Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia.
Australian Centre for Water and Environmental Biotechnology (ACWEB, formerly AWMC), The University of Queensland, St. Lucia, Queensland 4072, Australia.
J Hazard Mater. 2022 May 15;430:128408. doi: 10.1016/j.jhazmat.2022.128408. Epub 2022 Feb 2.
Reactive oxygen species play a critical role in degrading chemical or biological contaminants in advanced oxidation processes. However, it is still not clear whether conventional Fenton and photo-Fenton processes generate different reactive oxygen species, respectively. This study revealed the roles of reactive oxygen species (ROS) for simultaneous removal of antibiotic resistant bacteria (ARB) and recalcitrant micropollutant using three processes, i.e., conventional Fenton, photo-Fenton, and ethylenediamine-N, N'-disuccinic acid (EDDS) modified photo-Fenton. Both chemical scavengers and electron paramagnetic resonance spectroscopy confirmed the generation of various ROS and their contribution towards bacterial inactivation and micropollutant degradation. Results showed ARB and carbamazepine (CBZ) elimination efficiency in the order: EDDS modified photo-Fenton process > photo-Fenton process > Fenton process. The ARB detection limit (6-log ARB) was observed within 10 min at lower doses of 0.1 mM Fe, 0.2 mM EDDS, and 0.5 mM hydrogen peroxide (HO). With the same dose, it took longer (60 min) to remove CBZ, while 2.5 times higher HO dose (1.25 mM) removed around 99% of CBZ within 10 min treatment. The present study highlighted that the hydroxyl radical (HO) plays a dominant role, while singlet oxygen (O) and superoxide radical anion (O) exhibit moderate effects to remove the hazards. Our findings provide mechanistic insights into the role of various reactive oxygen species on degrading micropollutants and inactivating ARB.
活性氧在高级氧化过程中降解化学或生物污染物中起着关键作用。然而，目前尚不清楚传统的芬顿和光芬顿工艺分别产生不同的活性氧。本研究使用三种工艺，即传统芬顿、光芬顿和乙二胺二琥珀酸（EDDS）修饰的光芬顿，揭示了活性氧（ROS）在同时去除抗生素抗性细菌（ARB）和难降解微污染物中的作用。化学猝灭剂和电子顺磁共振波谱法均证实了各种 ROS 的生成及其对细菌失活和微污染物降解的贡献。结果表明，ARB 和卡马西平（CBZ）的去除效率顺序为：EDDS 修饰的光芬顿工艺>光芬顿工艺>Fenton 工艺。在较低剂量 0.1 mM Fe、0.2 mM EDDS 和 0.5 mM 过氧化氢（HO）下，10 分钟内即可观察到 ARB 的检测限（6 对数 ARB）。在相同剂量下，去除 CBZ 需要更长时间（60 分钟），而 2.5 倍高的 HO 剂量（1.25 mM）在 10 分钟处理内可去除约 99%的 CBZ。本研究强调了羟基自由基（HO）起主导作用，而单线态氧（O）和超氧自由基阴离子（O）则表现出适度的作用来去除危害。我们的研究结果为各种活性氧在降解微污染物和灭活 ARB 中的作用提供了机制上的见解。
