Time domain reflectometry waveform analysis of cadmium, lead, and zinc in coaxial cells
- Bureau of Mines, Minneapolis, MN (United States). Twin Cities Research Center
Spatial and temporal variability of trace element fluxes within mineral related mining waste sites makes it difficult to obtain a quantitative understanding of the dynamics of trace element migration. Current methods of monitoring trace element migration within mining wastes involve point determinations including depth sampling and lysimetry. This study was conducted by the US Bureau of Mines to assess the application of time domain reflectometry (TDR) technology for monitoring spatial and temporal variations of trace elements in a contaminated medium. Purified, washed sand was poured into 5 cm inside-diameter seamless stainless steel tubes cut to 30 cm lengths and sealed at one end to form cells. Aqueous solutions of Cd, Pb, and Zn were added to separate cells. Each cell was oven dried at 105 C to remove the water, leaving a coaxial cell with a known level of trace element contamination. A 20 cm long stainless steel wave-guide consisting of two parallel rods attached to an SB1:1 was inserted into each coaxial cell and connected to a digital TDR (Tektronix Model 1502B) that was interfaced with a microcomputer to record the waveforms of each cell at settings of 0.5, 1.0, and 2.5 meters per division. Waveforms were analyzed and compared using the Northwestern University TDR Signature Analysis program (NUTSA). Results show that the reflected voltage (waveform) or characteristic signature varied depending on the trace element tested and it`s concentration. This suggests that TDR may be a useful technology to assess trace element contamination in various mineral related mine waste sites.
- OSTI ID:
- 215549
- Report Number(s):
- CONF-951139--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Landfill cover performance monitoring using time domain reflectometry
Time domain reflectometry development for use in geotechnical engineering