Enhance electrocoagulation-flotation (ECF) removal efficiency perfluorohexanoic acid (PFHxA) by adding surfactants

This research focuses on the application of electrocoagulation-flotation (ECF) in the removal of perfluorooctanoic acid (PFHxA), a prevalent short-chain perfluoroalkyl substance in semiconductor manufacturing, especially at concentrations of industrial wastewater levels. We explored the effectiveness of ECF, which employs sacrificial electrodes to create metal ions and bubbles for pollution extraction. The study particularly examines the role of various surfactants in augmenting PFHxA removal. We observed that at an initial PFHxA concentration of 1 mM, both anionic and cationic surfactants modestly increased removal efficiency, with limited impact from electrostatic repulsion. Significantly, at a higher concentration of 5.0 mM, cationic surfactants, notably DTAB with its short carbon chain, markedly enhanced PFHxA elimination. The superior performance of DTAB is attributed to its facilitation in Al(OH)3 crystal formation, promoting PFHxA adsorption, efficient micelle or bubble formation with PFHxA, and the stability of resulting flocs. Our findings underscore the efficacy of DTAB as a surfactant in ECF for high-concentration PFHxA scenarios, emphasizing the importance of surfactant and electrode material selection in optimizing PFAS treatment in wastewater systems. This study contributes valuable insights into refining PFAS remediation strategies in real industrial wastewater applications.