Recently it has been shown in the laboratory that various organic contaminants can be mineralized in the aqueous phase using dioxygen over noble metal catalysts at temperatures between 120o - 160Ã C. The work to date has been an outgrowth of regenerative life support research funded in support of manned space exploration. Contaminants studied have been those typical of contaminated water streams aboard spacecraft such as hygiene waters, humidity condensates, and urine distillates. The organic compounds occurring in highest quantity in these contaminated waters are low molecular weight alcohols, carboxylic acids, and urea. The experimental results have indicated deep oxidation of mixed contaminant streams containing dissolved organic compounds at concentrations between 10 - 50 mg/L in a single pass through a plug flow reactor. Studies comparing this technique with other methods of organic contaminant reduction such as photocatalysis, UV oxidation, and photoelectric oxidation have shown heterogeneous catalysis to be vastly more effective in terms of reactor size and residence time requirements. The extension of this technique to organic contaminants which commonly pollute ground and surface waters is proposed. Following demonstration of feasibility in Phase I, the Phase II program will study a wider range of contaminants, evaluate alternative oxidants such as hydrogen peroxide and ozone, work toward maximization of catalyst activity, investigate minimization of vulnerability to catalyst deactivation, and optimize reactor design and operational factors.
