title: Simultaneous adsorption of Cd²⁺ and BPA on amphoteric surfactant activated montmorillonite.
abstract: The study mainly investigated the simultaneous adsorption of bisphenol A (BPA) and Cd(2+) from aqueous solution on octadecane-betaine modified montmorillonite (BS-Mt). The characteristics of the obtained materials were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Specific surface area (BET) and Scanning electron microscopy/Energy disperse spectroscopy (SEM/EDS), confirming that BS-18 was successfully introduced into Mt. Also, factors including initial solution pH, initial Cd(2+)/BPA concentration, contact time and adsorbent dosage on the adsorption processes were shown to be crucial for Cd(2+) adsorption, whereas had negligible effects on BPA adsorption. In this study, we found that pseudo-second-order model fitted well with the adsorption kinetic studies for both Cd(2+) and BPA with an equilibrium time of 24 h. The Cd(2+) and BPA adsorption isotherm could be well described by Freundlich model and Langmuir model, respectively. On the basis of kinetic models, the maximum adsorption capacity of Cd(2+) in aqueous solution was slightly enhanced after modification, indicating that Cd(2+) adsorption on BS-Mt was mainly attributed to direct electrostatic attraction and the chelate reaction, while the dramatic enhancement of maximum adsorption capacity for BPA was due to the hydrophobic interaction.
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Chongmin
authors.initials: C
authors.lastname: Liu
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, PR China. Electronic address: pppxwu@scut.edu.cn.
authors.forename: Pingxiao
authors.initials: P
authors.lastname: Wu
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Yajie
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
authors.forename: Lytuong
authors.initials: L
authors.lastname: Tran
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D001559:Benzhydryl Compounds / Q000737:chemistry* / Q000302:isolation & purification*; D002104:Cadmium / Q000737:chemistry* / Q000302:isolation & purification*; 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; D014961:X-Ray Diffraction; D000098826:Bisphenol A Compounds
chemical_list: D001546:Bentonite; D001559:Benzhydryl Compounds; D002104:Cadmium; D010636:Phenols; D013501:Surface-Active Agents; D014867:Water; D014874:Water Pollutants, Chemical; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Amphoteric modification; BPA; Cd(2+); Montmorillonite; Simultaneous adsorption