Plasma’s Role in Potable Reuse for PFAS Remediation

Taskforces, utilities, and manufacturers must adapt to contaminants of emerging concern. The most prevalent, persistent, and problematic of these pertinent pollutants are per- and polyfluoroalkyl substances (PFAS). Resource managers need reliable and resilient technologies that convert waste streams to value streams and satisfy regulations. Current state of practice for management of PFAS-laden soil and water is physical removal. These techniques, such as filtration and excavation, produce concentrate, hazardous waste, or leachate that must be properly disposed, which is costly and introduces long-term liabilities. The sustainability and versatility of existing techniques can be enhanced by complementing them with plasma. Unlike separation-based technologies, plasmas can breakdown the most refractory organics, including PFAS, without consumables. Plasmas can support sustainable, simultaneous, and synergistic treatment of PFAS and enable economically viable resource recovery, which is critical for water reuse. However, previous plasma-based purifiers could not scale. Purafide can provide customers with a pioneering platform technology that is effective, efficient, customizable, versatile, and—most importantly—scalable. Purafide’s proposed Plasma Water Reactor (PWR) uses close-packed water streams to amplify plasma propagation. This geometric approach minimizes energy consumption and maximizes the plasma-water interface, enabling scale to relevant commercial flow rates for the first time ever. For example, in an automotive industrial effluent, the PWR eliminated 97% of PFOS whereas the plasma jet removed just 83% of PFOS and required greater power. Plasmas have been studied in limited capacity in practical settings; particularly, there is no literature available on plasmas in potable reuse schemes. Customer discovery suggests Purafide’s value propositions are initially best suited in water reuse as a polishing technology (The final stage in treatment trains is disinfection, whose U.S. market is estimated at $1.4B). The Southern Nevada Water Authority, Great Lakes Water Authority, and Carollo Engineers have demonstrated their willingness to pilot the PWR. Deploying the PWR throughout potable reuse systems would significantly accelerate the transition of plasma-based technologies into the water industry. Each of the planned experiments performed by our multidisciplinary team is novel and promising—using variable pulsed power to tailor treatment, the PWR will be assessed on relevant water matrices including reverse osmosis concentrate, granular activated carbon and anion exchange effluents, and anion exchange regenerant. These investigations will help determine the best reuse applications for plasma and enable plasma performance to be modeled as a function of water quality. Collectively, this study has the potential to enhance the security, stability, and sustainability of water