Aqueous Phase Catalytic Oxidation of Organic Contaminants

最近，实验室表明，在120℃-160℃之间的温度下，在贵金属催化剂上使用氧气可以将水相中的各种有机污染物矿化。迄今为止的工作是支持载人空间探索的再生生命支持研究的结果。所研究的污染物是航天器上受污染的水流的典型污染物，如卫生水、湿度冷凝物和尿馏出物。在这些受污染的水域中，出现数量最多的有机化合物是低分子醇、羧酸和尿素。实验结果表明，溶解有机物浓度在10-50 mg/L范围内的混合污染物在推流反应器中单程深度氧化。与光催化、紫外光氧化和光电氧化等其他有机污染物去除方法的比较研究表明，多相催化在反应器尺寸和停留时间要求方面要有效得多。建议将这一技术扩展到污染地下水和地表水的有机污染物。在第一阶段的可行性论证之后，第二阶段计划将研究更广泛的污染物，评估过氧化氢和臭氧等替代氧化剂，努力实现催化剂活性的最大化，研究将催化剂失活的脆弱性降至最低，并优化反应堆设计和操作因素。

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 - 160Ý 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.