Titolo della tesi: Removal of carbamazepine from water by adsorption using carbonous materials
Pharmaceutical products and their byproducts are considered microcontaminants because of their low concentration in wastewater and superficial water, becoming an environmental problem Among them, carbamazepine, an epileptic drug, is a recalcitrant compound and one of the most difficult to remove in traditional wastewater plants. A large effort has been made to introduce new and more efficient treatment processes for removing these emerging pollutants. Between them,
activated carbon is currently being studied to be implemented in wastewater treatment plants. Moreover, alternative adsorbents, such as biochar has been studied. Biochar is a carbonous material that is used as soil conditional. Because of its similar properties to activated carbon, different studies affirm that biochar can remove contaminants from water. In the present study, carbamazepine removal from the water was conducted using two commercials adsorbents, an activated carbon, (CARBOSORB NC 1240®) and biochar (RE-CHAR®). Batch experiments were performed to assess the potential of this kind these adsorbents for removing carbamazepine from aqueous systems. Moreover, kinetics and isotherm tests were carried out and their experimental data were fixed into different models. From the experimental results, it can be affirmed that CBZ adsorption onto RECHAR™ presented a higher equilibrium adsorption capacity(qe, exp: 97.432 µg/g) reached equilibrium earlier than on CARBOSORB NC 1240™ (qe, exp: 75.816 µg/g). Different Kinetics models were applied and concluding that Pseudo second order and Ritchie models were the most
suitable for CBZ adsorption onto CARBOSORB NC 1240™ while pseudo-second-order and Avrami when RE-CHAR™ was used as adsorbent. Furthermore, Intraparticle diffusion was verified as one of the mechanisms in both adsorbents but not the only one. Regarding isotherms studies, experimental data were successfully fitted with Lagmour and Jonavovich for CARBOSORB NC 1240™ while Redlich-Peterson was the best model for RE-CHAR™. Moreover, it was verified that CBZ adsorption onto both adsorbents at 22°C was a spontaneous process due to their negative △G°. Therefore, the use of these adsorbents kind seems to be an efficient tool for the removal of
carbamazepine. Moreover, biochar is demonstrated to have a great adsorption capacity that encourages further studies.