Formatted Title
Assessment of Environmental Footprints for Per- and Polyfluoroalkyl Substances (PFAS) Treatment Technologies for Liquids and Solids
Background/Objectives
Background/Objectives: Per- and polyfluoroalkyl substances (PFAS) treatment technology selection evaluates many factors before full-scale implementation. Along with cost and treatment efficacy, an important consideration is sustainability footprint. The low cleanup levels likely to be promulgated for PFAS will potentially require long-term/extensive treatment operations, making the environmental footprint even more significant over that duration. Understanding these impacts will provide additional information to be considered during remedy selection.
Approach/Activities
Approach/Activities. For this evaluation, two hypothetical scenarios were considered for treatment of PFAS-impacted liquids and solids/soils. Liquids: (1) 1,000-gallons of investigative derived waste (IDW) (e.g., decontamination water, well development water, sample purge water) stored in drums; (2) 50,000,000-gallons of water treated over a year during operation of groundwater pump and treat or water treatment plant. Solids/Soils: (1) Five 55-gallon drums of IDW soil from drill cuttings; (2) 10,000 cubic yards of impacted soil.
Over 30 vendors offering PFAS treatment technologies were contacted to provide implementation and operational data to estimate the greenhouse gas (GHG) footprint for each technology, addressing either one of both scenarios, as appropriate to the technology capabilities. These technologies included:
- Liquid sorption: granular activated carbon (both single use and with reactivation), ion exchange resin (both single use and regenerable), and custom sorbents (e.g., CETCO Fluoro-sorb)
- Liquid concentration/disposal/transfer: foam fractionation, flocculation, deep well injection
- Liquid destruction: supercritical water oxidation, hydrothermal alkaline treatment, electrochemical oxidation, electrolysis, non-thermal plasma, catalytic oxidation
- Soil treatment: soil washing, soil stabilization, disposal, thermal desorption.
For each, the elements of largest GHG impact were considered: production/transportation of treatment materials, waste handling/disposal, electrical requirements, and fuel requirements. The data received were compiled by technology providing a range of values for each.
Results/Lessons Learned
Results/Lessons Learned. This presentation will review the ranges of inputs received from the technology vendors, the methods and relevant assumptions utilized for the GHG evaluation, the limitations of the evaluation, and the results. Overall, it was determined that some of the largest contributors to the greenhouse gas emissions for treatment of PFAS are electricity usage and transport of materials and equipment. The discussion of results includes considerations for opportunities to reduce the overall footprints.