title: Isotherm and thermodynamic studies of Zn (II) adsorption on lignite and coconut shell-based activated carbon fiber.
abstract: The Zn (II) adsorption capacity of lignite and coconut shell-based activated carbon fiber (ACF) was evaluated as a function of initial Zn (II) concentration, temperature and contact time in batch adsorption process in this study. Adsorption uptake increased with initial Zn (II) concentration and temperature. Optimal contact time for the adsorption of Zn (II) ions onto lignite and coconut shell-based ACF was found to be 50 min. Removal percentage decreased from 88.0% to 78.54% with the increment in initial Zn (II) concentration from 5 to 50 mg L(-1). Equilibrium data fit well with Langmuir-I isotherm indicating homogeneous monolayer coverage of Zn (II) ions on the adsorbent surface. Maximum monolayer adsorption capacity of Zn (II) ions on ACF was found to be 9.43 mg g(-1). Surface morphology and functionality of ACF prior to and after adsorption were characterized by electron microscopy and infrared spectroscopy. Various thermodynamic parameters such as standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°) were evaluated.
authors.affiliation: School of Civil and Environmental Engineering, Kumoh National Institute of Technology, Gumi 730-701, Republic of Korea. scientist.nepalensis@gmail.com
authors.forename: Sohan
authors.initials: S
authors.lastname: Shrestha
authors.forename: Guntae
authors.initials: G
authors.lastname: Son
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Lee
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D003031:Coal; D003059:Cocos / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D000077482:Carbon Fiber; D003031:Coal; D014874:Water Pollutants, Chemical; D002244:Carbon; D015032:Zinc
keywords: Activated carbon fiber; Adsorption; Isotherm; Thermodynamic parameters