Antibiotic removal from aqueous environment by activated carbon prepared from hazelnut shell

In this thesis, the removal of sulfamethoxazole (SMZ) and trimethoprim (TMP) antibiotics from aqueous medium by activated carbon obtained from hazelnut shell was investigated. In the first stage of the study, the activated carbon was prepared from hazelnut shell by using KOH and K2CO3 together as activators. The activated carbon prepared hazelnut shell was characterized by BET, FTIR, SEM-EDX, XRD and elemental analysis. In the second stage of the study, the removal of SMZ and TMP antibiotics from the aqueous medium by activated carbon prepared from hazelnut shell was investigated. The effects of solution pH, activated carbon amount, contact time, initial antibiotic concentration and temperature on the SMZ and TMP adsorption process of activated carbon were examined. Appropriate pH values for SMZ and TMP adsorption were determined as pH 4 and pH 7, respectively. It was showed that the adsorption efficiency of antibiotics decreased and the adsorption capacity increased with increasing initial antibiotic concentration for both antibiotics. The SMZ and TMP removal efficiencies at an initial antibiotic concentration of 20 mg/L and a temperature of 30 oC were found as 99.2% and 99.9%, respectively. The maximum efficiency and capacity of adsorption were obtained at temperature of 50 oC. The experimental results obtained for each antibiotic at 30, 40 and 50 oC were applied to the Langmuir and Freundlich isotherms. It was observed that the Langmuir model better described the adsorption equilibrium for both antibiotics. According to the Langmuir model, the maximum adsorption capacity (qmax) of activated carbon for SMZ antibiotic at temperatures of 30, 40 and 50 oC was determined as 212.77, 238.09 and 256.41 mg/g, respectively. For TMP antibiotic at the same temperatures, it was calculated as 121.95, 129.87 and 140.85 mg/g. The experimental results obtained in the adsorption of SMZ and TMP antibiotics by activated carbon were applied to the pseudo first and second order kinetic models and their kinetic constants were calculated. The obtained results showed that the adsorption of SMZ and TMP by activated carbon followed the pseudo second order kinetic model. The results obtained from the study revealed that the activated carbon prepared from hazelnut shell was effective in removing SMZ and TMP. In conclusion, this activated carbon can be used as a promising adsorbent in the effective removal of SMZ and TMP from water and wastewater.