Per‑ and polyfluoroalkyl substances (PFAS), are persistent pollutants found in both natural and engineered water systems due to their chemical stability, attributed to the strength of carbon‑fluorine (C-F) bonds. Traditional water treatment processes including granular activated carbon, ion‑exchange and reverse osmosis physically separate PFAS from water, but generate concentrated waste streams that require further disposal and treatment to avoid recontamination. Emerging destructive technologies such as electrochemical oxidation (EO) using boron doped diamond (BDD) anodes have demonstrated the ability to break C–F bonds, however complex matrices and the presence of co-contaminants can alter reaction pathways, suppress degradation, or lead to the formation of intermediate species. Under these conditions, constituents can participate in simultaneous secondary reactions that generate disinfection byproducts (DBPs).

This work tests the hypothesis that DBPs form during the EO of highly concentrated PFAS waste streams in complex aqueous environments. Using perfluorooctanoic acid (PFOA) as a model PFAS in various electrolyte matrices, EO degradation is quantified. Additionally, formed DBPs are captured via liquid-liquid Extraction and quantified with a gas chromatography with electron capture detector. By investigating links between PFAS degradation and DBP formation potential, this study highlights that destruction does not guarantee safe water, underscoring the need to assess the formation, fate, and toxicity of unintended byproducts in emerging PFAS treatment strategies.