ABSTRACT
This study focused on the adsorption of crystal violet (CV) dye from aqueous solution using original and modified periwinkle-clay rooftile composite. The aim of the experiment was to treat simulated textile wastewater (crystal violet dye) using periwinkle-clay rooftile composite as catalyst.
Batch experiment was carried out to examine the viability of using periwinkle-clayrooftile for adsorption of CV dye from aqueous solutions under different process conditions. The catalyst dosage was varied from 1g to 3.0g, pH of 3-11, contact time from 30min to120 min, initial concentration from 20mg/l to 100mg/l and temperature from 313k to 353k.
The result revealed that removal of CV increased with contact time, adsorbent dose, temperature, ionic strength but decrease with initial dye concentration (from 80mg/l and above).
The optimum values of catalyst dosage, pH and contact time were gotten to be (2.5g, 11 and 120 minutes) for the modified catalyst and these reduced our dye concentration present to 98%, 87% and 80% respectively. Using the unmodified catalyst, our optimal values of catalyst dosage, pH and contact time were gotten to be (2g, 9.0 and 120 minutes) and these reduced our dye concentration present by 98%, 98% and 97.6%. Pseudo-second-order kinetic model was best used to describe sorption kinetics for modified and unmodified catalyst with R2 value of 0.9995 and 0.9962 respectively while Freundlich isotherm model for modified catalyst with R2=0.9096 and Temkin isotherm was appropriate for describing adsorption isotherm of unmodified catalyst with R2 value of 0.8711 .The results demonstrated that the unmodified form of periwinkle-clayrooftile catalyst is a more effective adsorbent for dyes removal from industrial effluents.
