EHC® is composed of controlled-release carbon, zero valent iron (ZVI) particles and nutrients used for stimulating in situ chemical reduction (ISCR) of otherwise persistent organic compounds in groundwater.
Following placement of EHC® into the subsurface environment, a number of physical, chemical and microbiological processes combine to create very strong reducing conditions that stimulate rapid and complete dechlorination of organic solvents and other recalcitrant compounds (e.g., explosives and organochlorine pesticides).
- Stimulation of both abiotic and biotic reductive dechlorination
- Demonstrated longevity of 4-5 years in field conditions
- Combined approach minimizes the production of problematic daughter products, such as DCE and VC
- ZVI corrosion (alkaline) and fermenting carbon (acidic) are balanced producing circumneutral pHs in contrast to either alone
- Non-hazardous and safe to handle
- Chlorinated solvents
- Energetic compounds
- Most pesticides
- Nitrate compounds
- Direct push injection
- Hydraulic fracturing
- Pneumatic fracturing
- Permeable reactive barriers
IN SITU CHEMICAL REDUCTION
In situ chemical reduction (ISCR) is the combination of abiotic chemical reduction, using zero valent iron(ZVI) and/or reduced minerals (magnetite, pyrite), coupled with anaerobic bioremediation for the effective treatment of chlorinated solvents, pesticides, and energetics. Physical, chemical, and biological processes combine to create an extremely reduced environment that stimulates chemical and microbiological dechlorination of otherwise persistent compounds.
Commercial sources of fermentable carbon will increase the activity of hydrogen-utilizing microbes. However, EHC® contains zero-valent iron, which enables in situ chemical reduction reactions (ISCR).
EHC® Reagent is a combination of controlled-release carbon and zero-valent iron (ZVI) particles designed to stimulate reductive dechlorination of otherwise persistent organic compounds in groundwater. EHC® is specially formulated for easy injection into the subsurface.
Extensive bench testing of EHC® for the treatment of 1,2 DCA has confirmed its superior efficacy compared to ZVI alone.
Technical Overview and White Papers
An overview of the different properties, mechanisms, and key attributes of our various reductive technologies.
Using US EPA criteria, Maul Foster & Alongi, Inc. reviewed four potential green remediation technologies (EHC® Reagent, emulsified oil, electrical resistive heating, and pump & treat).
EHC® application guides
Guidelines for EHC® slurry preparation and backfill, PRB, injection applications.
Baselines sampling recommendations for critical and non-critical parameters prior to the injection of EHC® Reagent.
Several core examination methods which could be used to evaluate reagent placement after injection.
Josephine Molin shares lessons learned from a number of EHC® injection projects where subsurface distribution validation has been performed. She shows the different methods used to verify ROI and observations in different lithologies, as well as about recommended injection equipment and approaches to limit surface formation during injection at difficult sites.
This presentation will introduce biological and chemical processes in situ, make field comparisons between the biotic approach (ERD) and the ISCR approach, and show how ISCR enhances biological processes in sulfate-rich aquifers.
We explain the physical, chemical, and microbiological processes promoted by MetaFix® and EHC® Reagents and how they work in the removal of soluble heavy metals, focusing on arsenic, chromium, lead, and mercury. The potential for simultaneous removal of soluble heavy metals and degradation of chlorinated solvents will also be discussed.
Brianna Desjardins and Brant Smith discuss the laboratory-scale tests our Environmental Solutions Laboratory typically performs on EHC® Reagent, ELS™ Microemulsion, KLOZUR® persulfate, MetaFix® Reagent, and hydrogen peroxide that are used to successfully implement remediation technologies.
Evonik’s laboratory created the KLOZUR® field test kit to provide a quick and reliable measurement of persulfate in the field.
There are two different kits available, depending on the activation method used. Each kit is capable of running ten tests and has a measurement range of 1g/L to 100g/L, with a theoretical accuracy of ±1g/L and ±2g/L respectively.