Photo-Fenton mineralization of synthetic apple-juice wastewater

The mineralization of a synthetic wastewater containing apple juice using a homogeneous photo-Fenton oxidation process was evaluated as an alternative to or a rapid pretreatment step for conventional anaerobic digestion with the aim of considerably reducing the total treatment time. The mineralization process was found to follow pseudo-first-order kinetics. Experimental kinetic constants were fitted using neural networks (NNs) with a 90% confidence level. At the selected operation conditions ([H2O2] = 5800 ppm. [Fe(II)] = 40 ppm, pH = 4.2 and temperature = 26 degrees C), 91% mineralization was achieved in 40 min when treating a synthetic wastewater with 700 ppm of the total organic carbon (TOC). This process can be performed without modifying the natural pH of the wastewater with consequent savings for reagents and a technical simplification of the process. In total, 6.7 mol of H2O2 was consumed per each mol of total organic carbon removed from solution. Finally, the mineralization mechanism was also studied. (C) 2010 Elsevier B.V. All rights reserved.