Decontamination of cork wastewaters by solar-photo-Fenton process using cork bleaching wastewater as H_2O_2 source

摘要

This paper reports on a treatment strategy of cork wastewaters through the design of a solar-photo-Fenton process using cork bleaching wastewater as hydrogen peroxide (H_2O_2) source, as a pre-oxidation step, before a conventional biological oxidation process. This method proved to be efficient, achieving mineralization rates higher than 90% for different iron concentrations (20-80 mg Fe L~(-1). Higher iron concentrations resulted in the lower energy consumption and 60 mg Fe L~(-1) was selected as the optimum dose for 91% mineralization and used for biodegradability studies. According to the Zahn-Wellens test, the optimum phototreatment energy to achieve a biodegradable effluent is 13.6 kJUV L~(-1) (65% mineralization), which corresponds to H_2O_2 consumption of 76.1 mM (approximately 8.5 L of cork bleaching wastewater (at 7.7 g H_2O_2 L~(-1)) for 15 L of cork boiling wastewater).