Per- and polyfluoroalkyl substances (PFAS) in resource recovery: Transforming challenges into opportunities for sustainable nutrients and biosolids management

This study investigates the implications of PFAS (per- and poly-fluoroalkyl substances) on nutrient recovery and biosolids management at wastewater resource recovery facilities (WRRFs). PFAS are persistent contaminants that pose significant challenges to the sustainability of wastewater treatment. By addressing seven critical knowledge gaps — PFAS impact on nutrient recovery, identification and evaluation, behavior and transport, innovative treatment technologies, environmental and health impacts, workforce training, and a socio-techno-economic framework for PFAS management, we aimed to provide actionable strategies for improving future research priorities on PFAS mitigation efforts to promote WRRF sustainability. This was conducted by thoroughly synthesizing current scientific knowledge on our identified gaps; hence, we focused on the impact of PFAS through their behavior, fate, transport, monitoring, and identification methods in WRRF process streams toward PFAS remediation. Then, we provided several research directions and actionable proposal solutions for each knowledge gap. For example, new process configurations incorporating piloting technologies in the United States, which include incineration, pyrolysis, gasification, supercritical water oxidation, and mechanochemical milling, were proposed for PFAS-contaminated biosolids treatment to enhance WRRF circular economy. Collectively addressing these knowledge gaps with our proposed approaches provides tangible guidance in protecting public health and improving environmental sustainability in wastewater treatment.