Granular zero-valent iron (ZVI) permeable reactive barriers (PRBs) are a proven remedial technology for treatment of chlorinated solvent groundwater plumes. Microscale zero-valent iron (mZVI), on its own or in combination with electron donors, can also be used in PRBs or grid type approaches to treat chlorinated solvent source zones and groundwater plumes. SiREM is the leading industry provider of ZVI column studies, a critical step in the design process for PRBs in the field. SiREM’s ZVI 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. Column studies are ideal for understanding the impact of groundwater flow on distribution of contaminants and amendments as well as the impact of geochemical gradients, for example redox, which can vary along the flow path. These factors can often have significant impacts on remediation processes and success.

ISCR Column studies are used to determine key design parameters including:

SiREM Technician Sampling ZVI Columns used to compare the effectiveness of different ZVI products and determine design parameters for a ZVI PRB

• Degradation Half-lives – for contaminants and assessment of breakdown products to rule out incomplete degradation and predict field performance.
• PRB Residence Time – required to achieve site-specific remedial goals.
• PRB Design Thickness – determined using the residence time required for treatment and the expected groundwater flow velocity.
• Treatment Longevity – to assess site-specific potential for passivation and fouling of ZVI or other amendments.
• Product Selection – compare several candidate ZVI materials, ZVI-sand mixtures, or dispersed ZVI zones simulating emplacement by injection techniques.
• Product Selection/Dosing – compare amendments for optimal performance/lowest cost.
• Amendment Sequencing – to simulate effectiveness of sequential application (e.g., EISB/ISCR).

SiREM’s technical experts are veterans in the design and operation of column studies and providing high quality reporting and scientifically grounded analysis to maximize the utility and interpretability of data.