Kinetic study of brilliant green adsorption from aqueous solution onto white rice husk ash

• Published in: Journal of colloid and interface science 2013-11, Vol.409, p.112-122
• Main Authors: Tavlieva, Mariana P., Genieva, Svetlana D., Georgieva, Velyana G., Vlaev, Lyubomir T.
• Format: Article
• Language: English
• Subjects: Activation energy; adsorbents; Adsorption; Adsorption kinetics; Aqueous solutions; Ashes; Batch study; Brilliant green; Chemistry; Dye removal; enthalpy; Entropy; equations; Exact sciences and technology; General and physical chemistry; Gibbs free energy; husk ash; Kinetics; Mathematical analysis; Mathematical models; Molecular Structure; Oryza - chemistry; Quaternary Ammonium Compounds - chemistry; Rice; Solutions; Surface physical chemistry; Surface Properties; temperature; Water - chemistry; White rice husk ash
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2013.07.052

[Display omitted] •The WRHA has an adsorption capacity of 85.56mgg−1 for BG at 320K.•Dye removal depends on the temperature, initial dye concentration, and contact time.•Data analysis is carried out using six kinetic models.•The adsorption process obeys the pseudo-second-order kinetic model.•The activation parameters are determined using Arrhenius and Eyring equations. 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 290–320K in 10° steps and in the concentration range of 3–100mgL−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 320K was determined to be 85.56mgg−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 (50.04kJmol−1), the change of entropy (−318.31Jmol−1K−1), enthalpy (−47.50kJmol−1), and Gibbs free energy (range 44.81–54.36kJmol−1) for the formation of activated complex from the reagents.