In-situ generation of multi-homogeneous/heterogeneous Fe-based Fenton catalysts toward rapid degradation of organic pollutants at near neutral pH. (April 2020)

• Record Type: Journal Article
• Authors: Li, Xuqing; Xiao, Bing; Wu, Meng; Wang, Lin; Chen, Rufen; Wei, Yu; Liu, Hui
• Is Part Of: Chemosphere. Volume 245(2020)
• Publication Date: 2020-04
• Subjects: In-situ generation -- Multi-homogeneous/heterogeneous catalyst -- Degradation -- Organic pollutant -- Mechanism; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.125663
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, an in-situ generated multi-homogeneous/heterogeneous Fe-based catalytic system was developed, which exhibited a high efficiency for the production of OH and rapid degradation of various organic pollutants in a near neutral pH range (5–8). The mechanism for the rapid decomposition of H2 O2 and the generation of OH were investigated in detail. The results indicated that, besides the introduced Fe 2+, the in-situ generated various iron species including Fe(OH) +, Fe(OH)2, Fe 3+, ferrihydrite (Fh), γ-FeOOH and α-FeOOH as well as Fe II /Fh, Fe II /γ-FeOOH and Fe II /α-FeOOH could simultaneously act as homogeneous and heterogeneous Fenton reaction catalysts. The dropwise addition manner of Fe 2+ greatly improved the catalytic efficiency of Fe 2+ ions in near neutral pH environment, while the in-situ generated nanosized Fh, γ-FeOOH and α-FeOOH could supply numerous active catalytic sites. After degradation, the ferrous ions could be transformed to various crystalline iron oxides by the catalytic phase transformation. This study presents a method towards the rational design of novel Fenton catalysts for wastewater treatment. Graphical abstract: An in-situ-generated multi-Fenton catalytic system was constructed, leading to the rapid degradation of organic pollutants at near neutral pH. Image 1 Highlights: A modified Fe 2+ Fenton reaction system was constructed. Pollutants with high concentration and different structures were degraded at near neutral pH. In-situ-formed multi-Fenton centers accelerated the decomposition of H2 O2 and generation of OH. After degradation, the added ferrous ions were transformed to hematite, goethite and magnetite.