Acid Modified Activated Carbon Derived from Chestnut Oak Shells for Adsorption and Removal of Methylene Blue from Aqueous Solution

In this study, an acid-modified-activated carbon was prepared from the chestnut oak shell as raw material. Carbonization followed by modifying with hydrochloric acid /nitric acid (HCl/HNO3) was done. Then the modified adsorbent was used to remove methylene blue from aqueous solutions. Different techniques, including scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and Fourier transform infrared spectroscopy (FTIR), were used for the characterization of the adsorbent. The effects of some experimental parameters, such as pH, adsorbent dosage, contact time, and initial methylene blue concentration, on the removal efficiency were optimized. The optimized parameters were found to be pH, 7, adsorbent dosage, 0.1 g, contact time, 20 min, and initial dye concentration, 50-400 mg L-1. Different Adsorption kinetics and equilibrium were well described by the pseudo-second-order (R2= 0.9996) and the Freundlich model compared to the other investigated models. The maximum adsorption capacity of methylene blue was found to be 406.21 mg g-1 which was superior or comparable to other reported adsorbents. The results indicated that the prepared acid-modified adsorbent is efficient for methylene blue removal in wastewater treatments.