title: Bisphenol A sorption by organo-montmorillonite: implications for the removal of organic contaminants from water.
abstract: Remediation of bisphenol A (BPA) from aqueous solutions by adsorption using organoclays synthesized from montmorillonite (MMT) with different types of organic surfactant molecules was demonstrated. High adsorption capacities of the organoclays for the uptake of BPA were observed and these demonstrated their potential application as strong adsorbents for noxious organic water contaminants. The adsorption of BPA was significantly influenced by pH, with increased adsorption of BPA in acidic pH range. However, the organoclays intercalated with highly loaded surfactants and/or large surfactant molecules were less influenced by the pH of the environment and this was thought to be due to the shielding the negative charge from surfactant molecules and the development of more positive charge on the clay surface, which leads to the attraction of anionic BPA even at alkaline pH. The hydrophobic phase created by loaded surfactant molecules contributed to a partitioning phase, interacting with BPA molecules strongly through hydrophobic interaction. Pseudo-second order kinetic model and Langmuir isotherm provided the best fit for the adsorption of BPA onto the organoclays. In addition, the adsorption process was spontaneous and exothermic with lower temperature facilitating the adsorption of BPA onto the organoclays. The described process provides a potential pathway for the removal of BPA from contaminated waters.
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Park
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO 2434, Brisbane, Queensland 4001, Australia; School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, PR China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Sun
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO 2434, Brisbane, Queensland 4001, Australia. Electronic address: g.ayoko@qut.edu.au.
authors.forename: Godwin A
authors.initials: GA
authors.lastname: Ayoko
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO 2434, Brisbane, Queensland 4001, Australia.
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry; D001546:Bentonite / Q000737:chemistry*; D001559:Benzhydryl Compounds / Q000737:chemistry* / Q000302:isolation & purification*; D000077215:Clay; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification*; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification*; D000098826:Bisphenol A Compounds
chemical_list: D000538:Aluminum Silicates; D001546:Bentonite; D001559:Benzhydryl Compounds; D000077215:Clay; D010636:Phenols; D013501:Surface-Active Agents; D014867:Water; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Application; BPA; Environment; Mechanism; Organoclays; Thermodynamics