A water quality monitor capable of measuring the conductivity, pH, organic content, and ammonia levels of reclaimed water in a regenerative life support system is required. The primary goal of this project was the definition of a system for accurately and precisely measuring total organic carbon (TOC) in the concentration range of 10 ppb to 1 ppm while minimizing the need for crew interaction and limiting the use of utilities such as gases, reagents, and power.Phase I consisted of a literature study and experiments to evaluate the analytical and mechanical aspects of a space-borne laboratory TOC analyzer. The experiments investigated a wet oxidation process for completely reacting organic compounds to and detection of CO2. The recommended method relies on temperature-promoted persulfate oxidation of organic compounds and a non-dispersive infrared detector (NDIR). Two innovations were applied to this approach: first, microwave energy was used to provide an instantaneous, as-needed heat source to promote oxidation and, second, a flow-through-trapping, reverse-flow-desorb scheme was applied in the NDIR. Other results were performance evaluations of prototype instrument hardware and a concept for a tiny optical bench IR detector that could replace the NDIR and give multiple results such as total hydrocarbon, total oxidizable nitrogen, and CO2 concentrations for air and water.Potential Commercial Application:An analyzer applying this technology could be applied in process monitoring in industries involved in manufacture of semiconductors, pharmaceuticals, and chemicals and in power generation and environmental control.STATUS: Phase I Only
