Detection and Measurement of Explosives in Groundwater Using In Situ Electrochemical Sensors

摘要

The results of this study demonstrate that remotely-deployable submersible sensors are capable of monitoring explosive compounds both temporally and spatially in groundwater and can be more cost effective than conventional sampling and analysis. Such new remote-sensing capability can bring significant changes to the way in which nitro-based explosives are monitored. At this time, this technology can be deployed in standard groundwater wells that are 1.5 inches or greater in diameter. Future modification of the sensor probe could decrease the probe size to less than 3/4 inch to accommodate installation with minimally invasive direct-push technologies, ml such as cone penetrometer or GeoProbe system. Furthermore, the sensor measurement frequency can be easily changed from a remote location, enabling the investigator to tailor the measurement cycle to the speed at which the parameter in question is or may be changing. During the course of this SERDP SEED project, various working electrode materials and voltammetric waveforms were compared, and relevant experimental parameters were optimized. Based on initial testing we developed a submersible electrochemical probe, using a carbon-fiber electrode assembly, connected to a 50-foot-long shielded cable, for the real-time monitoring of nitro-organic explosives in natural water. The facile reduction of the nitro moiety group allowed convenient and rapid square-wave voltammetric measurements of trace levels of nitroaromatic explosives (TNT, TNB, and Tetryl) down to levels of 50 to 100 pb. A newly developed SERDP, SERDP Collection, groundwater, remote sensing, electrochemical detection, nitroaromatic explosives, nitroamine explosives.