Synergistic activation of peroxymonosulfate and persulfate by ferrous ion and molybdenum disulfide for pollutant degradation: Theoretical and experimental studies. (February 2020)

• Record Type: Journal Article
• Authors: He, Dongqin; Cheng, Ying; Zeng, Yifeng; Luo, Hongwei; Luo, Kai; Li, Jun; Pan, Xiangliang; Barceló, Damià; Crittenden, John C.
• Is Part Of: Chemosphere. Volume 240(2020)
• Publication Date: 2020-02
• Subjects: Advanced oxidation processes -- Sulfate radicals -- Synergistic activation -- Peroxymonosulfate -- Persulfate; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.124979
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Activation of peroxymonosulfate (PMS) and persulfate (PS) by Fe 2+ is widely used for oxidizing organic pollutants. However, their application is limited by the slow conversion rate of Fe 3+ to Fe 2+ and the accumulation of Fe 3+ . Here, we introduce commercial molybdenum disulfide (MoS2 ) to promote the activation of PMS and PS by Fe 2+, and explore the mechanism of this promotion using experimental and theoretical methods. The Fe 2+ /PMS/MoS2 and Fe 2+ /PS/MoS2 systems achieved faster rate of PMS and PS conversion and also higher degradation efficiency toward pollutants. About 94.7% and 87.6% of rhodamine B (RhB) could be degraded in Fe 2+ /PMS/MoS2 (54 μM Fe 2+, 1 mM PMS) and Fe 2+ /PS/MoS2 (54 μM Fe 2+, 0.25 mM PS) system, respectively. MoS2 addition simultaneously promoted the Fe 3+ /Fe 2+ cycle, the PMS and PS conversion, and the RhB mineralization. As a co-catalyst, MoS2 exhibited excellent stability for eight successive cycles of use. The predominant oxidant was identified as SO4 − in Fe 2+ /PMS/MoS2 and Fe 2+ /PS/MoS2 systems. Theoretical calculations and a kinetic model were employed to evaluate the catalytic performance of the systems. These novel findings indicate that the combination of a commercially available MoS2 catalyst with a low dosage of Fe 2+ is a promising and effective approach for efficient activation of PMS and PS to produce SO4 − and OH. Highlights: Synergistic activation of PMS and PS by Fe 2+ and MoS2 was reported. MoS2 had a faster decomposition rate than Fe 2+ for activation of PMS and PS. The generation and intensity of SO4 − and OH radicals were determined. MoS2 addition promoted the Fe 3+ /Fe 2+ cycle and RhB mineralization. Economic analysis was performed by electrical energy per order (EE/O) approach.