Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chuo-Shan Rd., Taipei, 10673, Taiwan.
School of Public Health, Taipei Medical University, 250 Wu-Xing Street, Taipei, 11031, Taiwan.
Chemosphere. 2023 Mar;318:137932. doi: 10.1016/j.chemosphere.2023.137932. Epub 2023 Jan 20.
From an environmental perspective, approaching sustainability requires a fundamental conceptual shift from the wastewater treatment process toward integrated treatment systems that consider efficient and effective utilization. This study aims to investigate the effects of different surfactants on the removal of perfluorooctanoic acid (PFOA). We used cationic surfactants as both frothers and collectors in the electrocoagulation-flotation (ECF) method to improve the removal efficiency of PFOA. The results showed that, under a monopolar aluminum electrode and with an initial PFOA concentration of 0.25 mM, the ECF method with decyl-trimethyl-ammonium bromide (DTAB) was able to remove over 98% of PFOA within 10 min. Cationic surfactants with a similar linear alkyl chain shape to PFOA, but a longer chain length, are more effective at removing PFOA through the ECF process. The removal mechanism is thought to involve co-precipitation with aluminum hydroxides through Al-F bonding, co-flotation with cationic surfactants, and mixed micelle formation with cationic surfactants. The optimal conditions were tested in both synthetic and realistic wastewater matrices and produced similar results. It has the potential for real wastewater application. The energy yield (G) of ECF with 5 mM DTAB is 497 g·kWh, superior to other treatments, and is an extremely energy-effective method for separating PFOA from wastewater.
从环境角度来看，实现可持续性需要从废水处理过程向综合处理系统转变，以考虑高效和有效利用。本研究旨在研究不同表面活性剂对全氟辛酸（PFOA）去除的影响。我们在电絮凝浮选（ECF）方法中使用阳离子表面活性剂作为起泡剂和捕收剂，以提高 PFOA 的去除效率。结果表明，在单极铝电极下，初始 PFOA 浓度为 0.25mM 时，ECF 方法中使用十二烷基三甲基溴化铵（DTAB）可以在 10 分钟内去除超过 98%的 PFOA。与 PFOA 具有相似线性烷基链形状但链长更长的阳离子表面活性剂通过 ECF 过程更有效地去除 PFOA。去除机制被认为涉及通过 Al-F 键与铝氢氧化物共沉淀、与阳离子表面活性剂共浮选以及与阳离子表面活性剂形成混合胶束。在合成和实际废水基质中测试了最佳条件，结果相似。它具有实际废水应用的潜力。含 5mM DTAB 的 ECF 的能量产率（G）为 497g·kWh，优于其他处理方法，是一种从废水中分离 PFOA 的极其节能的方法。
