Chlorinated solvent remediation is one of the highest priorities within the environmental industry. Reductive dechlorination is an effective method for degrading PCE, TCE, and other solvents (i.e. TCA, PCP, etc.) in groundwater aquifers and DNAPL zones. More information about the science behind anaerobic reductive dechlorination processes is provided here.

Reductive Dechlorination
Using the ISD™ System
While many dechlorination products are available today (sodium lactate, molasses, edible oils, etc.), the lack of effective application and delivery methods has often provided marginal results and/or extended remediation timeframes. Because of this, ETEC developed a series of automated delivery systems that accelerate in situ dechlorination rates and ensure complete dechlorination on a site-wide basis. These systems have allowed our clients to successfully complete numerous solvent remediation projects.

 
The ISD™ Process
Extracted groundwater is amended with a soluble substrate and nutrients by our ISD™ equipment platform, which then injects this treatment water back into the subsurface. This consistent recirculation of carbon-rich, nutrient-rich treatment water satisfies several critical requirements of reductive dechlorination, including:
 

onstant delivery of a readily-degradable carbon source to reduce native terminal electron acceptor mass and promote highly reductive conditions (i.e. sulfate-reducing or methanogenic) that encourage reductive dechlorination across a large plume area

  • Constant delivery of a readily-degradable carbon source to reduce native terminal electron acceptor mass and promote highly reductive conditions (i.e. sulfate-reducing or methanogenic) that encourage reductive dechlorination across a large plume area
  • Continuous movement of the injected treatment water through the contaminated soil and groundwater for optimum contact with dissolved and adsorbed chlorinated solvent constituents (PCE, TCE, DCE, etc.)
  • Hydraulic plume control and the simultaneous production of localized groundwater gradients that deliver amended treatment water to specific zones within a plume area
  • Explosive microbial growth within the pore space. After discontinuing groundwater circulation, this biomass will begin to “rot”, providing a long-term substrate to support ongoing dechlorination. Site data has shown continued dechlorination for up to 24 months following cessation of groundwater recirculation

After discontinuing groundwater circulation, this biomass will begin to “rot”, providing a long-term substrate to support ongoing dechlorination. Site data has shown continued dechlorination for up to 24 months following cessation of groundwater recirculation. More information on the key aspects of our approach to reductive dechlorination is provided here.