title: Removal of o-nitrobenzoic acid by adsorption on to a new organoclay: montmorillonite modified with HDTMA microemulsion.
abstract: A new organoclay, consisting of montmorillonite modified by a hexadecyl trimethyl ammonium (HDTMA) microemulsion, was synthesized, characterized and used as an adsorbent for the removal of o-nitrobenzoic acid from aqueous solution. Adsorption kinetics, isotherms and effects of operating variables, such as adsorbent dosage, ionic strength and initial solution pH, were also investigated. The results of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis and BET surface area determination indicated that HDTMA molecules had entered into the interlayer of the montmorillonite. The optimized experimental conditions for the adsorption of o-nitrobenzoic acid by montmorillonite modified by HDTMA microemulsion were 0.5 g adsorbent dosage, 0.4 mL of 0.1 mol lbL(-1) CaCl2 solution, initial solution pH of 6.0 and contact time of 6 h. The adsorption isotherms of o-nitrobenzoic acid fitted the Langmuir model well (R2 = 0.9880). The adsorption kinetics data fitted the pseudo-second-order equation (R2 = 0.9999). These above results indicate that montmorillonite modified by an HDTMA microemulsion can be used as adsorbent for o-nitrobenzoic acid because of its high adsorption capacity and low cost.
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, P.R. China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Xin
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Hai-Qin
authors.initials: HQ
authors.lastname: Yu
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.forename: Liang-Guo
authors.initials: LG
authors.lastname: Yan
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D007700:Kinetics; D009579:Nitrobenzoates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: C518437:2-nitrobenzoate; D002593:Cetrimonium Compounds; D004655:Emulsions; D009579:Nitrobenzoates; D014874:Water Pollutants, Chemical; D001546:Bentonite; D000077286:Cetrimonium