Demonstration of Smoldering Combustion Treatment of PFAS-impacted Investigation-Derived Waste
Dr. David W. Major | Geosyntec Consultants
The primary research objective of the work is to demonstrate proof‐of‐concept for the use of smoldering combustion (SC) to treat investigation‐derived waste (IDW ‐ both liquid and solid) generated during investigation of per‐ and polyfluoroalkyl substance (PFAS) impacted sites. Two “value‐added” secondary objectives of the project (that will be achieved within the budget and testing program for the primary objective) are:
- To demonstrate proof‐of‐concept for the simultaneous treatment of PFAS‐impacted IDW and PFAS‐impacted activated carbon (GAC) historically generated during pump‐and‐treat management of plumes at PFAS sites, or generated during past management of IDW at PFAS sites, and
- To demonstrate that SC can effectively treat PFAS‐impacted soil at a much larger scale than that of IDW.
This project will use SC to destroy PFAS contained in solid and liquid IDW. Smoldering is a flameless form of combustion that occurs on the surface of a condensed (i.e., solid or liquid‐phase) fuel, converting organic material into primarily heat, carbon dioxide, and water. Laboratory testing will investigate the effectiveness of the process to destroy PFAS bound to soil and drilling waste. The primary matrices of interest are PFAS‐impacted waste soil or drilling waste which will be amended with a fuel such as charcoal, rubber, or GAC. PFAS‐impacted liquid IDW will also be treated with the approach, either through direct addition of the liquid to the solid waste prior to smoldering, or through a pre‐treatment step that binds the PFAS onto GAC, which then becomes the fuel for the smoldering of the solid waste. The primary objective will be to determine the extent and repeatability of remediation of the solid matrix (soil/ash) by SC with additional investigation of the emissions to consider the completeness of destruction of PFAS. All testing will be performed at the bench‐scale in reactors specifically designed (and proven) for testing SC.