Reactive Blue 5G Adsorption onto Activated Carbon: Kinetics and Equilibrium

Abstract

Adsorption studies are essential before implementation in an industrial plant. We studied the Reactive Blue 5G removal by activated carbon from Pinus sp. Physical and chemical characteristics of the adsorbent were evaluated with N2 adsorption/desorption experiments at 77 K, and equilibrium and kinetics studies were performed in a batch reactor at several temperatures and pH values. Our results showed that the activated carbon had a high surface area, effective diffusion coefficients were of the order of 10–12 cm2·s–1, and mass transfer coefficients were present in both fluid and solid phases. Equilibrium and kinetics experiments confirmed that pH and temperature play an important role: the dye uptake became higher as the temperature and pH decreased, and the optimum removal was at 303 K and pH 2. Finally, thermodynamics analysis suggested that the process is exothermic and chemical in nature. In summary, we showed that activated carbon can be more effective than other adsorbents already used to remove the Reactive Blue 5G from wastewater.