Evaluation of operating parameters involved in solar photo-Fenton treatment of wastewater: Interdependence of initial pollutant concentration, temperature and iron concentration

A mixture of five commercial pesticides (Vydate®, Metomur®, Couraze®, Ditimur-40® and Scala®) commonly used in intensive agriculture has been selected as an example of highly toxic, non-biodegradable wastewater to be treated by solar Photo-Fenton. The effect of the total concentration of organics as dissolved organic carbon (100–500 mg/L), operating temperature (25–50 °C), dissolved iron concentration and their relationship to different process efficiency parameters (mineralization rate, hydrogen peroxide consumption and treatment time) were evaluated. Experiments were carried out under sunlight in a pilot plant. It consists of four compound parabolic collectors (CPCs) and a total volume of 75 L. From the results of the study it can be concluded that solar plants should be designed for operating at temperatures below 45 °C to avoid significant loss of iron. H2O2 should be carefully dosed during the photo-Fenton treatment to avoid its continued excess and inefficient use.