Remediation of azo dyes by using household used black tea as an adsorbent

Abstract

In the present study used black tea and its impregnates were used as an adsorbents for the removal of textile dyes such as methylene blue and malachite green. The impregnation technique was adopted for the preparation of metal impregnates. The present study shows that used black tea and its impregnate exhibit adsorption tendency for the dyes. By applying batch method, the adsorption process were carried out at various temperatures ranging from 303 to 318 K ± 2 K under the optimized conditions of concentration, stay time and amount of adsorbent. Adsorption isotherm equations such as Freundlich, Langmuir and D-R were applied to calculate the values of respective constants. Thermodynamic parameters like free energy (

G°), enthalpy (H°) and entropy (S°) were also calculated. The results show that used black tea show better adsorption tendency compared to its Impregnates.