APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Bin Zhang,Shuangqing Xia,Zhenyi Wang,Wenqian Li,Boda Li,Haochen Zhang,Yanjun Xin,Kai Wu,Jun Ma,Xu He
Permanganate [Mn(VII)] needs to be activated to improve its reactivity towards refractory organic contaminants in practice. Herein, visible light (VL) and graphitic carbon nitride (g-C 3 N 4 ) were introduced to enhance the activation of Mn(VII) for the first time. Sulfamethoxazole (SMX) can be degraded effectively by VL/Mn(VII)/g-C 3 N 4 system in neutral and alkaline environments. Different from conventional Mn(VII) activation and photocatalytic processes, the performance of VL/Mn(VII)/g-C 3 N 4 system in various real water samples was superior than Milli-Q water. Mn(V) was found to be the dominant active species responsible for SMX degradation. Photo-induced electron (e cb – ) of g-C 3 N 4 under VL irradiation was proved to be the initiator of Mn(VII) activation. Density functional theory calculations revealed the strong affinity of g-C 3 N 4 for Mn(VII), which can resist the interference of water substrates on the Mn(VII) activation process by photo-induced e cb – . This work deepens the understanding of reactive manganese intermediates in the Mn(VII) activation system.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Chao Liu,Chaojie Wang,Bingxu Chen,Haitao Lu,Wei Ding,Hong Li
Conventional manganese(II) (Mn(II))-activated sulfite (S(IV)) systems remain constrained by slow reaction kinetics and inefficient Mn redox cycling, limiting their application in water treatment. Although non-radical pathways have been reported in certain metal/S(IV) systems, the role of high-valent Mn species remains unresolved. To address this knowledge gap, this study engineered a Mn-based metal-organic framework (Mn-MOF, denoted MM) featuring unsaturated Mn(II)−OH sites to achieve efficient S(IV) activation and redirect the oxidation process toward a non-radical route. Arsenite (As(III)) was employed as a model contaminant to systematically evaluate the MM/S(IV) system through kinetic analysis, reactive species identification, and surface characterization. The MM/S(IV) system enabled rapid As(III) oxidation (99.3% within 5 min, 0.64 min −1 ) at pH 7.4. The catalyst exhibited excellent stability during sequential operation (0.04% Mn leaching) and could be nearly fully regenerated. Mechanistic investigation revealed an interfacial pathway initiated by an O 2 -assisted, ligand-bridged electron transfer that yielded SO 3 •− /SO 5 •− . SO 5 •− subsequently oxidized Mn(II) to Mn(III), which then underwent two-electron oxidation by HSO 5 − to form Mn(V) as the dominant oxidant. This work demonstrates how MOF coordination engineering can redirect S(IV) activation toward a non-radical Mn(V)-mediated route, advancing the design of metal-centered oxidation systems for water remediation.
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DOI
高影响因子
ENERGY & FUELS
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2019
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IF 3.021
Jialin Meng,Yufeng Duan,Peng Hu,Yifan Xu,Xinze Geng,Ting Yao,Shaojun Ren,Hongqi Wei
A series of Mn–V–W/TiO2 (Mn–VWT) catalysts were synthesized by the impregnation method and calcinated at different temperatures (300–600 °C). To explore the effects of the reaction temperature, SO2, and H2O on the simultaneous removal performance of elemental mercury (Hg0) and NO, Mn–VWT were investigated by a fixed-bed reaction system. Various techniques (scanning electron microscopy, Brunauer–Emmett–Teller, X-ray diffraction, H2-temperature-programmed reduction, NH3-temperature-programmed desorption, and X-ray photoelectron spectroscopy) were utilized to characterize the samples. The results showed that the catalytic activity of Mn–VWT first increased and then decreased with the increasing calcination temperature. The removal efficiency of Hg0 and NO still had good performance even in low reaction temperature (200 °C), achieving 100 and 82%, respectively. Mn–VWT-400 had the best simultaneous removal performance because of the highest content of the Mn4+, V4+, and chemisorbed oxygen Oα and the best reductive activity at low temperature. Furthermore, SO2 irreversibly inhibited Hg0 and NO removal ability due to the sulfate and sulfite generation on the surface of Mn–VWT-400. Especially, the inhibition effect was more serious if SO2 and H2O coexisted because the rate of sulfate/sulfite was higher than that of the former. In addition, with the increase in reaction temperature, the effect of SO2 and H2O on the removal of Hg0 and NO over Mn–VWT was gradually reduced.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Lijun Niu,Lili An,Kaiting Zhang,Qian Chen,Xin Yu,Menglu Zhang,Mingbao Feng
The increased release of various emerging organic contaminants into natural waters has posed great threats to ecological safety and public health. The ensuing global water contamination has necessitated the development of highly efficient treatment strategies for water purification . Herein, we presented for the first time that the combined utilization of permanganate (Mn(VII)) and periodate (PI) could synergistically and rapidly accomplish complete destruction of different organic micropollutants (e.g., bisphenol F, methotrexate, and tetracycline) within 2–5 min. Comparatively, the single treatment only eliminated very small amounts of micropollutants. Mechanistic investigations were performed using the trapper-based electron spin resonance , scavenging and probe experiments, UV–vis spectra analysis, determination of iodine species, and multiple validation tests. These data collectively suggested that the highly reactive Mn(V)/Mn(VI) intermediates played the leading role in accelerating contaminant abatement within the Mn(VII)/PI oxidation system. Reactive oxygen/or iodine species ( 1 O 2 , OH, O 2 - , IO 3 , and IO 4 ) and low valence Mn species (Mn(II), Mn(III), and in-situ formed MnO 2 colloids) did not participate in decontamination in this process. Subsequently, the oxidized products of three micropollutants were determined, and the transformation pathways were clarified. Ring-opening, C-C bond cleavage, demethylation, carbonylation , and hydroxylation reactions mainly occurred in the degradation process. Notably, the combined system did not yield any toxic iodinated end products. Finally, the environmental risks of the degradation products were also evaluated based on in silico QSAR-based prediction tools. Overall, this study provides a novel, highly efficient, and green treatment technology, i.e., Mn(VII)/PI system, which could be employed for rapid and sustainable water decontamination.
研究领域:
环境科学
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水处理
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化学工程
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污染控制
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产品关联
DOI
高影响因子
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