Degradation of the antibiotic chloramphenicol by photo-Fenton process at lab-scale and solar pilot plant: Kinetic, toxicity and inactivation assessment

Abstract

In this study we evaluated the feasibility of application of photo-Fenton process in the treatment of aqueous solution contaminated by chloramphenicol (CAP). The results suggest that the concentration of H2O2 and the concentration of Fe2+ influence the degradation efficiency of this antibiotic. The best efficiency at lab-scale was achieved when the concentration of H2O2 was equal to 400mgL−1, while only a small improvement was observed when the concentration of H2O2 increased from 400 to 500mgL−1. A concentration of 750mgL−1 was necessary in the process mediated by solar radiation, probably due to thermal decomposition of H2O2. The concentration of Fe2+ influences positively the rate of CAP and COD removal. A significant increase was observed between 5 and 10mgL−1, remaining constant from 10 to 15mgL−1. On the other hand, the mode of addition of H2O2 (single or multiple additions) did not influence the rate of CAP removal. Thus, the option was for simple addition. Finally, the results suggest that the degradation of CAP by photo-Fenton process can be performed on a large scale, yielding oxidized by-products of low toxicity and without antimicrobial activity. The use of solar radiation was feasible in the treatment of waters containing this kind of pollutant, which is extremely advantageous, since the energy costs of the process can be reduced.