ABSTRACT
This study investigates the adsorption of Congo red (CR) dye onto corn cob based activated carbon (CCAC) in the batch process. The activated carbon was characterized using FTIR, SEM, and EDX techniques, respectively. The effect of operational parameters such as the initial dye concentration (10–50 mg/L), contact time (5–160 minutes), and solution temperature (30–50°C) were studied. The amount of the CR dye adsorbed was found to increase as these operational parameters increased. Kinetic data for CR dye adsorption onto CCAC were best represented by the pseudo second-order kinetic model. Four different isotherms namely Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models were used to test the adsorption data. It fitted the Langmuir isotherm model most. Thermodynamic parameters such as ΔH0, ΔS0, and ΔG0 were evaluated. The adsorption process was found to be exothermic and spontaneous. The study shows that CCAC is an effective adsorbent for the adsorption of CR dye from aqueous solution.
GRAPHICAL ABSTRACT
Acknowledgments
The corresponding author acknowledges the support obtained from The World Academy of Science (TWAS) in form of grants; Research Grant number: 11–249 RG/CHE/AF/AC_1_UNESCO FR: 3240262674 (2012) and 15–181 RG/CHE/AF/AC_1_: 3240287083 (2015) respectively.