A novel strategy for enhancing heterogeneous Fenton degradation of dye wastewater using natural pyrite: Kinetics and mechanism. (June 2021)

• Record Type: Journal Article
• Authors: Wang, Chongqing; Sun, Ruirui; Huang, Rong; Cao, Yijun
• Is Part Of: Chemosphere. Volume 272(2021)
• Publication Date: 2021-06
• Subjects: Pyrite -- Heterogeneous Fenton -- Dye wastewater -- Catalytic mechanism; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.129883
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Hydrogen peroxide activation by pyrite for degradation of recalcitrant contaminants receives increasing attention. The improvement of catalytic efficiency of natural pyrite is still a challenging issue. This work provides a novel strategy of enhancing catalytic efficiency via pre-reaction between pyrite and hydrogen peroxide. Effects of process factors including pre-reaction time, hydrogen peroxide, solution pH and initial dye concentration were examined. Natural pyrite with low purity was characterized by Raman, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Reaction kinetic verifies tremendous improvement of the reaction rate through pre-reaction. Enhanced dye degradation is ascribed to hydroxyl radical production promoted by self-regulation of pH, Fe 2+ releasing and Fe 2+ /Fe 3+ cycle. The plausible mechanism was proposed based on multiple determinations. Dye degradation in different water matrix was efficiently obtained, as well as multicomponent dyes. Additionally, broad operation pH and good reusing performance make the developed process highly attractive for application. This work provides a solid step-forward of pyrite/hydrogen peroxide Fenton process for treatment of recalcitrant contaminants in wastewater. Highlights: H2 O2 activation by natural pyrite is enhanced via novel pre-reaction strategy. Catalytic reactions are revealed by multiple characterizations and determinations. Enhanced mechanism involves pH self-regulation, Fe 2+ /Fe 3+ cycle and ·OH creation. Potential application benefits from broad operation pH, water matrix insensitivity and good reusability.