When a membrane is used to treat dye wastewater, dye molecules are continually concentrated at the membrane surface over time, resulting in a dramatic decrease in membrane flux. Aside from routine membrane cleaning, the pretreatment of dye wastewater to degrade organic pollutants into tiny molecules is a facile solution to the problem. In this study, the use of layered double hydroxide (LDH) to activate peroxymonosulfate (PMS) for efficient degradation of organic pollutant has been thoroughly investigated. We utilized a simple two-drop co-precipitation process to prepare CoFe-LDH. The transition metal components in CoFe-LDH effectively activate PMS to create oxidative free radicals, and the layered structure of LDH increases the number of active sites, and thereby considerably enhancing the reaction rate. It was found that the reaction process produced non-free and free radicals, including singlet oxygen (1O2), sulfate radicals (SO4•-), and hydroxyl radicals (•OH), with 1O2 being the dominant reactive species. Under the optimal conditions (pH 6.7, PMS dosage 0.2 g/L, catalyst loading 0.1 g/L), the degradation of Acid Red 27 dye in the CoFe-LDH/PMS system reached 96.7% within 15 min at an initial concentration of 200 mg/L. The CoFe-LDH/PMS system also exhibited strong resistance to inorganic ions and pH during the degradation of organic pollutants. This study presents a novel strategy for the synergistic treatment of dye wastewater with free and non-free radicals produced by LDH-activated PMS in a natural environment.
|Original language||English (US)|
|State||Published - Nov 29 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-12-01
Acknowledgements: This research was supported by Beijing Natural Science Foundation (8214056),National Natural Science Foundation of China (52100072), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA21021101), the Scientific Research Common Program of Beijing Municipal Commission of Education (KM202010017006, KM202110017008), Youth Innovation Promotion Association CAS (2020190) and the special fund of Beijing Key Laboratory of Clean Fuels and Efficient Catalytic Emission Reduction Technology.
ASJC Scopus subject areas
- Environmental Chemistry