title: Adsorption behavior of benzenesulfonic acid by novel weakly basic anion exchange resins.
abstract: Two novel weakly basic anion exchange resins (SZ-1 and SZ-2) were prepared via the reaction of macroporous chloromethylated polystyrene-divinylbenzene (Cl-PS-DVB) beads with dicyclohexylamine and piperidine, respectively. The physicochemical structures of the resulting resins were characterized using Fourier Transform Infrared Spectroscopy and pore size distribution analysis. The adsorption behavior of SZ-1 and SZ-2 for benzenesulfonic acid (BA) was evaluated, and the common commercial weakly basic anion exchanger D301 was also employed for comparison purpose. Adsorption isotherms and influence of solution pH, temperature and coexisting competitive inorganic salts (Na2SO4and NaCl) on adsorption behavior were investigated and the optimum desorption agent was obtained. Adsorption isotherms of BA were found to be well represented by the Langmuir model. Thermodynamic parameters involving ΔH, ΔG and ΔS were also calculated and the results indicate that adsorption is an exothermic and spontaneous process. Enhanced selectivity of BA sorption over sulfate on the two novel resins was observed by comparison with the commercial anion exchanger D301. The fact that the tested resins loaded with BA can be efficiently regenerated by NaCl solution indicates the reversible sorption process. From a mechanistic viewpoint, this observation clearly suggests that electrostatic interaction is the predominant adsorption mechanism. Furthermore, results of column tests show that SZ-1 possesses a better adsorption property than D301, which reinforces the feasibility of SZ-1 for potential industrial application.
authors.affiliation: Department of Municipal Engineering, Southeast University, Nanjing 210096, China. Electronic address: sycyseu@163.com.
authors.forename: Yue
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Municipal Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zuo
authors.affiliation: Department of Municipal Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Junfen
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Municipal Engineering, Southeast University, Nanjing 210096, China.
authors.forename: Rajendra Prasad
authors.initials: RP
authors.lastname: Singh
mesh_terms: D000327:Adsorption; D000837:Anion Exchange Resins / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D013816:Thermodynamics
chemical_list: D000837:Anion Exchange Resins; D001557:Benzenesulfonates; C032365:benzenesulfonic acid
keywords: Adsorption; Benzenesulfonic acid; Desorption; Weakly basic anion exchange resin