Superfund Research Program
Microelectrodes for Environmental Monitoring
Project Leader: William D. Timmons
Grant Number: R43ES011891
Funding Period: Phase I: 2002-2005
Remediation of Superfund and other hazardous waste sites, particularly those using bioremediation techniques, requires the use of monitoring procedures to ensure that environmental conditions required for bioremediation of specific toxicants are present, and to verify that pollutant removal is occurring. In most cases, microscale in situ measurement of various constituents in aqueous and soil environments is essential for proper monitoring of environmental conditions at a specific location and to determine impacts of environmental stressors. Many of these measurements are currently made using electrodes of various types. Over the past decade, microelectrodes have been developed, but their fragility, susceptibility to electrical interference, and difficulty to manufacture and operate have limited their use to lab settings.
The first phase of this project aims to develop a suite of self-contained microelectrodes that can be used in the environment to monitor a variety of constituents in contaminated soils and sediments. The devices will contain a new type of microelectrode connected to a microelectronic circuit for amplifying, processing, and transmitting microelectrode signals. Procedures for production of an appropriate suite of microelectrodes will be developed, which will initially be for dissolved oxygen (amperometric), pH and ammonium (potentiometric) and ORP (conductimetric). The techniques will then be modified for phase two of the project to make a variety of other microelectrodes that can be used at Superfund sites to monitor the remediation progress, to verify that proper operating conditions are in place, and to ensure that the toxic chemicals are being effectively removed or detoxified.