过乙酸(PAA)作为废水处理的替代氧化剂受到越来越多的关注。然而,用于PAA活化以产生反应性物种的现有工艺通常需要外部能量输入(例如,电和紫外线介导的活化)或催化剂(例如,Co2+),不可避免地增加处理成本或引入需要额外去除的潜在新污染物。在这项工作中,我们开发了一种无催化剂,两室生物电化学系统(BES)中的自我维持生物电化学方法,其中阴极电极使用由阳极外生产生的可再生生物电子原位激活PAA(例如,Geobacter)降解可生物降解的有机物(例如,乙酸)在阳极废水中。这种创新的BES-PAA技术在没有外部电压的情况下,在pH2(阳离子交换膜)和pH6(双极膜)下,在两小时内实现了2µM磺胺甲恶唑(SMX)的98%和81%的去除。机械研究,包括自由基猝灭,分子探针验证,电子自旋共振(ESR)实验,和密度泛函理论(DFT)计算,揭示SMX降解是由生物电子介导的PAAOO裂解产生的反应性物种驱动的,CH3C(O)OO·贡献68.1%,•OH为18.4%,CH3C(O)O·为9.4%,•OH和CH3C(O)O•的初始形成与PAA迅速反应生成CH3C(O)OO•。常见水成分的存在,如阴离子(例如,Cl-,NO3-,和H2PO4-)和腐殖酸(HA)显着阻碍了通过BES-PAA技术去除SMX,而CO32-和HCO3-离子的影响相对较小。此外,该研究调查了二级处理过的城市污水中存在的各种药物的去除,将去除效率的差异归因于CH3C(O)OO·的选择性作用。这项研究证明了一种新的PAA激活方法,在生态上是良性的,便宜,能够克服催化剂失活和二次污染问题。
Peracetic acid (PAA) has received increasing attention as an alternative oxidant for wastewater treatment. However, existing processes for PAA activation to generate reactive species typically require external energy input (e.g., electrically and UV-mediated activation) or catalysts (e.g., Co2+), inevitably increasing treatment costs or introducing potential new contaminants that necessitate additional removal. In this work, we developed a catalyst-free, self-sustaining bioelectrochemical approach within a two-chamber bioelectrochemical system (BES), where a cathode electrode in-situ activates PAA using renewable biogenic electrons generated by anodic exoelectrogens (e.g., Geobacter) degrading biodegradable organic matter (e.g., acetic acid) in wastewater at the anode. This innovative BES-PAA technique achieved 98 % and 81 % removal of 2 µM sulfamethoxazole (SMX) in two hours at pH 2 (cation exchange membrane) and pH 6 (bipolar membrane) using 100 μM PAA without external voltage. Mechanistic studies, including radical quenching, molecular probe validation, electron spin resonance (ESR) experiments, and density functional theory (DFT) calculations, revealed that SMX degradation was driven by reactive species generated via biogenic electron-mediated OO cleavage of PAA, with CH3C(O)OO• contributing 68.1 %, •OH of 18.4 %, and CH3C(O)O• of 9.4 %, where initial formation of •OH and CH3C(O)O• rapidly reacts with PAA to produce CH3C(O)OO•. The presence of common water constituents such as anions (e.g., Cl-, NO3-, and H2PO4-) and humic acid (HA) significantly hinders SMX removal via the BES-PAA technique, whereas CO32- and HCO3- ions have a comparatively minor impact. Additionally, the study investigated the removal of various pharmaceuticals present in secondary treated municipal wastewater, attributing differences in removal efficiency to the selective action of CH3C(O)OO•. This research demonstrates a novel PAA activation method that is ecologically benign, inexpensive, and capable of overcoming catalyst deactivation and secondary pollution issues.