Department of Civil and Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France.
Water Res. 2020 Oct 1;184:116171. doi: 10.1016/j.watres.2020.116171. Epub 2020 Jul 12.
In this study, a novel peroxymonosulfate (PMS) activation method, which combines a solid waste (i.e., red mud, RM) and a reducing agent (i.e., hydroxylamine, HA), for the oxidative degradation of fluoroquinolones (FQs; i.e., flumequine (FLU) and ciprofloxacin (CIP)) in hospital wastewater (HW) was developed. The addition of HA into the PMS/RM suspension significantly enhanced FLU removal, owing to its ability to enhance the Fe(III)/Fe(II) cycle on the RM surface. The results of the quenching experiments suggested the predominance of SO over OH in the PMS/RM/HA system. Moreover, owing to the greater reactivity between CIP and SO, CIP removal was more effective than FLU removal. Additionally, the liquid chromatography-mass spectroscopy (LC-MS) analysis revealed that the oxidation of CIP and FLU by PMS/RM/HA occurred via sequential and separate processes, involving ring cleavage, hydroxylation, decarbonylation, and defluorination. Surprisingly, the wastewater components exhibited contrasting effects on FLU removal in HW. Natural organic matter, nitrate and sulfate showed a slight impact on the removal performance of FLU, whereas chloride improved the oxidation extent. However, phosphate significantly inhibited the FLU removal because of its competitive binding at the RM surface and its scavenging effect towards SO. This inhibitory effect was overcome by increasing the PMS concentration and its sequential addition, thus guaranteeing successful mineralization of FLU in HW. These results show that the RM/HA system can be utilized to activate PMS for the removal of antibiotics in wastewater.
在这项研究中，开发了一种新颖的过一硫酸盐（PMS）活化方法，该方法将固体废物（即赤泥，RM）和还原剂（即羟胺，HA）结合起来，用于氧化降解医院废水中的氟喹诺酮类药物（FQs；即氟苯尼考（FLU）和环丙沙星（CIP））。HA 的加入显著增强了 PMS/RM 悬浮液中 FLU 的去除，这是由于其能够增强 RM 表面上的 Fe(III)/Fe(II)循环。猝灭实验的结果表明，在 PMS/RM/HA 体系中，SO 的优势大于 OH。此外，由于 CIP 和 SO 之间的反应性更强，因此 CIP 的去除比 FLU 的去除更有效。此外，液相色谱-质谱（LC-MS）分析表明，PMS/RM/HA 体系中 CIP 和 FLU 的氧化是通过顺序和单独的过程发生的，涉及环裂解、羟化、脱羰基和脱氟。令人惊讶的是，废水中的成分对 HW 中 FLU 的去除表现出相反的影响。天然有机物、硝酸盐和硫酸盐对 FLU 的去除性能影响不大，而氯化物则提高了氧化程度。然而，磷酸盐由于其在 RM 表面的竞争结合及其对 SO 的清除作用，显著抑制了 FLU 的去除。通过增加 PMS 浓度及其顺序添加，可以克服这种抑制作用，从而保证 HW 中 FLU 的成功矿化。这些结果表明，RM/HA 系统可用于激活 PMS 以去除废水中的抗生素。
