PFAS TREATMENT GOAL

Development of treatment process to treat 80,000 gallons of industrial trench water containing PFAS analytes reflected in Eurofins Lab Data (Job No. 680-261107-1) to below EPA MCLs for discharge to WWTP.

PFAS BENCH-SCALE PILOT TEST     

Test Columns:  3" diameter by 3 foot clear PVC columns with carbon bed depth of 20", 1 sand and 2 carbon filters.  

Pilot System Materials of Construction: PVC columns, DC diaphragm pump with Teflon free components, vinyl tubing, King flowmeter 1 to 10 gal/hr, Teflon free sealant compound, HDPE raw feed and treated water collection in 55-gal drums, brass valves and tubing connectors, stainless steel clamps.

Apparatus Cleaning Protocol: 150 oF hot water wash, 150 oF hot water scrubbing with brush with Alconox, triple rinse with hot water, triple rinse with distilled water.

     New vinyl tubing cleaned per Apparatus Cleaning Protocol.

     Scaling factor to simulate full-scale system.

Carbon Empty Bed Detention Time: (EBDT) for both carbon columns combined 17.26 min.

Flowrate: 0.071 gpm or 4.26 gallons per hour (gphr).

Pre-Run Pilot Media Preparation:

     Expose carbon to distilled water for 30 minutes, Back-flush carbon columns for 30 minutes to remove fines.

     Vibrate carbon columns to remove air pockets.

     Run raw water through pilot plant for 30 minutes prior to sample collection.

     Eight 5-gal pails of raw trench water equalized in one 55-gal HDPE drum for feed solution.

Sampling Protocol:

     Pilot Effluent Sample collected at 2 and 4 hours after raw water acclimation period, backpressure during pilot run 2.5 psi.

     Pilot Samples collected and placed in iced cooler and transported to Eurofins lab on same day of collection.

     Treated Pilot Effluent Water Eurofins lab sample results (see below)

PFAS FULL-SCALE SYSTEM DESIGN       

     Sand Filter: One 4 ft diameter by 6 ft high sand filter

     Carbon Filters: Two 4 ft diameter, carbon bed depth 6 ft, 75 cf of carbon/filter connected in series     

     Filter Column Specs: General Carbon HP-2000

     Carbon Specs: General Carbon GC 12 X 40PF

     Carbon Empty Bed Detention Time: (EBDT) combined for 2 columns in series: 17.26 minutes

     Sand Specs: Filtersil high-purity monocrystalline industrial quartz Grade 0.85, Effective Size (mm) 0.78, Uniformity Coefficient           1.47, Grade designation WG#1, Approx. Screen Size (inches) 0.030), bulk density 79-80 lb/cf loose, 83-85 lb/cf compacted.

     Design Treatment Parameters: 300 ng/l PFOS, 65 gpm, treat to less than (EPA MCLs)

PFAS FULL-SCALE SYSTEM PERFORMANCE  

     All analytes treated below MCL lab detection limits.

Full-Scale PFAS Treatment System