The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the...
Adventus Americas, Inc. (AAI), in cooperation with GfS mbH, Germany and IEG Technologies GmbH, Germany, successfully integrated their proprietary EHC and zero valent iron (ZVI) in situ chemical reduction technologies into microbiologically enhanced Ground Circulation Well (mGCW) systems.
The combined offering, trademarked as mGCW-R, is a reactive well technology for in situ treatment of soil and groundwater containing a wide range of contaminants, including perchlorate, pesticides, chlorinated solvents along with inorganic compounds (e.g. nitrate, sulfate) and heavy metals (mercury, arsenic and others). This integration of technologies provides significant benefits over conventional nanoscale iron applications proposed for environmental remediation purposes, and it promises to rapidly advance the successful field applications of these exciting nanotechnologies.
"One recognized limitation of employing nanoscale ZVI technology in situ is associated with a general inability to introduce and distribute these particles into the environment in a way which maintains their desired reactivity. In most cases, the nanoscale ZVI particles quickly aggregate and precipitate, which greatly reduces their efficacy (i.e., they do not actually migrate with groundwater flow),” said Dr. Jim Mueller, president of AAI. “This diminishes the value of applying expensive nanoscale reagents. Recognizing these limitations, we developed the mGCW-R technology in association with GfS, the world's leader in GCW based systems. We are confident that this unique combination of patented technologies offers site owners, regulators and consultants a new tool to facilitate effective remediation and accelerated closure of some challenging environmental issues".
The mGCW-R system treats soil and groundwater simultaneously. In most cases, no water is removed from the subsurface. By drawing groundwater from an aquifer formation through one screen section of a multi-screened well and discharging it through another, the mGCW-R creates an in situ vertical groundwater circulation cell that serves to distribute reagents, thus, creating an enlarged in situ reactive zone.
In addition, the action of groundwater circulation serves to bring contaminants into the reactive zone for continuous, in situ treatment. Given the unique ability to engineer, monitor and control critical operating parameters of the mGCW-R, the system, can effectively introduce and distribute various remedial catalysts such as, EHC and ZVI, and employ less expensive formulations of ZVI (1 to 5 micron range).
Dr. Eduard Alesi, president of GfS said, "The integration of AAI's EHC and ZVI technologies with our superior GCW systems provides a next generation of remedial strategies to address complex environmental challenges throughout the world. We are pleased to combine our knowledge gained from over 600 GCW applications worldwide with the power of the Adventus technologies—interest in applications for these newly integrated technologies is growing very rapidly."