Water
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2019
·Vol. 11
·期 11
·2302
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IF 2.524
Dingyun Yan,Zhe Sun,Jiajie Wang,Lili Wang,Ruijun Pan,Qiang Wu,Xiaowei Liu
Mn(III) oxidation technology has attracted increasing interest in recent years because of its fast decontamination kinetics and second-pollution-free characteristic. Whether it can be used as a pre-oxidation step to enhance conventional coagulation process remains to be evaluated. Herein, an Fe-coagulation/sedimentation process combined with Mn(III) pre-oxidation (Mn(III)+C/S), hypochlorite pre-oxidation (Cl2+C/S), and permanganate pre-oxidation (PM+C/S) was applied to treat simulated micro-polluted raw water. The removal performance of routine water quality indices (turbidity, dissolved organic carbon, total nitrogen, nitrate-nitrogen, ammonia-nitrogen, Pb(II), and Cr(VI)) and the emerging pollutants (acesulfame, carbamazepine, bisphenol S, and nano-ZnO) created by these three processes were researched. The mechanism of how Mn(III) pre-oxidation influences C/S was explored by identifying the transformation products of Mn(III), measuring the timely variation of flocs’ zeta potential and size, and scanning flocs’ micromorphology. Compared to Cl2+C/S and PM+C/S, Mn(III)+C/S exhibited its superiority in removing dissolved organic carbon (72.9%), total nitrogen (31.74%), and emerging pollutants (21.78%–93.49%). The enhanced removal of these contaminants by Mn(III)+C/S found its explanation in the strong oxidation power of Mn(III) and the multiple roles of in-situ formed MnO2(e.g., flocculation core, adsorption co-precipitant, and densification agent). The acute toxicity tests confirmed that water treated by Mn(III)+C/S did not show a significant change in the associated toxicity. The findings of the present study indicate that Mn(III) oxidation technology shows great potential as an alternative to pre-oxidation technology of waterworks.Keywords:pre-oxidation;enhanced coagulation;Mn(III);emerging pollutants;micro-polluted raw water
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
CATALYSIS COMMUNICATIONS
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2022
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IF 3.51
Haoxuan Wei,Jujiao Zhao,Md. Hasibur Rahaman,Quanfeng Wang,Jun Zhai
In this study, the catalytic activity of soluble Mn(III) ions, soluble Mn(III)-pyrophosphate (PP), and solid Mn(III) (α-MnO 2 ) towards peroxymonosulfate (PMS) activation was investigated through carbamazepine (CBZ) degradation. The degradation efficiency of CBZ was negligible when soluble Mn(III) ions or Mn(III)-PP were used as catalysts, while 99.7% of CBZ was degraded in the α-MnO 2 /PMS system with no soluble Mn(III) ions detected. The degradation efficiency of CBZ reduced by 18% with the solid Mn(III) content decreasing. Hence, the solid Mn(III) made the major contribution to PMS activation. This study supported a better understanding of the role of Mn(III) in PMS activation.
研究领域:
环境化学
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催化
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水处理
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DOI
高影响因子
International Journal of Environmental Research and Public Health
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2022
·Vol. 19
·期 15
·9437
·
IF 4.614
Qianli Guo,Xianhu Qi,Jian Zhang,Bo Sun
Aqueous complexes of Mn(III) ion with ligands exist in various aquatic systems and many stages of water treatment works, while HSO3−is a common reductant in water treatment. This study discloses that their encounter results in a process that oxidizes organic contaminants rapidly. Pyrophosphate (PP, a nonredox active ligand) was used to prepare the Mn(III) solution. An approximate 71% removal of carbamazepine (CBZ) was achieved by the Mn(III)/HSO3−process at pH 7.0 within 20 s, while negligible CBZ was degraded by Mn(III) or HSO3−alone. The reactive species responsible for pollutant abatement in the Mn(III)/HSO3−process were SO4•−and HO•. The treatment efficiency of the Mn(III)/HSO3−process is highly related to the dosage of HSO3−because HSO3−acted as both the radical scavenger and precursor. The reaction of Mn(III) with HSO3−follows second-order reaction kinetics and the second-order rate constants ranged from 7.5 × 103to 17 M−1s−1under the reaction conditions of this study, suggesting that the Mn(III)/HSO3−process is an effective process for producing SO4•−. The pH and PP:Mn(III) ratio affect the reactivity of Mn(III) towards HSO3−. The water background constituents, such as Cl−and dissolved organic matter, induce considerable loss of the treatment efficiency in different ways.Keywords:Mn(III);bisulfite;advanced oxidation processes;sulfate radical;micropollutant abatement
研究领域:
环境化学
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水处理
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污染物降解
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DOI
PubMed
高影响因子
Nano Research
·
2023
·Vol. 16
·期 8
·10748-10755
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IF 9.9
Li Junhua,Jiang Yi,Zhang Xu,Huo Yidan,Du Fanglin,Tuo Yongxiao,Guo Zhiyan,Chen Dawei,Chen Shenghua
The electrooxidation of the alcohol and aldehyde molecules instead of water coupled with H 2 production has been proven to be effective for producing high-value fine chemicals under alkaline conditions. It is also noteworthy that under acidic conditions, the stability of non-noble metal water oxidation catalysts remains a great challenge due to the lattice oxygen mechanism. Hence, we coupled the biomass-derived glucose oxidation for high-value D-glucaric acid (GRA) with ultra-durable hydrogen in acid solution over a Yb-MnO 2 catalyst. The Mn 3+ regulated by Yb atoms doped in MnO 2 can effectively optimize the adsorption and desorption processes of the alcohol and aldehyde group and improve the intrinsic activity but cannot for H 2 O. The catalyst exhibited extremely high activity and stability after 50 h for glucose oxidation, inhibiting the lattice oxygen process and MnO 4− formation, while the activity was quickly lost within 0.5 h for water oxidation. Density functional theory (DFT) calculations further demonstrated that glucose oxidation reaction proceeds preferentially due to the oxidation of aldehyde group with lower adsorption-free energy (−0.4 eV) than water (Δ G > 0 eV), avoiding the lattice oxygen mechanism. This work suggests that biomass-derived glucose oxidation not only provides a cost-effective approach for high-value chemicals, but also shows an extremely potential as an alternative to acidic oxygen evolution reaction (OER) for ultradurable H 2 production.
研究领域:
生物化学
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催化化学
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DOI
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Shiqi Tian,Yuwei Ma,Yuanyuan Xu,Yingzi Lin,Jun Ma,Gang Wen
Dissolved Mn(III), as a potent one-electron transfer oxidant, is ubiquitous in natural waters and sediments and actively involved in the transformation of organics in biogeochemical processes and water treatment. However, the important role of Mn(III) has long been overlooked because of its short life. This study was the first to investigate the performance of Mn(III) in organoarsenic transformation and to highlight the environmental implications. Both homogeneous and heterogeneous Mn(III)-based systems were effective to remove p -arsanilic acid ( p -ASA, 15 μ M) with degradation efficiency approaching 40.4 %–98.3 %. Two degradation pathways of p -ASA were proposed, in which As-C bond and amino group were vulnerable sites to Mn(III) attack, leading to the formation of more toxic arsenate (As(V)) and nitarsone. Through transforming organoarsenic to inorganic arsenic species, the removal efficiency of total arsenic and dissolved organics were enhanced to 65.1 %–95.5 % and 16.6 %–36.6 %, respectively, by post-treatment of coagulation or adsorption, accompanied with significant reduction of cytotoxicity and environmental risks. Particularly, polymeric ferric sulfate and granular activated alumina showed superior performance in the total As removal. Moreover, oxidation efficiency of Mn(III) was hardly affected by common cations and anions (e.g., Ca 2+ , Mg 2+ , NH 4 + , NO 3 ˉ, SO 4 ˉ), halide ions (e.g., Clˉ, Brˉ) and natural organic matter, showing high robustness for organoarsenic removal under complicated water matrices. Overall, this study shed light on the significance of Mn(III) to the fate of organoarsenics in manganese-rich environments, and demonstrated the promising potential of Mn(III)-based strategies to achieve targeted decontamination in water/wastewater purification.
研究领域:
环境科学
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水处理工程
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毒理学
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DOI
PubMed
高影响因子
ACS Nano
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2019
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IF 13.903
Shuang-Shuang Wan,Qian Cheng,Xuan Zeng,Xian-Zheng Zhang
Here, a Mn(III)-sealed metal–organic framework (MOF) nanosystem based on coordination between Mn(III) and porphyrin (TCPP) via a one-pot method was designed and constructed. Mn(III), as a sealer, not only quenched TCPP-based fluorescence but also inhibited reactive oxygen species (ROS) generation, which made MOFs an “inert” theranostic nanoparticle. Interestingly, upon endocytosis by tumor cells, MOFs were disintegrated into Mn(II) and free TCPP by intracellular glutathione (GSH) in tumor cells, owing to redox reaction between Mn(III) and GSH. This disintegration would lead to consumption of antioxidant GSH and activated Mn(II)-based magnetic resonance imaging (MRI) as well as TCPP-based fluorescent imaging. More importantly, such a GSH-regulated TCPP release could implement controllable ROS generation under irradiation, which avoided side effects (inflammation and damage of normal tissues). As a consequence, after unlocking by GSH, Mn(III)-sealed MOFs could significantly improve the therapeutic efficiency of photodynamic therapy by combining controlled ROS generation and GSH depletion after precise dual tumor homing.
研究领域:
纳米技术
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癌症研究
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生物医学工程
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Yuxi Zhang,Yamin Deng,Jiangkai Xue,Yihan Cheng,Yulun Nie,Kunfu Pi,Yao Du,Xianjun Xie,Jianbo Shi,Yanxin Wang
The environmental fate of arsenic (As) relies substantially on its speciation, which occurs frequently coupled to the redox transformation of manganese. While trivalent manganese (Mn(III)), which is known for its high reactivity, is believed to play a role in As mobilization by iron (oxyhydr)oxides in dynamic aquifers, the exact roles and underlying mechanisms are still poorly understood. Using increasingly complex batch experiments that mimick As-affected aquifer conditions in combination with time-resolved characterization, we demonstrate that Mn(III)-NOM complexes play a crucial role in the manganese-mediated immobilization of As(III) by ferrihydrite and goethite . Under anaerobic condition , Mn(III)-fulvic acid (FA) rapidly oxidized 31.8% of aqueous As(III) and bound both As(III) and As(V). Furthermore, Mn(III)-FA exerted significantly different effects on the adsorption of As by ferrihydrite and goethite. Mn(III)-FA increased the adsorption of As by 6–16% due to the higher affinity of oxidation-produced As(V) for ferrihydrite under circumneutral conditions. In contrast, As adsorption by crystalline goethite was eventually inhibited due to the competitive effect of Mn(III)-FA. To summarize, our results reveal that Mn(III)-NOM complexes play dual roles in As retention by iron oxides , depending on the their crystallization. This highlights the importance of Mn(III) for the fate of As particularly in redox fluctuating groundwater environments.
研究领域:
环境科学
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地球化学
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水文地质学
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DOI
PubMed
高影响因子
Molecular Catalysis
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2020
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IF 3.687
Anwei Wang,WeiYou Zhou,Zhonghua Sun,Zhong Zhang,Zhihui Zhang,MingYang He,Qun Chen
Developing efficient heterogeneous catalytic systems based on easily available materials and molecular oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni 2 Mn-LDH) has been found as an efficient catalyst in the oxidation of alkylarenes using molecular oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system have been observed. Mn 3+ species was proposed to be the efficient active site, and Ni 2+ played an important role in stabilizing the Mn 3+ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni 2 Mn-LDH with the activation energy ( E a ) and pre-exponential factor ( A 0 ) being 85.7 kJ mol −1 and 1.8 × 10 9 min −1 , respectively. The Gibbs free energy (Δ G ≠ ) was determined to be -10.4 kJ mol -1 K -1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by molecular oxygen and H 2 O or hydroxyl species, respectively, to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.
研究领域:
催化
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化学工程
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材料科学
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物理化学
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DOI
高影响因子
POLYHEDRON
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2017
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IF 1.926
Xiu-Mei Zhang,Jie Tang,Li-Na Wang,Di Yao,Qing Yu,Fu-Ping Huang,He-Dong Bian
Mimetics of superoxide dismutases (SOD), with certain ability to eliminate superoxide radicals under aerobic conditions, would be promising as drug candidates for antioxidant therapy. Many efforts have been devoted to synthesize small molecular compounds to mimic the functionality of natural SOD. In this paper, the Mn(III)/Co(III)/Fe(III) complexes have been synthesized with the Schiff base ligand (NaH 2 L), which was condensed from 2-hydroxynaphthalen-1-naphthaldehyde and 3,4-diaminobenzenesulfonic acid. The structures of complexes 1 and 3 have been determined by X-ray crystallographic method, and all the complexes have been investigated using FT-IR, MS. The binding constants between metal complexes and bovine serum albumin (BSA) have been determined by fluorescence spectroscopy. Meanwhile, we have synthesized 3 hybrid proteins through the interaction of the complexes and BSA. The SOD-like activity was tested by xanthine/xanthine oxidase method. The result shows that BSA molecule can increase the SOD activity of the transition metal complexes.
研究领域:
无机化学
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生物化学
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药学
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DOI
高影响因子
Journal of Earth Science
·
2019
·Vol. 30
·期 4
·861-869
·
IF 1.784
Zhang Caixiang,Liao Xiaoping,Lü You,Nan Chao
The ligand-stabilized soluble Mn(III) recognized as active intermediate can potentially mediate the attenuation of contaminants. In this study, the abiotic degradation behaviors of methyl parathion in the ligand stabilized Mn(III)-sulfite system were investigated. The results showed that the yield of soluble Mn(III) produced from the redox reaction of MnO 2 and oxalic acid was dependent linearly on the dosage of MnO 2 and caused the decomposition of methyl parathion up to 50.1% in Mn(III)-sulfite system after 30 minutes. The fitted pseudo-first-order reaction constants of methyl parathion degradation increased with the increasing of the amount of produced Mn(III) but was not effected linearly by the addition of sulfite. Other ligands, including pyrophosphate and oxalic acid, acted as effective complexing agents to stabilize soluble Mn(III), and exhibited competitive effect on methyl parathion degradation with sulfite. The formation of Mn(III)-sulfite complexes is the critical step in the system to produce abundant reactive oxygen species identified as SO 3 • - to facilitate methyl parathion degradation. The hydrolysis and oxidation of methyl parathion were acknowledged as two primary transformation mechanisms in Mn(III)-sulfite system. These findings indicate that naturally ligands-stabilized soluble Mn(III) can be generated and could oxidatively decompose organophosphate pesticides such as methyl parathion.
研究领域:
环境科学
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化学
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DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Lijun Zhu,Hao Cheng,Jianfeng Ma,Yong Kong,Yong Qin,Sridhar Komarneni
Decolorization of methyl orange (MO) by MnO 2 was investigated with and without small molecules of organic acids such as formic acid. It was found that the decolorization could be significantly improved by MnO 2 with the assistance of organic acids. The effect of various conditions was investigated on MO decolorization by using different crystal types of MnO 2 and changing the types of organic acids. One of the optimum treatment conditions was δ-MnO 2 /formic acid system, which led to the removal efficiency of 90.6% at 30 min. The pseudo-second-order kinetic rate constant of δ-MnO 2 /formic acid was 0.1626. A reasonable decolorization mechanism involving Mn(III) species was proposed and the mechanism was validated by simple detection of ionic species such as, Mn(II) and Mn(III) during the reaction. The δ-MnO 2 /formic acid process designed here may lead to a new advanced oxidation technology based on the in-situ generation of active Mn(III) species and their ability for oxidation.
研究领域:
环境科学
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化学
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DOI
高影响因子
WATER RESEARCH
·
2017
·
IF 6.942
Erdan Hu,Ya Zhang,Shuyan Wu,Jun Wu,Liyuan Liang,Feng He
Mn(III) is a strong oxidant for one electron transfer , which may be important in the transformation of organic contaminants during water/wastewater treatment and biogeochemical redox processes. This study explored the reaction mechanisms of dissolved Mn(III) with organics. The role of dissolved Mn(III) either as a catalyst or an oxidant in reactions with organics was recognized. Aquo and/or hydroxo (or free) Mn(III), generated from the bisulfite activated permanganate process, facilitated efficient N-dealkylation of atrazine via a β-elimination mechanism, resulting no net redox reaction. In contrast, free Mn(III) degraded 4-chlorophenol via intramolecular redox processes, the same as hydroxyl radical ( OH), resulting in dechlorination , OH substitution, ring-opening and mineralization. Mn(III)-pyrophosphate compounds did not react with atrazine because complexation by pyrophosphate rendered Mn(III) unable to bond with atrazine, thus the electron and proton transfers between the reactants couldn't occur. However, it degraded 4-chlorophenol at a slower rate compared to free Mn(III), due to its reduced oxidation potential. These results showed two distinct mechanisms on the degradation of organic contaminants and the insights may be applied in natural manganese-rich environments and water treatment processes with manganese compounds .
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
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