Equilibrium, Kinetics and Mechanism of Removal of Methylene Blue from Aqueous Solution by Adsorption onto Pine Cone Biomass of Pinus radiata

• Published in: Water, air, and soil pollution Vol. 218; no. 1-4; pp. 499 - 515
• Main Authors: Sen, Tushar Kanti, Afroze, Sharmeen, Ang, H. M.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2011; Springer; Springer Nature B.V
• Subjects: Adsorbents; Adsorption; Applied sciences; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Barley; Biomass; Chemical properties; Climate Change/Climate Change Impacts; Diffusion coefficient; Dyes; Earth and Environmental Science; Electrons; Energy; Entropy; Environment; Environmental monitoring; Equilibrium; Exact sciences and technology; Free energy; Hydrogeology; Ions; Isotherms; Kinetics; Mathematical models; Metals; Methylene blue; Ovulation; Physicochemical properties; Pine; Pinus radiata; Pollution; Soil Science & Conservation; Studies; Thermodynamics; Water Quality/Water Pollution; Isotherm; Kinetic model; MB adsorption; Diffusion; Enthalpy; Adsorption isotherm; Adsorption capacity; Biomass; Pinus radiata; Modeling; Decontamination; Batchwise; Adsorbent; Diffusion coefficient; Activation energy; Organic compounds; Gibbs free energy; Organic dye; Methylene blue; Thiazine dye; Adsorption; Industrial waste water; Thermodynamic parameter; Kinetics; Physicochemical properties
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-010-0663-y

The kinetics and mechanism of methylene blue adsorption onto raw pine cone biomass ( Pinus radiata ) was investigated under various physicochemical parameters. The extent of the methylene blue dye adsorption increased with increases in initial dye concentration, contact time and solution pH but decreases with the amount of adsorbent, salt concentration and temperature of the system. Overall the kinetic studies showed that the methylene blue adsorption process followed pseudo-second-order kinetics among various kinetic models tested. The different kinetic parameters including rate constant, half-adsorption time and diffusion coefficient are determined at different physicochemical conditions. Equilibrium data were best represented by Langmuir isotherm among Langmuir and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of pine cone biomass was 109.89 mg/g at 30°C. The value of separation factor, R L , from Langmuir equation and Freundlich constant, n , both give an indication of favourable adsorption. Thermodynamic parameters such as standard Gibbs free energy (∆ G 0 ), standard enthalpy (∆ H 0 ), standard entropy (∆ S 0 ) and the activation energy ( A ) were calculated. A single-stage batch absorber design for the methylene blue adsorption onto pine cone biomass has been presented based on the Langmuir isotherm model equation.