title: Effect of surfactants on the degradation of perfluorooctanoic acid (PFOA) by ultrasonic (US) treatment.
abstract: Perfluorooctanoic acid (C7F15COOH, PFOA) is an aqueous anionic surfactant and a persistent organic pollutant. It can be easily adsorbed onto the bubble-water interface and both mineralized and degraded by ultrasonic (US) cavitation at room temperature. The aim of this study is to investigate whether the effect of US on the degradation of PFOA in solution can be enhanced by the addition of surfactant. To achieve this aim, we first investigated the addition of a cationic (hexadecyl trimethyl ammonium bromide, CTAB), a nonionic (octyl phenol ethoxylate, TritonX-100), and an anionic (sodium dodecyl sulfate, SDS) surfactant. We found the addition of CTAB to have increased the degradation rate the most, followed by TritonX-100. SDS inhibited the degradation rate. We then conducted further experiments characterizing the removal efficiency of CTAB at varying surfactant concentrations and solution pHs. The removal efficiency of PFOA increased with CTAB concentration, with the efficiency reaching 79% after 120 min at 25°C with a 0.12 mM CTAB dose.
authors.affiliation: Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Road, Taipei 106, Taiwan, ROC.
authors.forename: Jo-Chen
authors.initials: JC
authors.lastname: Lin
authors.affiliation: School of Public Health, Taipei Medical University, 250, Wu-Hsing Street, Taipei 110, Taiwan, ROC.
authors.forename: Ching-Yao
authors.initials: CY
authors.lastname: Hu
authors.affiliation: Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Road, Taipei 106, Taiwan, ROC. Electronic address: sllo@ntu.edu.tw.
authors.forename: Shang-Lien
authors.initials: SL
authors.lastname: Lo
keywords: Critical micelle concentration; Hexadecyl trimethyl ammonium bromide; Perfluorooctanoic acid; Surfactants; Ultrasonic