Application of Licorice-derived Activated Carbon in Tannery Wastewater Treatment

This study used licorice-derived activated carbon to absorb chromium and COD from tannery wastewater. Wastewater used in this research was prepared from Charm Shahr Industrial Estate. First, licorice was converted into activated carbon using zinc chloride as an activator. The licorice-derived activated carbon was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) analysis. Licorice-derived activated carbon was then used to adsorb Cr and COD from tannery wastewater. Factors affecting the adsorption rate, including pH, adsorbent dosage, contact time, and temperature, were investigated. The optimal conditions were pH=7 and adsorbent dosage of 2 g/100 ml. Also, the test time of 30 minutes was determined as the optimal time. Licorice-derived activated carbon adsorbed 99.93% and 99.22% of Cr (III) and COD, respectively. According to the results, Cr and COD adsorption by licorice-derived activated carbon followed the Freundlich isotherm. In addition, Cr and COD adsorption by licorice-derived activated carbon followed the pseudo-second-order kinetic model.