Adsorption of Naphthalene, Phenanthrene and Pyrene from Aqueous Solution Using Low-Cost Activated Carbon Derived from Agricultural Wastes

In this work, the adsorption of polycyclic aromatic hydrocarbons (PAHs) from aqueous solution by rice husk activated carbon (RHAC) was compared with adsorption using conventional, powdered activated carbon as the adsorbent. The adsorbent capacity of RHAC was found to be higher than all other agricultural and industrial adsorbents evaluated. The kinetics of PAHs was similar even after 24 hours. The removal of PAH occurred in the following order: naphthalene < phenanthrene < pyrene. Our study results show that molecular weight and solubility play vital roles in the adsorption of PAH on RHAC. The study results pointed to the occurrence of an intra-particle mechanism in all cases. The isotherm models that best represented the data obtained were Freundlich for naphthalene, Redlich-Peterson for phenanthrene, and Langmuir for pyrene. The results of this study were compared with previous studies.