Kinetic, Isotherm and Thermodynamic Studies of the Adsorption of Thymol Blue onto Powdered Activated Carbons from Garcinia cola Nut Shells Impregnated with H3PO4 and KOH: Non-Linear Regression Analysis
Open Access
- 1 January 2020
- journal article
- research article
- Published by Scientific Research Publishing, Inc. in Journal of Encapsulation and Adsorption Sciences
- Vol. 10 (01), 1-27
- https://doi.org/10.4236/jeas.2020.101001
Abstract
In this work, activated carbons (ACs) prepared by chemical activation of garcinia cola nut shell impregnated with H3PO4 (CBH2/1) and KOH (CBK1/1) were used to study the kinetics, equilibrium and thermodynamics of the adsorption of thymol blue from aqueous solution. The characterization of ACs showed the BET measurements gave surface area and total pore volume respectively of 328.407 m2·g-1 and 0.1032 cm3·g-1 for CBH2/1 and 25.962 m2·g-1 and 0.03 cm3·g-1for CBK1/1; elemental analysis showed a high percentage of carbon in both ACs. Influence of parameters such as initial pH, contact time, adsorbent mass, initial concentration, ionic strength and the effect of temperature on the removal of thymol blue from aqueous solution were studied in batch mode. The studies showed that equilibrium adsorption was attained after 60 minutes for the two ACs, adsorption capacity increased with increasing concentration of thymol blue, and maximum adsorption capacity was obtained at an acidic environment with pH 2. Avrami’s non-linear kinetic expression was the best suited for describing the adsorption kinetics of thymol blue onto ACs, while equilibrium data showed that the three-parameter isotherms better described the adsorption process since R2 > 0.96, and the error functions were lowest for all of them. Maximum adsorption capacity values obtained using the three-parameter Fritz-Schlunder equation were 32.147 mg·g-1 for CBH2/1 and 67.494 mg·g-1 for CBK1/1. The values of the model parameters g and mFS respectively, obtained using the Redlich-Peterson and Fritz-Schlunder III isotherms below 1, showed that the adsorption of thymol blue by the ACs occurred on heterogeneous surfaces. Thermodynamic analyses of the data of the adsorption of thymol blue onto ACs revealed that the adsorption process was temperature dependent, endothermic and spontaneous. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.Keywords
This publication has 35 references indexed in Scilit:
- Adsorption of chromotrope dye onto activated carbons obtained from the seeds of various plants: Equilibrium and kinetics studiesArabian Journal of Chemistry, 2017
- Competitive biosorption of Yellow 2G and Reactive Brilliant Red K-2G onto inactive aerobic granules: Simultaneous determination of two dyes by first-order derivative spectrophotometry and isotherm studiesBioresource Technology, 2010
- Evaluating Adsorption and Biodegradation Mechanisms during the Removal of Microcystin-RR by PeriphytonEnvironmental Science & Technology, 2010
- Preparation of high-surface area activated carbons from Paulownia wood by ZnCl2 activationMicroporous and Mesoporous Materials, 2009
- Modeling of adsorption isotherms of phenol and chlorophenols onto granular activated carbon: Part II. Models with more than two parametersJournal of Hazardous Materials, 2007
- Adsorption in Slit-Like Pores of Activated Carbons: Improvement of the Horvath and Kawazoe MethodLangmuir, 2002
- Dimerization of Cibacron Blue F3GA and other dyes: influence of salts and temperatureDyes and Pigments, 2000
- Pseudo-second order model for sorption processesProcess Biochemistry, 1999
- Application of Elovich Equation to the Kinetics of Phosphate Release and Sorption in SoilsSoil Science Society of America Journal, 1980
- Theory of phase transition kinetics with growth site impingement. I. Homogeneous nucleationJournal of Polymer Science: Polymer Physics Edition, 1974