Adsorptive Performance of Termite Mound Clay for Removal of Eosin Yellow Dye from Aqueous Solution

This study investigates the adsorption capacity of termite mound clay (TMC) for the removal of eosin yellow (EY) dye from aqueous systems.Scanned Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used along with some physicochemical properties to characterize the termite mound clay.The adsorption experiment was studied by batch adsorption method with the influence of parameters which include initial dye concentration, contact time, dosage, pH and temperature.The surface of TMC showed functional groups similar to kaolin with flake-like and rough morphology.Efficiency of 99.12% (12.39 mg/g) was achieved at a pH of 3, indicating a pH-dependent adsorption process.The fitness of the equilibrium data into Langmuir isotherm (R 2 =0.9446) with maximum monolayer adsorption capacity of 23.47 mg/g revealed a monolayer coverage of EY on the surface of TMC.The uptake of the dye molecules was rapid within 10 min and the kinetic study was best described by pseudosecond-order model with a rate constant (k 2 ) of 0.271 g/(mg.min).Thermodynamically, the process required little or no heat as a rise in the temperature resulted to decrease in the adsorption capacity and efficiency of TMC on the removal of EY dye.TMC showed potential as a cost-effective adsorbent for the treatment of dye-contaminated water.