Water Quality Monitor
PO Box 2980
College Station, TX 77841
Bernie B. Bernard (409-690-1711)
JSC -- NAS9-17945
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:
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.