Superfund Research Program
Hydraulic Fracturing of Controlled Release Oxidants for Remediation of Low Permeability Zones
Project Leader: Alexis W. Carpenter
Grant Number: R44ES031461
Funding Period: Phase II: September 2019 - August 2020
- Program Links
The U.S. Environmental Protection Agency estimates that one out of every four Americans lives within three miles of a hazardous waste site. To meet the growing need for remediating these contaminated sites, the U.S. remediation market has been increasing steadily since 2009, averaging 2 - 3 percent increases per year. The global environmental remediation technology market is forecasted to expand to $80.5 billion in 2019. Remediation of contaminated sites can cost upwards of millions of dollars and can last for decades, especially in challenging geological settings such as low permeability (low-k) zones (e.g., clay and bedrock). Sites where contaminants are concentrated in low permeability zones are a particular industry headache as these areas can serve as sub-surface "source zones" providing slow release of contaminants into transmissive zones for decades or longer. Traditional, liquid-phase remediation injections that are successfully used in more permeable areas, when applied to low-k zones often result in only partial clean-up followed by chronic site management. Costly re-applications to address rebounding (increases in contaminant concentration following remediation) and tailings (persistent non-zero contaminant levels) are one of the biggest pain points for environmental engineers. These rebounding and tailings lead to increased liability, increased remediation cost, and long, drawn-out remediation schemes. AxNano, in collaboration with North Carolina A&T State University, has specially formulated its patented controlled release technology to address these persistent low-k zones. RemRx CRI, controlled release injectant, can be emplaced into low-k zones by hydraulic fracturing and provide sustained levels of ISCO reagents directly into the trapped contaminated area with one/few applications to address these issues of rebounding and tailings.
AxNano has established prototypes and preliminary studies to support a fast-track SBIR program. Phase I of the program supported the development of RemRx CRI through bench-scale testing of prototypes in low-k zone 2-D flow chambers and radius of influence estimation by computational modeling. Phase II aims to pilot-scale demonstrate manufacturing the Phase I-validated MVP and field test at two sites in the Piedmont Region. Field demonstrations will include comparison to straight oxidant performance. Data from pilot-scale demonstration and computational modeling will be used to design full-scale deployments. AxNano is designing a full-scale manufacturing process to support transition of the RemRx CRI technology to future large-scale deployment. This technology development program leverages a unique intellectual property position to develop this new RemRx family of products. The remediation and broader water/wastewater markets are complex, making market uptake of new remediation technologies difficult. However, controlled release ISCO agents are of strong interest. The AxNano team is committed to achieving the successful commercialization of this high-impact technology.