Preliminary Feasibility Study of Benzo(a)Pyrene Oxidative Degradation by Fenton Treatment

Polycyclic aromatic hydrocarbons (PAHs) are considered priority compounds due to their toxic and carcinogenic nature. The concern about water contamination and the consequent human exposure has encouraged the development of new methods for PAHs removal. The purpose of this work was to study the feasibility of a degradation process of benzo(a)pyrene (BaP) in aqueous matrices by oxidation with Fenton reagent. A laboratory unit was designed to optimize the factors which may influence the process: pH (3.5 to 6.0), temperature (30 to 70 degrees C), H(2)O(2) (20 to 150 mg L(-1)), Fe(2+) concentration (2.75 to 5.50 mg L(-1)), and the initial concentration of the pollutant (10 to 100 mug L(-1)). The pH did not influence significantly the results in the range studied. An increase in temperature from 30 to 70 degrees C improved the removal efficiency from 90% to 100%. The same effect was observed for ferrous ion concentrations from 2.75 to 5.50 mg L(-1) (increase from 78% to 100% removal). The H(2)O(2) concentration played a double role during the process: from 20 to 50 mg L(-1) an increase in the removal efficiency was achieved, but for higher concentrations (>50 mg L(-1)) the degradation is lower. This study proved that the degradation of benzo(a)pyrene by Fenton's reagent is a viable process.