Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Sci Total Environ. 2021 Dec 10;799:149506. doi: 10.1016/j.scitotenv.2021.149506. Epub 2021 Aug 5.
Iron oxychloride (FeOCl) is a known effective iron-based catalyst and has been used in advanced oxidation processes (AOPs). This study intends to achieve more facile free radicals generation from peroxymonosulfate (PMS) activation by exploring the Fe(III)/Fe(II) cycle of FeOCl in the presence of hydroxylamine (HA). With 0.2 g/L FeOCl, 1.5 mM PMS, and 1 mM HA, the PMS/FeOCl/HA system could effectively achieve 98.88% of the oxidative degradation of 5 mg/L ciprofloxacin (CIP) in 15 min and quickly inactivate 99.99% of E. coli (10 CFU/mL) in 5 min at near-neutral pH. HA played an important role in promoting the Fe(III)/Fe(II) cycle, thereby greatly improving the oxidation activity of the system. The reactive oxygen species (ROS) such as HO, SO and O were identified as the dominated free radicals produced in the system. The intermediate products of CIP detected by liquid chromatograph-mass spectrometer (LC-MS) and three possible degradation pathways of CIP were proposed. The presence of common anions in the PMS/FeOCl/HA system, including HCO, Cl, SO, and NO, enhanced the degradation efficiency of CIP to varying degrees at the concentrations of 10 mM. Moreover, FeOCl maintained a high degradation capability for CIP after several recycles. This work offers a new promising means of catalyzing the PMS-based AOPs in the degradation of refractory organics.
氧化铁氯（FeOCl）是一种已知的有效铁基催化剂，已被用于高级氧化工艺（AOPs）。本研究旨在通过探索羟基胺（HA）存在下 FeOCl 的 Fe(III)/Fe(II)循环，实现更易从过一硫酸盐（PMS）中产生自由基。在 0.2 g/L FeOCl、1.5 mM PMS 和 1 mM HA 的条件下，PMS/FeOCl/HA 体系能够在 15 分钟内有效实现 5 mg/L 环丙沙星（CIP）的 98.88%氧化降解，在近中性 pH 下 5 分钟内迅速灭活 99.99%的大肠杆菌（10 CFU/mL）。HA 在促进 Fe(III)/Fe(II)循环方面发挥了重要作用，从而极大地提高了体系的氧化活性。该体系中产生的主要自由基为 HO、SO 和 O 等活性氧物质（ROS）。通过液相色谱-质谱联用仪（LC-MS）检测到 CIP 的中间产物，并提出了 CIP 的三种可能的降解途径。在 PMS/FeOCl/HA 体系中，当常见阴离子（HCO、Cl、SO 和 NO）的浓度为 10 mM 时，不同程度地增强了 CIP 的降解效率。此外，FeOCl 在多次循环后仍保持对 CIP 的高降解能力。本研究为催化基于 PMS 的 AOPs 降解难降解有机物提供了一种新的有前途的方法。
