Removal of sulfadiazine from aqueous solution with activated carbon produced using olive pomace

In this study, activated carbon production from olive pomace, waste of olive oil industry, was firstly done. KOH was used as activating agent in the production of activated carbon from olive pomace. In order to investigate the effect of activation temperature and KOH amount on activated carbon properties, activated carbon was produced at different temperatures and impregnation rates. The raw olive pomace and activated carbon from olive pomace were characterized by BET, FTIR, SEM-EDX, TGA-DTA, XRD, and elemental analysis. The increased activation temperature and impregnation ratio led to a larger specific surface area and micropore volume. The highest specific surface area was found to be 2451.770 m2/g at temperature of 840 oC and impregnation ratio of 1:4 (olive pomace:KOH). In the second stage of the study, the removal of sulfadiazine by adsorption onto activated carbon which have the highest surface area among these activated carbons was investigated. The effects of pH, temperature, dosage of adsorbent, contact time, and initial concentration of sulfadiazine on the adsorption process of sulfadiazine onto activated carbon were investigated. Under optimal conditions at pH 7, adsorbent dosage of 8 g/L, sulfadiazine concentration of 20 mg/L, and temperature of 25 oC, the sulfadiazine removal was around 99%. Langmuir and Freundlich isotherm models were investigated to analyze the adsorption equilibrium. It has been found that adsorption of sulfadiazine on activated carbon is best described by Langmuir isotherm. The experimental data was analyzed by pseudo-first order and pseudo-second order models. The maximum adsorption capacity was calculated to be 66.2252 mg/g. The kinetic results fitted to pseudo-second order models. Thermodynamic parameters indicated that adsorption process was spontaneous and exothermic in nature. The obtained results from the study revelaed that the activated crabon from olive pomace was effective in the removal of sulfadiazine.