Two-step wastewater treatment: Sequential ozonation-aerobic biodegradation

Ozonation of wastewater from olive related industries has been carried out after dilution with synthetic urban wastewater. The advantages of the appli cation of different acidic and basic cycles during the ozonation process ha ve been shown. Biodegradability of the final effluent measured as the biolo gical oxygen demand to chemical oxygen demand ratio has significantly been increased (100-144% for table olive wastewater and 24-60% for olive oil was tewater). Aerobic biological experiments conducted by using non-acclimated microorganisms confirmed the suitability of the biodegradation after the ch emical oxidation pre-treatment. A kinetic model based on a free radical mec hanism has been used to simulate experimental results. Both chemical oxygen demand and dissolved ozone concentration profiles are well fitted by the m odel. The aerobic biodegradation process has been modeled by utilizing the Monod equation.