Photocatalytic Oxidation and Reduction Chemistry and a New Process for Treatment of Pink Water and Related Contaminated Water

Photocatalytic treatment of pink water under oxidative conditions can mineralize TNT, HMX, and RDX but requires long residence times and a large power consumption. Photocatalytic treatment under reducing conditions, using EDTA, citric acid, glucose, and sodium formate, converts TNT to other substances. Power costs are significantly less than for the oxidative process. Biological treatment usingPhanerochaete crysosporium following EDTA reduction of pink water partially mineralized TNT. The degree of conversion of carbon to C02 depended on the duration of the photocatalytic pretreatment. Six hours of pretreatment produced 32% mineralization. This innovative new process for treating pink water is an effective method for reducing the level of TNT below the detection limit of 20 ppb. HMXand R DX are removed at a somewhat lower rate. Parties interested in learning more about this process may contact the authors of this report at NREL. Annual operating costs are estimated at $179,000 for a 150 gpm flow of pink water. The currently used carbon adsorption process costs $323,500. Capital costs are believed to be similar for both processes.