2015 · 37 citations · 58 references
EngineeringChemical EngineeringEnvironmental EngineeringAnalytical ChemistryChemical KineticsSurface ScienceActivated CharcoalAdsorption At InterfacesAdsorption ProcessesAdsorptive SeparationsIron OxidesSurface AdsorptionActivation EnergyAdsorption IsothermsAdsorption KineticsAdsorption Of ArsenicArsenic RemovalIsothermsLangmuir Adsorption ModelPseudo-second-order Kinetics
In this paper, adsorption of arsenic (As) (III) as arsenite on iron oxide coated granular activated charcoal (FeOGAC) has been studied. Percentage adsorption of As (III) on FeOGAC was determined with respect to pH, contact time and adsorbent dose. The study revealed that the removal of As (III) was best achieved at pH range from 7.5 to 9.5. The initial As (III) concentration (100 µg/L) came down to less than 10 µg/L at contact time 90 min with adsorbent dose of 7.5g/50mL. The adsorption was studied for Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. The Langmuir isotherm model was found to be fitted well. During the study the thermodynamic parameters like enthalpy change ( �H°), free energy change ( �G°), entropy change ( �S°) and activation energy (E a) were determined for the better understanding of the adsorption process. The adsorption was found to be kinetically pseudo-second order controlled process.
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