Destruction of Per- and Polyfluoroalkyl Substances (PFAS) with Advanced Reduction Processes (ARPs): A Critical Review
Junkui Cui1, Panpan Gao1,2, Yang Deng1
1Department of Earth and Environmental Studies, Montclair State University, Montclair, New Jersey 07043, United States.
Environmental Science & Technology
|March 13, 2020
Summary
Advanced reduction processes effectively destroy persistent per- and polyfluoroalkyl substances (PFAS) in water using hydrated electrons (eaq-). This review details PFAS destruction mechanisms and factors influencing efficiency for practical water treatment applications.
Area of Science:
- Environmental Chemistry
- Water Treatment Technologies
- Advanced Oxidation Processes
Background:
- Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants.
- Conventional water treatment methods are often ineffective for PFAS removal.
- Advanced reduction processes (ARPs) offer a promising alternative for PFAS destruction.
Purpose of the Study:
- To critically review the mechanisms and performance of reductive destruction of PFAS using hydrated electrons (eaq-).
- To overview the generation of eaq- in ARP systems like UV/sulfite and UV/iodide.
- To identify research needs for practical PFAS control in water industries.
Main Methods:
- Literature review of advanced reduction processes for PFAS destruction.
- Analysis of PFAS degradation mechanisms based on chemical structure and head groups.
- Evaluation of factors influencing PFAS degradation and defluorination efficiencies.
Main Results:
- Degradation pathways of various PFAS (PFOA, PFOS, PFCAs, PFSAs) are heavily influenced by their head groups and, for some, fluoroalkyl chain length.
- Hydrated electrons (eaq-) generated in ARPs are key to PFAS destruction.
- Solution chemistry (pH, dissolved oxygen, humic acid, nitrate) and operating factors (solute dose, temperature) significantly impact PFAS degradation and defluorination.
Conclusions:
- ARPs, particularly UV/sulfite and UV/iodide systems, show significant potential for PFAS destruction via eaq-.
- Understanding degradation mechanisms and influencing factors is crucial for optimizing PFAS removal.
- Further research is needed to translate these findings into effective industrial water treatment strategies.
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