摘要：

We investigated the electrical response (0.11000 Hz)of reactive iron barriers to develop an electrical approach to long-term non-invasive monitoring of the performance of permeable reactive barriers (PRBs). Measurements on zero valent iron (F0)-sand columns were also conducted under the following conditions: (1) variable F0 surface area (0.1100% by volume F0) under constant electrolyte chemistry; (2) variable electrolyte activity (0.011 mol/liter), valence (mono trivalent), and pH under constant F0-sand composition; and (3) forced precipitation of iron hydroxides and iron carbonates on the F0 surface. Distinct electrical signatures exhibited that the performance of reactive iron in chlorinated solvent degradation was reduced over time. A field test at a well-characterized PRB was performed over a three-year period. The surface area of reactive iron exposed to contaminated groundwater exerted a primary control on PRB performance. Iron oxidation and precipitation onto the iron surface both reduced reactivity and were detrimental to PRB performance. Low frequency electrical measurements were sensitive to these changes in surface area and surface chemistry.

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