Reduced metals are widely used to enhance remediation for a wide variety of contaminants in groundwater and soil/sediment. SiREM performs both microcosm and column studies for reduced metals applications using granular, nanoscale and micro-scale zero valent iron (ZVI), zero-valent magnesium, zinc and reduced iron minerals (e.g., siderite). Reduced metals microcosm studies are constructed using site groundwater and aquifer material to evaluate
- Design loading rates
- Effectiveness of specific reduced metals for remediation of contaminants
- Particle size comparison (granular versus micro or nanoscale)
- Use of bi-metallic particles (e.g., Mg-ZVI, Pd-ZVI)
- Comparison of emulsion formulations, sources or vendors
- Assessing biological/reduced metals interactions
ZVI Column Studies
ZVI continuous flow column studies are a critical step in the design process for permeable reactive barriers for groundwater remediation…
Permeable reactive barriers (PRBs) constructed with granular zero-valent iron (ZVI) are a proven remedial technology for treatment of chlorinated solvent groundwater plumes.
SiREM is the leading industry provider of granular ZVI column studies. These continuous flow column studies simulate the movement of groundwater through a PRB and typically last 1 to 2 months based on typical groundwater flow velocities. ZVI column studies can be used to evaluate key PRB design parameters including:
- Degradation half-lives for contaminants and assessment of breakdown products to rule out incomplete degradation etc.
- PRB residence time required to achieve site-specific remedial goals.
- PRB design thickness, determined using the residence time and the expected groundwater flow velocity.
- Treatment longevity. Geochemical gradients, which are indicators of mineral precipitation and reactivity loss, are used to assess the site-specific potential for passivation and fouling of ZVI.
- Product selection. ZVI column studies can be performed with several candidate ZVI materials, ZVI-sand mixtures, or dispersed ZVI zones simulating emplacement by injection techniques.