Date
Monday, September 9, 2024
Time
11:30 AM - 12:00 PM
Location Name
M103
Name
Effective PFAS Removal and Waste Reduction using a Novel Micro-adsorbent and Separations Technology
Track
Drinking Water Quality
Description

Adsorptive media like granular activated carbon (GAC) and anion exchange resins (AIX) are currently the most practical and widespread methods to remove PFAS. Reverse osmosis (RO) and nanofiltration (NF) membranes can achieve exceptional PFAS removal, but are limited by higher capital and operational costs while producing significant waste streams that must also undergo treatment before disposal. Micro-adsorbents (MA) represent a special class of PFAS separation technologies which are designed to achieve high unit removal capabilities due to their exceptionally small size. The finest adsorbents can provide external surface areas several orders of magnitude greater than GAC and AIX per equivalent mass. A novel treatment system is presented which uses an efficient micro-adsorbent in a concentrated slurry to achieve high PFAS removals while sustaining hydraulic throughput. A specially designed separations technology retains the sorbent slurry at concentrations of 5,000 to 50,000 mg/L while producing particulate-free effluent. An integrated waste reduction technique produces very low waste volumes. The technology has been demonstrated in various matrices including surface water, groundwater and RO concentrate streams. Contaminated surface water PFOA and PFOS concentrations were reduced from 3,500 and 250 ng/L, respectively to less than 4 ng/L each. A combined 40 ng/L target for UCMR3 compounds (PFOA, PFOS, PFNA, PFHxS, PFHpA and PFBS) was achieved from a 5,000 ng/L influent. The system also shown that it could meet the US EPA’s proposed 1.0 Hazard Index for PFOA, PFOS, PFNA, PFHxS, PFBS and GenX. The micro-adsorbent and separations technology was able to achieve these levels with comparative sorbent quantities less than both GAC and AIX technologies.