Field Monitor to Measure Chromium and Cobalt in Subsurface Water and Soil

Ground and surface water contamination from anthropogenic sources is an important problem that must be monitored and remediated to protect the environment and human health. Dangerously high levels of chromium, cobalt and uranium have been reported in groundwater and soils at multiple Superfund sites from improper waste disposal or unintentional leeching. Contamination in subsurface environment is also a problem in industrialized areas, where waste from plating and other industries has been improperly disposed of into the groundwater. Monitoring these heavy metals is critical to public and environmental safety, particularly if contamination enters or is at risk of entering a water supply. The overall objective of the proposed program is to address subsurface water and soil monitoring needs by developing a portable, real-time electrochemical sensor for the measurement of toxic metal compounds (chromium, cobalt and uranium) in water and soil digestions/extracts, using a novel combination of an advanced electrode material with a micro-fabricated electrode geometry and a sensitive voltammetric detection algorithm for high sensitivity and low interference. Current monitoring methods require collection and shipment of samples to well-equipped laboratories for chemical analysis, which is time consuming and involves expensive instrumentation operated and maintained by trained personnel. A field-deployable monitor for determination of cobalt, chromium and uranium in water at ppb levels would avoid these problems. The Phase I program demonstrated the feasibility of Giners electrochemical technology by real-time detection of Cr(III), Cr(VI), and Co(II) at concentration levels down to 25 parts-per-billion (ppb) in control solutions samples. Extensive interference testing demonstrated the strength of the detection algorithms in the presence of common groundwater and soil constituents. While challenges remain, the Phase I program successfully validated Giners approach to create a compact device for measurement of multiple heavy metals in subsurface environments. The Phase II program will include sensor and instrument refinements and extensive field testing to study stability, reliability, and reproducibility of the portable monitoring system. Sample treatment and metal detection protocols will be developed for on-site testing of subsurface groundwater and soil extracts for chromium, cobalt, and uranium contamination at low ppb concentration levels. A prototype (alpha) monitor will be designed to advance the sensor to a state of technological-readiness for use in remediation and characterization at Superfund sites. Commercial Applications and Other Benefits: Potential commercial applications include at- home analysis of well water or groundwater and industrial self-monitoring of effluent. Potential government applications of the sensor will include water quality monitoring of public drinking water, groundwater, surface water, rivers and water quality monitoring of contaminated sites and industrial effluent for agencies such as DOE, DOD, and EPA.