Simulated solar photo-assisted decomposition of peroxymonosulfate. Radiation filtering and operational variables influence on the oxidation of aqueous bezafibrate

Abstract

This work investigates the potential of the combination of peroxymonosulfate (PMS) and simulated solar radiation (λ > 300 nm) to remove bezafibrate from aqueous solution. Different solar light filters indicate a higher removal efficiency as the wavelength range used moves to the more energetic region of the solar spectrum. The system PMS/Daylight (300-800 nm) eliminates bezafibrate (1 mg L^-1) in less than 30 min under the best conditions used in this study (C_PMS = 4·10^-4 M) with no pH control (acidic pH). The efficiency of the process significantly improves under alkaline conditions (pH = 10), likely due to a higher PMS photolysis rate. Experiments conducted at different initial concentration of PMS and bezafibrate suggest first order regarding PMS and different from 1 in the case of bezafibrate. Intermediates generated at the beginning of the process have been tentatively identified to propose a hypothetical reaction pathway and to estimate their toxicity.

Keywords: Bezafibrate; Intermediates; Peroxymonosulfate; Simulated solar radiation.