title: p-Nitrophenol, phenol and aniline sorption by organo-clays.
abstract: The aims of this study were to make use of organo-clays (i.e., Cloisite-10A, Cloisite-15A, Cloisite-30B and Cloisite-93A), to remove p-nitrophenol, phenol and aniline of organic pollutants. The organo-clays were characterized by X-ray diffraction (XRD). Sorption isotherm, kinetic and pH effect of p-nitrophenol, phenol and aniline sorbed by four organo-clays were evaluated. The d-spacings (001) of the XRD peak of Cloisite-10A, Cloisite-15A, Cloisite-30B and Cloisite-93A are 1.98, 2.76, 1.93 and 2.64 nm, respectively. The d(001)-spacings of XRD indicated that these p-nitropheno, phenol and aniline could penetrate into the interlayer of clays and expand the d(001)-spacings. The linear sorption isotherm of constant partition was employed to describe the sorption isotherms of phenols sorbed by organo-clays through hydrophobic-hydrophobic chemical reactions. The parabolic diffusion and power-function of kinetic models were employed to describe properly the kinetic experiments. The rate limiting step of the p-nitrophenol sorption reactions on organo-clays were diffusion-controlled processes (i.e., 15A, 30B, 93A) and chemical-controlled process for 10A organo-clays. The pre-exponential factor of the p-nitrophenol sorbed by four organo-clays showed the trend as follows: 10A> 30B> 93A> 15A. The efficiency of these organo-clays in removing phenol compounds in water treatments merit further study.
authors.affiliation: School of Forestry and Resource Conservation, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chun Han
authors.initials: CH
authors.lastname: Ko
authors.forename: Chihhao
authors.initials: C
authors.lastname: Fan
authors.forename: Po Neng
authors.initials: PN
authors.lastname: Chiang
authors.forename: Ming Kuang
authors.initials: MK
authors.lastname: Wang
authors.forename: Kuo Chuan
authors.initials: KC
authors.lastname: Lin
mesh_terms: D000327:Adsorption; D000478:Alkylation; D000538:Aluminum Silicates / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D000077215:Clay; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015394:Molecular Structure; D009574:Nitro Compounds / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D000814:Aniline Compounds; D009574:Nitro Compounds; D010636:Phenols; D000644:Quaternary Ammonium Compounds; C023650:aniline; D000077215:Clay