title: Enhanced reduction of chlorophenols by nanoscale zerovalent iron supported on organobentonite.
abstract: The reactivity of nanoscale zerovalent iron (NZVI) on removing chlorophenols (2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol) was remarkably enhanced by using a hydrophobic support of organobentonite (CTMA-Bent), namely the bentonite modified with organic cetyltrimethylammonium (CTMA) cations. The complete dechlorination of chlorophenols and total conversion into phenol using this novel NZVI/CTMA-Bent combination was observed in batch experiments. The kinetic studies suggested that the reduction of chlorophenols by NZVI was accelerated due to the enhanced adsorption onto CTMA-Bent, which facilitated the mass transfer of chlorophenols from aqueous to iron surface. The enhanced reduction rate by NZVI/CTMA-Bent was positively related to the hydrophobicity of chlorophenols, and an increasing linear relationship was obtained between the relative enhancement on reaction rate constants (k2/k1) and logKow values of chlorophenols. XPS results suggested there were fewer precipitates of ferric (hydro)xides formed on the surface of NZVI/CTMA-Bent, which may also lead to the improved reactivity and repetitive usability of NZVI/CTMA-Bent on removing chlorophenols.
authors: College of Chemistry and Chemical Engineering, Shaoxing University, Zhejiang 312000, PR China. liym@usx.edu.cn
authors: Yimin
authors: Y
authors: Li
authors: Yun
authors: Y
authors: Zhang
authors: Jianfa
authors: J
authors: Li
authors: Guodong
authors: G
authors: Sheng
authors: Xuming
authors: X
authors: Zheng
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D002593:Cetrimonium Compounds / Q000737:chemistry; D002733:Chlorophenols / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D057927:Hydrophobic and Hydrophilic Interactions; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D036103:Nanotechnology; D010084:Oxidation-Reduction
chemical_list: D002593:Cetrimonium Compounds; D002733:Chlorophenols; D001546:Bentonite; D007501:Iron