Kinetic and equilibrium studies of Congo red dye adsorption on cabbage waste powder

Abstract

In this work, the potential of utilizing of dried Cabbage Waste Powder (CWP) as an agro-waste biosorbent for the removal of noxious Congo Red (CR) dye was successfully investigated. FTIR spectroscopic analysis found multiple functional groups on CWP and their interactive effects played important roles in dye removal. Batch experiments were carried out to determine adsorption kinetics and isotherms. Experimental results showed that the rate of adsorption increased with increase in adsorbent weight, dye concentration, pH and decrease in particle size. However, the CR dye removal declined with increased in temperature indicating an endothermic process. Adsorption equilibrium was achieved within 3 h with efficiency of up to 91% at equilibrium. Langmuir adsorption isotherm model, Elovich equation and pseudo-second-order kinetics gave a good fit to the experimental data. Results furnish evidence that CWP is an efficacious, eco-friendly, bio renewable and affordable biomaterial for dye removal from industrial effluents.