Research Project 4: PFAS Mineralization in Wastewater, Recycled Water, and Water Treatment Residuals

University Of Southern California, Los Angeles CA

Investigators

Abstract

PROJECT SUMMARY Research Project 4 (RP4) of the Southern California Superfund Research and Training Program for PFAS Assessment, Remediation and Prevention Center (ShARP) aims to develop practical technologies for destroying PFAS contaminants in water, in the context of wastewater reuse and groundwater recharge into aquifers contaminated by PFAS and other contaminants of Superfund relevance. Existing water treatment technologies (e.g., reverse-osmosis (RO), granular activated carbon (GAC), ion exchange) can remove PFAS from water effectively, but each of them relies on phase transfer or concentration, moving the waste stream from one environmental reservoir to another, rather than resolving PFAS contamination permanently. These treatment residuals may lead to downstream environmental contamination during disposal (e.g., discharge of RO brines into surface waters or thermal incineration of spent GAC, producing volatile PFAS combustion products which can enter the atmosphere). RP4 will develop practical means of removing PFAS from water in a manner that leads to their destruction, to avoid environmental PFAS contamination by treatment residuals. RP4 addresses SRP Mandate 4 to develop basic biological, chemical, and physical methods to reduce the amount and toxicity of hazardous substances through three specific aims. RP4 aims span biological, chemical, and thermal means for PFAS defluorination, all within the context of water reuse and groundwater recharge into PFAS-contaminated aquifers: Specific Aim (1): Bioremediation of PFAS in wastewater by treatment with anaerobic membrane bioreactors; Specific Aim (2): Advancing technology for chemical defluorination of PFAS in potable water, wastewater and water reuse brines; and Specific Aim (3): Improving PFAS degradation during thermal GAC regeneration, and monitoring of PFAS combustion products by gas phase mass spectrometry. The aims and outcomes of RP4 complement the efforts of all research projects and all cores in the Center. Data from RP4 will be transmitted to RP2 and RP3 to inform estimates of PFAS-associated human health risk under different scenarios. Any partially defluorinated transformation products identified by RP4 will be conveyed to RP1 and RP3 for toxicological evaluation and fate and transport property assessment. Any unique PFAS identified by non-target high resolution mass spectrometry in human serum samples collected by RP2 and environmental samples collected by RP3 will be evaluated for treatability by UV/ARP and incineration in RP4. Ultimately, the novel bioremediation, chemical and thermal defluorination advanced techniques developed in this project are expected to provide a sustainable and effective way to reduce PFAS exposure to drinking water contamination in the target communities and communities near Superfund and other hazardous sites.