Colour removal from aqueous solution of tar-chromium green 3G dye using natural diatomite

Removal of Tar-Chromium Green 3G dye from aqueous solution at different dye concentrations, different temperatures and adsorbent doses has been studied. It was seen that the maximum of 88% adsorption has been achieved from the wastewater using 3.0 g material at 30oC temperature for shaking time of 60 min.The adsortion isotherms are described by means of the Langmuir and Freudlich isotherms at different temperatures of 25, 30 and 35C, and the results were discussed. The equilibrium data satisfied both the Langmuir and Freundlich models. Moreover, thermodynamic parameters such as ΔH, ΔS and ΔG were also studied. It was found that the values of standard free energy (ΔG) and the values of standard enthalpy (ΔH) were negative and entropy (ΔS) was found to be positive. Thermodynamic studies showed that the reaction for uptake by diatomite is exohtermic in nature.The results of this study showed that diatomite could be employed as effective and low-cost materials for the removal of the dye from aqueous solution.