Grantee Research Project Results
Final Report: Ending Forever Chemicals: PFAS Adsorption and Decomposition
EPA Contract Number: 68HERC24C0009Title: Ending Forever Chemicals: PFAS Adsorption and Decomposition
Investigators: Navarathna, Chanaka
Small Business: Creekside Environmental Product
EPA Contact: Richards, April
Phase: I
Project Period: December 1, 2023 through May 30, 2024
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2024) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR)
Description:
Per- and polyfluoroalkyl substances (PFAS), also known as "forever chemicals," present a significant challenge due to their inherent toxicity and exceptional stability. This stability renders them persistent pollutants within the environment. The USGS has reported concerning levels of PFAS in nearly half of the nation's tap water. Developing efficient methods for the sorption and destruction of PFAS remains a significant technical hurdle. This research addresses this challenge by proposing a novel solution: the creation of low-cost adsorbents derived from rice husk and Douglas fir biochar. These biochars are designed to adsorb PFAS from various water sources, including drinking water, wastewater, and agricultural runoff. Additionally, our process focuses on the destruction of PFAS through a novel defluorination process. We have shown that near-complete destruction of fluorinated organic pollutants by solvated electron reduction occurs in Na or Ca/NH3 solutions at -50 to 30°C and Li/ethylene diamine solutions at elevated temperatures. These dehalogenations rapidly mineralize fluorides to their Na+ or Ca2+ chlorides or fluorides, while generating fully dehalogenated hydrocarbons.
Summary/Accomplishments (Outputs/Outcomes):
Significant progress has been made on all tasks. We have initiated the scale-up of biochar adsorbent manufacturing and anticipate commencing sales of the material by August 2024. Additionally, we have achieved a breakthrough in PFAS decomposition, demonstrating complete mineralization of PFAS compounds in two solvents: liquid ammonia and ethylenediamine. This discovery significantly enhances the commercial viability of our process. We foresee no impediments to commercialization following successful advanced development, contingent upon a successful Phase II proposal submission. Specifically, we used two biochar feedstocks: 1) waste product from syngas generated from Douglas fir and other wood, and 2) rice hulls. These adsorbents were used for PFAS adsorption from water with starting concentrations ranging from 100 ppt to 5 ppm. In these studies, we made significant strides in understanding the mechanisms and optimization of PFAS removal (dose, pH, time, concentration, temperature, competitive contaminants, column breakthrough, etc.) using batch and column studies. Another primary focus was to determine treatment parameters for solvated electron defluorination of PFAS-laden biochar in batch mode for the destruction of chlorinated compounds. A breakthrough was achieving complete decomposition (mineralization) of PFAS in two different solvents—liquid ammonia and ethylenediamine.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.