Evaluation of Conventional and Novel Treatment Technologies for RO Reject

Grieco, PhD, PE Global Principal & Technology Leader – PFAS & Emerging Contaminants Drinking Water & Reuse Treating Water for PFAS with RO/NF Larger Flowrates  RO is often a consideration – expense and reject management Co-contaminants  Manage salinity or hardness Higher TOC  Adsorption competition with PFAS limits efficiency Surface waters  Seasonal variation  Implementing field pilot is encouraged 5 ©Jacobs 2024 NF / RO Performance for Terminal PFAS Light Gray – 75% recovery Dark Gray – 97% recovery Source: Closed-Circuit High-Pressure Membrane Systems for the Separation of Per and Polyfluoroalkyl Substances, Safulko, A. et. al., Membrane ©Jacobs 2024 Technology Conf 2022. PFAS, Flowrate, and Water Complexity Leachat Municipal RO Water e Wastewater Reject Quality Complexity Drinking Water PFAS Concentrati Flowrate or on Volume to Treat 7 ©Jacobs 2024 Technology List Potential Category Transfer Destructive Availability Current / Short- GAC / PAC term – Ion Exchange – Gel resin Effective & Practiced None Medium- – Macro-porous resin – Reverse Osmosis (RO) term – Nanofiltration (NF) Longterm – Specialty Adsorbents Maturing & – Fluoro-sorb (FS-200) None Demonstrated – Foam Fractionation – Jacobs direct – Regenerable Adsorbents experience – Electro-oxidation Developing – Speciality Adsorbents – Non-thermal plasma – CycloPure – Advanced Red/Ox – Oxyle ©Jacobs 2024 8 Adsorbents for PFAS Removal IX GAC FS  Activated carbon (GAC)  Ion exchange  Alternative adsorbents −CETCO Fluoro-sorb 10 ©Jacobs 2024 Bench-scale RO  Brackish water TFC membranes (Applied Membranes) −2.5” x 40” elements  Operated in reject recirculation mode −3.1 gpm feed flow −Batch mode to obtain target recovery (85% & 90%) −38% recovery (1.2 gpm) −37 to 46 psi  Loss in weight feed measurement 16 ©Jacobs 2024 Conclusions  RO is effective is removing PFAS from drinking water −RO reject is more complex due to higher concentrations  No “silver bullets” for PFAS in RO concentrate −Generally same technologies that we are applying for drinking water  All 4 media tested worked well (<MCL / ND) −No significant limitation of mass loading (Raw vs RO Concentrate) −Confirm projections (based on RSSCT) with field-scale piloting −Determine most feasible technology based on cost analysis (not included)  Application of SAFF is effective for RO Concentrate −Recommend using EPA 1633 or Modified 537.1 (too much interference for 533) −Required additional treatment or disposal of Foamate −Would be most relevant for application of destructive technologies −Confirm projections (based on bench-scale testing) with field-scale piloting  22 ©Jacobs 2024.