Microelectrode Observatory for In Situ Monitoring of Metals Concentration and Mobility in Contaminated Sediments
ER-201128
Objective
The objective of this project is to demonstrate and validate the microelectrode geochemical observatory (MGO) for monitoring metals in contaminated sediments. The MGO has the capability to measure in situ metals concentrations in sediments, including simultaneous measurement of several redox-active metal species (e.g., cadmium and lead). Redox-active elements commonly encountered in sediments that are amenable to electrochemical detection include but are not limited to Fe(II), Fe(III), Hg(II), Cu(II), Mn(IV), Cd(II), Ni(II), Pb(II), Ag(II), As(III), As(V), Zn(II), and several sulfide species (e.g., sulfide, thiosulfate, and thiols).
Technology Description
The MGO consists of several (up to eight) individual solid-state electrochemical sensors that are able to be programmed to detect those metals of interest at a particular site. Each MGO includes solid-state microelectrode technology for metals detection with the monitoring of background geochemical parameters (temperature, conductivity, pH, and oxidation-reduction potential [ORP]) at several vertically stratified sampling points. Each observatory can be tailored to site-specific depth intervals with several microelectrodes spaced according to the sampling requirements, capturing pore water concentrations in the native sediments, cap layer, and the overlying water. Each probe is engineered within a cylindrical housing structure, approximately 4-in diameter, with the length determined by the site-specific requirements. This system is capable of nearly continuous monitoring of dissolved metals, including selectivity for speciation of certain metals, and promises to provide monitoring data to site managers to capture long-term trends.
Points of Contact
Principal Investigator
Dr. Nancy Ruiz
Naval Facilities Engineering and Expeditionary Warfare Center
Phone: 805-982-1155
Fax: 805-982-4304
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.