Adsorptive treatment of textile wastewater by activated carbon based on peanut shell

Abstract

Approximately 125–150 L of water per kg of textile product produced is consumed in textile industries. Also, during the textile processing, varieties of dyes and chemicals are used, which make textile wastewaters very environmental challenging not only in terms of liquid waste, but also in its chemical composition. In the present study, Activated carbon were prepared from peanut shell and its suitability for the adsorptive removal of Reactive Black 15 (RB-15) dye from aqueous solution have been explored. For this, Dosage study was carried out by varying the adsorbent dosages in the range of 2-30 g/l the natural pH and 300 K. The adsorption of RB-15 dye was studied over a initial pH range of 3–9 at 300K with optimum adsorbent dosage of 20 g/l. The pH of the adsorbate solutions was adjusted using N/10 aqueous solution of either HCl or NaOH. To explore the effect of time on the adsorption process, kinetic study were performed at various C0 values (50-300 mg/l) at optimum dosage of adsorbent (mad) and optimum pH (pHopt), and experimental data were tested for their validation with pseudofirst- order and pseudo-second-order model. Equilibrium adsorption isotherm equations are essential criterion for the design of adsorption systems. Therefore, it is important to establish the most suitable correlation for the equilibrium adsorption. Isothermal experiments were performed at 293, 313 K with C0 values of 25, 50, 100, 150, 200, 250, 300 and 350 mg/l at pHopt and mad of adsorbent .Isotherms such as Freundlich, Langmuir, Redlich-Peterson (R-P) and Tempkin were used to represent the adsorption equilibrium data. It was found that pseudo-second-order kinetic model best fitted the experimental kinetic data, whereas, isothermal study showed that the process is endothermic in nature, and Temkin isotherm best fitted the experimental equilibrium data.