Aerobic treatment of black olive wastewater and the effect of an ozonationstage

The reduction of the pollutant organic matter present in wastewaters genera ted in the black olive production process is studied by an aerobic degradat ion, and by the combination of two successive steps: an ozonation pretreatm ent followed by an aerobic degradation. In the single aerobic process, in a ddition to the biomass evolution which is followed during each experiment, the removal of the pollutant load is evaluated by means of global parameter s which are directly related with the organic matter, as the chemical oxyge n demand and the total phenolic compounds content. A kinetic study is perfo rmed by using the Monod model, which applied to the experimental data, prov ides the specific kinetic parameters of this model: the kinetic constant fo r the substrate decomposition rate, the cellular yield coefficient and the kinetic constant for the biomass decrease during the death phase of microor ganisms. In the combined process, an ozonation pretreatment is conducted wi th experiments where the ozone partial pressure is varied, and an important reduction in the phenolic compounds is achieved. The kinetic parameters of the following aerobic degradation stage are also evaluated, and the effect of the chemical oxidation pretreatment on this biological stage is discuss ed.