Removal of paracetamol from aqueous solutions by activated carbon produced from hazelnut shell

In this thesis study; activated carbon obtained by chemical activation and pyrolysis of hazelnut shell with K2CO3 was used for paracetamol removal from water environments. The activated carbon prepared from hazelnut shell was characterized by elemental analysis, XRD, BET, FTIR, SEM-EDX and pHpzc. Batch adsorption experiments were carried out to demonstrate the adsorption efficiency of the prepared activated carbon. In the adsorption experiments, the effects of initial pH, adsorbent dose, contact time, initial paracetamol concentration and temperature parameters on the adsorption of paracetamol were investigated. The results of the study showed that the paracetamol could be effectively removed at a wide pH range by this activated carbon. The adsorption capacity of the activated carbon increased with the increase of the initial paracetamol concentration, on the contrary, it decreased with the increase of activated carbon dose and temperature. The maximum adsorption efficiency and capacity were obtained at 25 oC. For an initial paracetamol concentration of 10 mg/L, the paracetamol removal efficiency of the activated carbon was found to be 99.2% at pH 7, 0.2 g/L adsorbent dose and 25 oC temperature conditions. The data obtained in the adsorption of paracetamol by activated carbon were applied to the adsorption isotherms and kinetic models. The results showed that the adsorption of paracetamol followed the Langmuir isotherm and pseudo-second-order kinetic model. According to the Langmuir model, the maximum adsorption capacity (qmax) of activated carbon for paracetamol at 25, 35, 45 and 50 oC temperatures was determined as 256.41, 250.00, 243.90 and 238.10 mg/g, respectively. By studying adsorption thermodynamics at various temperatures, thermodynamic parameters were also calculated. Thermodynamic calculations revealed that the adsorption process is spontaneous and exothermic. It was determined that the activated carbon was also effective for real water samples. Desorption studies revealed that the adsorbent can be regenerated and reused for adsorption. The results obtained from the study revealed that the activated carbon produced from hazelnut shell is effective for removal of paracetamol from water environments. In conclusion, this activated carbon can be suggested as a promising adsorbent for the removal of paracetamol from polluted waters.