Dr. David Major, Ph.D., BCES, is the Managing Director of Savron, a division of Geosyntec Consultants, Inc, and Associate Editor of Ground Water Monitoring and Remediation. He has helped develop and commercialize remediation technologies such as zero-valent iron (ZVI) permeable reactive barriers, molecular biomarkers, bioaugmentation cultures, and currently Savron’s smouldering-based combustion technology (STAR). Dr. Major has served on various national scientific advisory boards including the U.S. EPA Expert Panel on DNAPL Remediation (The DNAPL Remediation Challenge: Is There a Case for Source Depletion), and the U.S. National Research Council Committee on Geological and Geotechnical Engineering in the New Millennium. He has co-developed and taught ITRC course on monitored natural attenuation, accelerated bioremediation, and bioremediation of DNAPLs. He has received several awards including: University of Waterloo Faculty of Science Alumni of Honour Award (2007) in recognition of his professional accomplishments; Space Hall of Fame® (2007) for helping NASA commercialize “Products from Space Benefiting Planet Earth”; ASTM C.A. Hogentogler Award (2015) and ICE Telford Premium (2016) awards for papers on ground improvement technology. He can be reached at Savron, 130 Stone Road West, Guelph, Ontario, N1G3Z2, (519) 515-0860, and by email at firstname.lastname@example.org.
PFAS Destruction through Smoldering Combustion (STAR)
Smouldering is a flameless, exothermic oxidation reaction; charcoal in a BBQ is a typical example. Once initiated the smouldering reaction is self-sustaining and will propagate through the contaminated porous media without any additional external energy input. The U.S. Department of Defense (US DoD) Strategic Environmental Research and Development Program (SERDP) funded a study to evaluate the use of STAR to treat PFAS compounds in soils or investigation derived wastes (IDW). IDW includes drill soil cuttings and spent activated carbon (GAC) waste streams generated from treating water from well development and sampling.
Two types of smoulderable mixtures were tested; GAC loaded with PFAS and combined with sand, and a surrogate soil contaminated with PFAS and mixed with uncontaminated GAC. These mixtures smouldered at temperatures in excess of 900°C that destroyed the PFAS compounds. Post-treatment concentrations of PFAS in the remaining sand, soil, and ash were below detection limits (0.05 µg/kg). Initial emission analysis indicated that over 82% of the available fluorine was captured as HF with only small amounts of PFAS emitted which could be subsequently captured by activated carbon and treated. Results to date are promising, suggesting STAR may provide an effective remediation technique for PFAS-impacted soils and IDW.