Pilot-scale produced super activated carbon with a nanoporous texture as an excellent adsorbent for the efficient removal of metanil yellow

Abstract

Super activated carbon (SAC) with a high surface area and pore volume of 3095 m2/g and 2.11 cm3/g, respectively, was produced from raw petroleum coke using a chemical activation method on a pilot-scale basis and assessed as an adsorbent for the removal of metanil yellow. A detailed study, including the influence of pH, contact time, temperature, amount of SAC, and concentration of metanil yellow, was carried out to optimize the operating conditions. The results showed that the SAC obtained had a maximum adsorption capacity for metanil yellow of 937 mg/g at pH 3 and 303 K. The metanil yellow uptake capacity of SAC was highest among the carbon-based adsorbents reported owing to its high surface area, porous texture, and surface functionality, which was sufficient for the 100% decolorization of highly metanil yellow contaminated water (500 mg/g) using 1 g/L of SAC at 303 K and a neutral pH. The thermodynamic and kinetics study showed that the adsorption of metanil yellow on SAC was a spontaneous and exothermic process that was controlled by pseudo-second-order kinetics. The SAC and metanil yellow were both regenerated using methanol as the desorption medium, and the SAC could be reused for the next processes.