title: Kinetic study of brilliant green adsorption from aqueous solution onto white rice husk ash.
abstract: The present research was focused on the study of adsorption kinetics of brilliant green (BG) onto white rice husk ash from aqueous solutions. The research was performed in the temperature interval 290-320 K in 10° steps and in the concentration range of 3-100 mg L(-1). Batch studies were conducted in order to determine the optimal adsorbent dose, and the time required to reach the adsorption equilibrium at each temperature. The effect of the initial concentration of brilliant green was studied (pH not adjusted), as well as the effect of temperature. The maximum adsorption capacity of the WRHA for BG at 320 K was determined to be 85.56 mg g(-1). The adsorption kinetic data were analyzed employing several kinetic models: pseudo-first-order equation, pseudo-second-order equation, Elovichequation, Banghman's equation, Diffusion-chemisorption model, and Boyd kinetic expression. It was established that the adsorption process obeyed the pseudo-second-order kinetic model. Based on the rate constants obtained by this kinetic model using Arrhenius and Eyring equations, the activation parameters were determined, namely the activation energy (50.04 kJ mol(-1)), the change of entropy (-318.31 J mol(-1) K(-1)), enthalpy (-47.50 kJ mol(-1)), and Gibbs free energy (range 44.81-54.36 kJ mol(-1)) for the formation of activated complex from the reagents.
authors: Department of Physical Chemistry, Assen Zlatarov University, 8010 Burgas, Bulgaria. Electronic address: mariana_tavlieva@btu.bg.
authors: Mariana P
authors: MP
authors: Tavlieva
authors: Svetlana D
authors: SD
authors: Genieva
authors: Velyana G
authors: VG
authors: Georgieva
authors: Lyubomir T
authors: LT
authors: Vlaev
mesh_terms: D000327:Adsorption; D007700:Kinetics; D015394:Molecular Structure; D012275:Oryza / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D000644:Quaternary Ammonium Compounds; D012996:Solutions; D014867:Water; C006798:brilliant green
keywords: Adsorption kinetics; Batch study; Brilliant green; Dye removal; White rice husk ash