Over half of all Americans and more than 95 percent of the rural population get their drinking water from an underground source. Although much work has been done to remediate and prevent groundwater contamination during the past three decades, a substantial effort is still needed to protect the increasing scare resource of safe drinking water. Monitoring dissolved oxygen (DO) is an important component for natural attenuation or bioremediation processes. A low cost, long-term stable and flow independent DO sensor that can be deployed for several years without drift is an ideal tool to monitor both natural attenuation and enhanced bioremediation processes and to assure investigators that the site remains free of contaminants. The objective of this proposal is to develop the next generation of oxygen sensors, which will overcome the problems associated with all currently available oxygen sensors. The design of the sensor proposed in this study will make it most suitable for long-term monitoring of dissolved oxygen in groundwater. Phase I will be conducting feasibility study and developing design requirements for the optical DO sensor. We will specifically address the following issues: 1) Sensor materials: synthesis of nano-crystalline zeolite-entrapped dye, dye/matrix deposition and casting of sensing element. 2) Dye matrix coupling with optics. 3) Detection electronics to overcome problems with variation of dye concentration and ambient light interference.
Commercial Applications and Other Benefits as described by the awardee: A commercial DO probe for long-term monitoring would support any activity for groundwater clean up and determine the extent of any contamination. It also support an activity for environmental monitoring where DO is the major concern. This sensor is vital to the control of any biological process within the water and could be used for a number of economic applications as well.
