title: Cationic polyelectrolyte/bentonite prepared by ultrasonic technique and its use as adsorbent for Reactive Blue K-GL dye.
abstract: In this study, the cationic polyelectrolyte polyepicholorohydrin-dimethylamine (EPI-DMA) was intercalated into bentonite using ultrasonic. The structure of EPI-DMA/bentonite and its adsorption of Reactive Blue K-GL (RB K-GL) dye were investigated. Compared with raw bentonite, the EPI-DMA/bentonite had larger interlayer spacing and was more hydrophobic, providing with better surface properties for adsorption. The adsorption of RB K-GL on EPI-DMA/bentonite was described by the adsorption models of Langmuir, Freundlich and Dubinin-Radushkevic. The adsorption kinetics was analyzed using pseudo-first- and second-order kinetic models and intraparticle diffusion model. Results showed that both the intraparticle diffusion and first-order adsorption occur in the initial period of adsorption, and that pseudo-second-order kinetic model was more suitable for describing the whole adsorption process. The reaction rates were also calculated. The changes of free energy, enthalpy and entropy of adsorption were evaluated for the adsorption of RB K-GL onto EPI-DMA/bentonite, suggesting that the adsorption process was spontaneous and exothermic.
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan 250100, Shandong, PR China. liqian@mail.sdu.edu.cn
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Qin-Yan
authors.initials: QY
authors.lastname: Yue
authors.forename: Yuan
authors.initials: Y
authors.lastname: Su
authors.forename: Bao-Yu
authors.initials: BY
authors.lastname: Gao
authors.forename: Lin
authors.initials: L
authors.lastname: Fu
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000302:isolation & purification*; D001546:Bentonite / Q000138:chemical synthesis / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D004058:Diffusion; D007700:Kinetics; D013449:Sulfonamides / Q000302:isolation & purification*; D013816:Thermodynamics; D014465:Ultrasonics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; C525155:Reactive Blue K-GL dye; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D001546:Bentonite