Advanced Oxidation Treatment of Army Industrial Wastewaters: Propellant Wastewater.

Advanced Oxidation Processes AOPs are water treatment processes that generate hydroxyl OH radicals for destruction of organic contaminants using ozonelUV, hydrogen peroxideUV, or ozonehydrogen peroxide. These processes are important methods for Army wastewater treatment and contamination remediation. This project 1 analyzed information on AOPs for treatment of Army waste streams 2 developed predictive models for process development, optimization, and cost projection and 3 demonstrated on a laboratory scale AOP treatability of wastewater-containing DNT and ethanol. A linetic model was found most suitable for modeling the contaminant destruction process. For the DNT-containing wastewater, not only OH, but also a-hydroxyethyl radical HE produced by the action of hydroxyl radical on ethanol, were important for the destruction of DNT, depending on the oxygen concentration in solution. Techniques of kinetic analysis were used to determine the form of the rate equation for HE radical, and to evaluate the appropriate rate constants to yield the general model for reductive treatment. Combination with the OH-radical model gave a comprehensive model that correctly described systems in which both OH and HE processes occurred simultaneously. Discovery of the reductive reaction using the kinetic techniques led to a factor of 230 improvement in AOP treatment efficiency.