A comparative study of photocatalytic degradation of 3-chloropyridine under UV and solar light by homogeneous (photo-Fenton) and heterogeneous (TiO2) photocatalysis

[Display omitted] ► Photo-Fenton process is ca. 5 times faster than TiO2 photocatalysis. ► Complete mineralization using sun light and results at lab-scale well extrapolated to larger scale. ► Some intermediates more toxic than 3-chloropyridine formed as the reaction proceeds. ► Photo-Fenton process quite sensitive to the presence of phosphate. Photocatalytic degradation of 3-chloropyridine in the homogeneous (photo-Fenton) and heterogeneous (TiO2) phase was studied using both UV and sun light. Complete mineralization was achieved in both cases though times required in photo-Fenton process were ca. 5 times shorter under our experimental conditions. Results found at lab scale (solar simulator) were successfully extrapolated to a larger scale (30L) thus evidencing the validity of the method for treatment of waters polluted with this kind of chemical. Toxicity tests (Vibrio fischeri) showed that some intermediates more toxic than 3-chloropyridine were formed as reaction proceeded.