Helen Kalavathy, M.H.Iyyaswami, I.Ganesapillai, M.G.Miranda, L.R.2026-02-052009Colloids and Surfaces B: Biointerfaces, 2009, 70, 1, pp. 35-459277765https://doi.org/10.1016/j.colsurfb.2008.12.007https://idr.nitk.ac.in/handle/123456789/27644Adsorption capacity of Cu2+ from aqueous solution onto H<inf>3</inf>PO<inf>4</inf> activated carbon using rubber wood sawdust (RSAC) was investigated in a batch system. Kinetic and isotherm studies were carried out, the thermodynamic parameters like standard Gibb's free energy (?G°), enthalpy (?H°) and entropy (?S°) were evaluated. The pseudo-second-order model was found to explain the kinetics of Cu2+ adsorption most effectively. The process optimization was performed through Central Composite Rotary Design using response surface methodology (RSM) by Design Expert Version 5.0.7 (STAT-EASE Inc., Minneapolis, USA). An initial concentration of 35 mg L-1, temperature of 26 °C, carbon loading of 0.45 g (100 mL)-1, adsorption time 208 min and pH of 6.5 was found to be the optimum conditions for the maximum uptake of copper ions of 5.6 mg g-1 in batch mode. © 2009 Elsevier B.V. All rights reserved.Adsorption capacitiesAdsorption parametersAdsorption timeAqueous solutionsBatch modesBatch systemsCarbon loadingsCentral composite rotary designsCopper ionsHPO activated rubber wood sawdustInitial concentrationsMinneapolisOptimum conditionsProcess optimizationsPseudo-second order modelsResponse surface methodologyThermodynamic parametersAdsorptionCopperMetal ionsOptimizationRubberSurface propertiesWoodActivated carboncupric ionphosphoric acidadsorption kineticsarticlemathematical modelparameterpH measurementpollution controlpriority journalresponse surface methodsawdustthermodynamicswood dustHydrogen-Ion ConcentrationIonsKineticsModels, TheoreticalPhosphatesRegression AnalysisSurface PropertiesTemperatureThermodynamicsTime FactorsActivated CarbonWood Properties