Adsorption of Selected Textile Dyes onto Chemically Activated Carbon Adsorbents Prepared Using Waste Biomass Bauhinia racemosa Fruit pods

Abstract

Environmental pollution is one of the greatest problems that the world is facing today. The textile dyeing and finishing industry has created huge pollution problem as it is one of the most chemically intensive industries on earth and major polluter of fresh water. Among the various water treatment methods, adsorption process is considered to be a very effective technique in terms of simplicity of design, ease of operation and lower cost. Thus the work is aimed to study the Adsorption of Selected Textile Dyes onto Chemically Activated Carbon Adsorbents Prepared Using Waste Biomass Bauhinia racemosa fruit pods. The eco-friendly activated carbon was prepared from waste bio-mass Ripened Bauhinia racemosa fruit pods by sulphuric acid activation (BR-SAC) and phosphoric acid activation process (BR-PAC). The feasibility of the removal of Crystal Violet (CV), Acid Blue 110 (AB 110), Reactive Black 5 (RB 5) and Congo Red (CR) dyes were carried out by batch mode adsorption experiments using the prepared adsorbents by changing the parameters such as Initial dye concentration, Dosage of adsorbent, pH and Temperature. newlineThe kinetics of adsorption of CV, AB110, RB5 and CR dyes were studied using Lagergren pseudo-first order, Elovich and Intraparticle diffusion rate equations. The adsorption data fitted with two well known adsorption isotherms Langmuir and Freundlich to determine adsorption equilibrium. Thermodynamic parameters such as Gibbs free energy change (and#916;G), the enthalpy change (and#916;H) and the entropy change (and#916;S) for the adsorption of CV, AB 110, RB 5 and CR dyes from aqueous solution onto BR-SAC and BR-PAC adsorbents were determined. The surface morphology of both the adsorbents (BR-SAC and BR-PAC) have been visualized by using Field Emission Scanning Electron Microscope (FESEM) before and after adsorption of the dyes. The BET Surface areas of the adsorbents BR-SAC, BR-PAC and CAC are 288.700 m2/g 1083.440 m2/g, 1137.962 m2/g respectively Dye removal efficiency of the adsorbent BR-PAC was higher than the adsorbent BR-SAC