300 Tons of Provect-IR Remediates Multi-Acre PCE Plume in Brazil

This site is a former small appliance manufacturing plant located in São Paulo, Brazil, that was contaminated due to previous business operations. Soil and groundwater were impacted with chlorinated volatile organic compounds (CVOCs), including tetrachloroethylene (PCE), trichloroethylene (TCE), cis-1,2-dichloroethene (cis-1,2 DCE), vinyl chloride (VC), and 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA). PCE was the most widespread and concentrated contaminant of interest in groundwater, exceeding concentrations of 200,000 µg/L. The hydrogeological model is complex for this site, with the vertical treatment zone being divided into four hydraulic layers with confining clay zones. The shallowest zone was considered most important for remediation due to the potential for vapor intrusion impacts.

The remediation plan developed by SGW Services (São Paulo, Brazil) included the combination of multiple technologies to remediate soil and groundwater across the 10,500 sq meter (113,000 sq ft) plume. In situ chemical reduction (ISCR) with Provect-IR® was utilized in the majority of the plume across multiple vertical hydraulic zones. The efficacy of Provect-IR® was first confirmed via bench testing, which was followed by field-scale pilot tests.

"The final remediation plan included 300 tons (600,000 lbs) of Provect-IR® that was injected via 537 direct push points ranging in depth from 4 to 17 meters (13 to 56 ft) below ground surface."

The pilot test results were utilized to develop the full-scale remediation plan. Provect-IR® is a site-specific blend of unique reagents combined into a single product that optimizes the in situ reductive dechlorination of chlorinated VOC contamination in both soil and groundwater. This technology works by promoting synergistic interactions between zero-valent iron (ZVI), hydrophilic, nutrient-rich organic carbon sources, chemical oxygen scavengers, vitamins, and mineral sources.

Additionally, Provect-IR® is the only ISCR reagent to simultaneously inhibit the production of methane during the requisite carbon fermentation process, which promotes more efficient use of the hydrogen donor while avoiding negative drawbacks associated with elevated methane.