Phytostabilization of Mine Tailings in the Southwestern US: Plant-Soil-Microbe Interactions and Metal Speciation Dynamics
Mine tailings are among the most important sources of environmental metal contamination and they require novel remediation approaches. Since the form of a metal controls its bioavailability, experiments that probe changes in metal speciation in response to remediation schemes are needed to provide essential validation. In arid regions, mine tailings and associated contaminants are prone to wind-borne dispersion and water erosion. These problems are extensive and can persist for decades because impacted sites lack normal soil stabilization (e.g. establishment of a plant cover and subsurface organic matter accumulation).
Phytostabilization is the process of vegetating mine tailings with sufficient coverage to reduce wind and water erosion. It seeks to accumulate metals in the root zone rather than to extract them into above-ground biomass. To understanding how plant root-microbe associations affect metal speciation in mine tailings we are coupling macroscopic wet chemical methods with both bulk and spatially-resolved (EXAFS, FTIR, XRD) spectroscopic techniques.