Dissolved oxygen concentration: A key parameter in monitoring the photo-Fenton process

Dissolved oxygen concentration variations have been investigated during the photo-Fenton process. Using Paracetamol as a model pollutant and dissolved organic carbon (DOC) removal as the priority objective, we have studied the effects of irradiance intensity (13-87W/m(2)), iron concentration (0.09-0.45 mM), hydrogen peroxide concentration (9-45 mM) and finally DOC concentration (4-25 mM) on the relationship between the mineralization rate, the H(2)O(2) reaction rate and the oxygen generation rate. A high level of oxygen generation is indicative of inefficient conditions whereas a decrease in dissolved oxygen concentration (i.e. generation rates near to zero) indicates a lack of hydrogen peroxide. As a consequence, dissolved oxygen monitoring has been presented as an easy, measurable tool for studying the evolution of the photo-Fenton process and its efficiency. (C) 2011 Elsevier B.V. All rights reserved.