The Adsorption of Malachite Green from Industrial Wastewater by Oxidized Black Tea Adsorbent

An Eco-friendly and low-cost adsorbent surface was prepared from oxidized black tea leaves for adsorption of Malachite Green (MG) dye by batch equilibrium adsorption technique and investigated the optimum conditions that include dose of adsorbent, contact time, adsorbent particle size, pH, and initial concentration of the dye. All adsorption measurements were performed using spectrophotometry at 618 nm, the maximum wavelength of MG. Maximal adsorption was obtained at 1.0 g of oxidized black tea leaves with a contact time of 120 min. The optimal pH was 8. The maximum adsorption capacity was 97.8 mg g-1. The physic processes were used to prepare the adsorbent surface from oxidized black tea leaves. These included boiling the oxidized black tea leaves for 10 hours using distilled water, filtering, washing, and drying at 80°C. Physic preparation gave a suitable surface for the adsorption process. The adsorption of MG on the surface of tea leaves obeyed the Freundlich and Langmuir equations in adsorption. Isotherm parameters of Freundlich and Langmuir modules were estimated.