title: Adsorption of diuron, fluridone and norflurazon on single-walled and multi-walled carbon nanotubes.
abstract: The sorption behaviors of diuron (DIU), fluridone (FLU) and norflurazon (NOR) by a single-walled carbon nanotube (SWCNT) and three multi-walled carbon nanotubes (MWCNT) samples including MWCNT10 (<10nm, outer diameter), MWCNT20 (10-20 nm), and MWCNT40 (20-40 nm) were investigated. All adsorption isotherms were nonlinear and were well fitted with the Freundlich model and Dubinin Ashtakhov (DA) model. The linear relationships between the organic carbon (OC)-normalized saturated adsorption capacity (Q(0)(OC)) and surface area (SA) suggest that SA is presumably responsible for the adsorption of DIU and NOR on CNTs. While FLU, DIU, and NOR OC-normalized distribution coefficients (logK(OC)) of CNTs increased with increasing their hydrophobicity (logK(OW)) and the positive relationships between the logK(OW)-normalized logK(OC) (i.e., logK(OC)/logK(OW)) of FLU, DIU, and NOR and their hydrogen bonding ability indicate that the adsorption of FLU, DIU and NOR was mainly controlled by the hydrophobic interaction and hydrogen bonding. The higher logK(OC) or Q(0)(OC) values of MWCNT10 and SWCNT relative to other large MWCNTs and carbonaceous adsorbents suggest that MWCNT10 has the potential to serve as an adsorbent used to reduce the mobility of herbicides in agricultural and environmental applications.
authors.affiliation: State Key Laboratory of Water Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. sunke@bnu.edu.cn
authors.forename: Ke
authors.initials: K
authors.lastname: Sun
authors.forename: Zheyun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Ziying
authors.initials: Z
authors.lastname: Wang
authors.forename: Dongyu
authors.initials: D
authors.lastname: Xu
authors.forename: Jie
authors.initials: J
authors.lastname: Jin
authors.forename: Xitao
authors.initials: X
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D004237:Diuron / Q000302:isolation & purification*; D004787:Environmental Pollution / Q000517:prevention & control; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006540:Herbicides / Q000302:isolation & purification*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011724:Pyridazines / Q000302:isolation & purification*; D011728:Pyridones / Q000302:isolation & purification*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D006540:Herbicides; D037742:Nanotubes, Carbon; D011724:Pyridazines; D011728:Pyridones; C013351:fluridone; D004237:Diuron; C008677:norflurazone