Purification kinetics of winery wastes by ozonation, anaerobic digestion and ozonation plus anaerobic digestion

The purification of the pollutant organic matter present in winery wastes w as investigated by a single ozonation process, by a single anaerobic digest ion, and by the combined process constituted by an ozonation stage followed by an anaerobic stage. In these processes, the evolution of the pollutant organic load was followed measuring the chemical oxygen demand (COD). The o rganic matter eliminated varied from 20% during single ozonation to 30% dur ing the combination of ozone with UV radiation and hydrogen peroxide. An ap proximate kinetic study was conducted which leaded to the evaluation of the apparent kinetic constants for the COD reduction. These constants ranged b etween 87.5 and 159 L/(mol.h). In the single anaerobic: treatment, almost a total removal of the organic m atter was fulfilled and a methane yield coefficient of 187 mL CH4/g COD deg raded was attained. Finally, in the combined process, the ozonation pretrea tment enhanced the methane production of the latter anaerobic treatment to 215 mL CH4/g COD degraded. Kinetic studies following a modified Monod model were conducted for both anaerobic processes, which allow determining the r ate constants.