(71a) Treatment and Color Removal of Wastewaters Using Wet Air Oxidation

Wet air oxidation (WAO) is a technology used to treat high strength wastewaters that typically have a chemical oxygen demand of 10,000 mg/L to 500,000 mg/L. These wastewaters typically contain compounds that produce a highly colored wastewater. Often, this color cannot be removed by conventional biological processes. In wet air oxidation, high temperatures (125 - 350 °C) and high pressures (300 ? 4,500 PSI) are used for the treatment of the wastewater. During this process, the complex chemicals in the wastewater are broken down into a biodegradable effluent, consisting mostly of small chained organic acids and carbon dioxide. By breaking down the complex chemicals in wet air oxidation, not only is the chemical oxygen demand greatly reduced, but most of the color is removed as well. The results from bench scale shaking autoclave testing of several highly colored wastewaters will be discussed.