Zhao-kun
ZK
Ding
Jun
J
Zuo
Hua
H
Wu
Xiao-qing
XQ
Xu
Cai-lu
CL
Wu
De-hai
DH
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*
D019216:Metals, Heavy; D037742:Nanotubes, Carbon; D017942:Nitric Acid