Modelling Industrial Wastewater Ozonation In Bubble Contactors. 1. Rate Coefficient Determination

Abstract

A study of the ozonation of distillery and tomato wastewaters was carried out in a small bubble contactor in order to obtain kinetic data for scaling-up. Thus, several parameters, such as chemical oxygen demand (COD), 254 nm absorbance (A₂₅₄) and organic carbon content (OC), were followed during ozonation at different experimental conditions.

For distillery wastewaters all parameters investigated have the highest decreases during the first minutes of ozonation, A₂₅₄ showing the highest disappearance rates. Thus, during the first fifteen minutes of ozonation an important decrease of the 254 nm absorbance (˜ 75%) was observed. At further reaction times values of all parameters studied decrease slowly, eventually reaching a plateau value. During approximately the first two hours of reaction, dissolved ozone was never found, which suggested that fast or moderate gas-liquid reactions took place in the wastewaters.

Key Words:

• Ozone
• Industrial Wastewater Treatment
• Wastewater Ozonation
• Ozonation Kinetics
• Modeling Ozonation in Bubble Contactors
• Ozone Rate Coefficient Determinations
• Ozonation of Tomato Wastewaters
• Ozonation of Distillery Wastewaters