title: Mechanism of adsorption of anionic dye from aqueous solutions onto organobentonite.
abstract: Organobentonite is suggested as potential super-sorbents for the removal of dyes from wastewater. All kinds of organobentonites are synthesized to adsorb dyes; however, the mechanism of the adsorption is still unclear. In this paper, organobentonites were first modified with hexadecyltrimethylammonium bromide at various amounts to reveal the adsorption mechanism. Subsequently, four kinds of organobentonites were utilized to adsorb acid dyes. Results show that the main mechanism of the adsorption of acid dye is an anionic exchange. The counter-ion bromide in the organobentonite was replaced by the dye anion. The study reveals that the adsorption capacity of organobentonite is affected by the surfactant alkyl chain length. When the longer alkyl chain surfactant was modified, bentonite showed higher adsorption capacity. Specific surface areas had no effect on the adsorption. However, the XRD patterns show that interlamellar distance and lamellar distribution have some effects on the adsorption. High adsorption capacity and low residual concentration were obtained by the organobentonite adsorbents. The revelation of the adsorption mechanism makes it possible to obtain more novel and suitable organobentonite adsorbents for anionic dye removal from wastewater.
authors.affiliation: School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu 213164, China. jma@zju.edu.cn
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Ma
authors.forename: Bingying
authors.initials: B
authors.lastname: Cui
authors.forename: Juan
authors.initials: J
authors.lastname: Dai
authors.forename: Dinglong
authors.initials: D
authors.lastname: Li
mesh_terms: D000327:Adsorption; D000838:Anions; D001391:Azo Compounds / Q000737:chemistry; D001546:Bentonite / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013501:Surface-Active Agents; D013816:Thermodynamics; D014867:Water; D014961:X-Ray Diffraction
chemical_list: D000838:Anions; D001391:Azo Compounds; D001557:Benzenesulfonates; D001965:Bromides; D004396:Coloring Agents; D012996:Solutions; D013501:Surface-Active Agents; D014867:Water; D001546:Bentonite; C008710:Orange G; C014722:2-naphthol orange