Environmental Technology & Innovation
·
2025
·
IF 7.1
Changsheng Jin,Yin Gao,Jingjing Lu,Yuxi Liu,Baowei Hu
Soils contain abundant organic matter (OM) and Mn(oxyhydr)oxides (MnOs) composites, which primarily control the geochemical behavior of Cd. However, the impact of manganese phase transformation on the retention and availability of Cd remains unclear. Here, four organo-mineral composites were synthesized using birnessite (δ-Mn Ⅳ O 2 ), β-Mn Ⅲ,Ⅳ O 2 , γ-Mn Ⅲ OOH, and Mn Ⅱ,Ⅲ 3 O 4 with fulvic acid (FA), during adsorption to preformed MnOs with 5 wt% organic carbon loadings. The performance and underlying Cd(II) adsorption mechanism by resulting FA-MnO composites were explored. Results showed that δ-MnO 2 transformation decreases Cd(II) adsorption capacity by 23.02–45.44 % on the resulting FA-MnOs. This reduction was attributed to increased aggregation of MnO particles and competition from generated Mn(II/III) for available vacancy sites. Cd undergoes redistribution within the FA-MnOs during the transformation of δ-MnO 2 . The amount of Cd associated with MnOs decreases by 9.46–37.08 %, while OM bound-Cd increases by 2.82–10.49 %. FAδ-MnO 2 predominantly interacted with Cd(II) through tetravalent manganese, forming stable coordination or chemical bonds. In contrast, FAγ-MnOOH and FA-Mn 3 O 4 primarily interacted with Cd(II) through divalent manganese via electrostatic attraction and ion exchange, resulting in weaker binding stability. These findings provide new insights into the roles of manganese transformation in the geochemical cycling of Cd in soils.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2020
·Vol. 21
·期 5
·1709
·
IF 4.556
Juan Guo,Huan Guo,Jin Liu,Fangrui Zhong,Yuzhou Wu
Manganese oxidizing bacteria can produce biogenic manganese oxides (BMO) on their cell surface and have been applied in the fields of agriculture, bioremediation, and drinking water treatment to remove toxic contaminants based on their remarkable chemical reactivity. Herein, we report for the first time the synthetic application of the manganese oxidizing bacteria,Pseudomonas putidaMnB1 as a whole-cell biocatalyst for the effective oxidation of β-keto ester with excellent yield. Differing from known chemical protocols toward this transformation that generally necessitate the use of organic solvents, stoichiometric oxygenating agents and complex chemical catalysts, our strategy can accomplish it simply under aqueous and mild conditions with higher efficiency than that provided by chemical manganese oxides. Moreover, the live MnB1 bacteria are capable of continuous catalysis for this C-O bond forming reaction for several cycles and remain proliferating, highlighting the favorable merits of this novel protocol for sustainable chemistry and green synthesis.Keywords:Pseudomonas putidaMnB1;biogenic manganese oxides;abiotic manganese oxides;α-Hydroxy-β-keto esters;whole-cell biocatalysis
研究领域:
生物催化
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绿色化学
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有机合成
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环境生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Shunli Wan,Lian Qiu,Yan Li,Junjie Sun,Bin Gao,Feng He,Wubo Wan
Antimony and copper pollution pose significant threat to water quality security, and their advanced treatment is still a great challenge. In this study, we fabricated a hybrid adsorbent (denoted as MO-L-BC) through dispersing manganese oxide (MO) inside a biochar with enlarged pore structure (namely L-BC). The used carrier L-BC possessed a high proportion of large pores (>2 nm) (87%), and thus lowered the diffusion resistance of target pollutants in pore region of MO-L-BC. Consequently, Sb(III) and Cu(II) adsorption onto MO-L-BC achieved equilibrium within 15 min, and their effective coefficients of intra-particle diffusion (D) were calculated to be 8.6 × 10 −8 and 1.5 × 10 −7 cm 2 s −1 , respectively, which were only one-order magnitude lower than that in aqueous phase. XPS analysis indicated that 53.3% of the sorbed Sb(III) was oxidized to Sb(V) by the impregnated MO. Coexisting substances such as HCO 3 − , SO 4 2− , NO 3 − , Ca 2+ , Mg 2+ and humic acid up to 20 times higher concentration than target contaminants (Sb(III) or Cu(II)) caused only < 20% drop in sorption capacity of MO-L-BC, and the mutual effect of Sb(III) and Cu(II) was also not noticeable. The fixed-bed column adsorption tests showed that MO-L-BC can achieve the tertiary treatment of either the singly polluted (Sb(III) or Cu(II)) or the co-contaminated wastewater at a high flow rate of 0.27 m h −1 , with effective treatment volumes larger than400 BV, and the saturated MO-L-BC can be effectively regenerated. MO-L-BC is a promising engineered biochar to treat Sb(III) and/or Cu(II) contaminated water especially under high-flow conditions.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Quanfeng Wang,Haoxuan Wei,Wenbo Liu,Jun Zhai
Forty strains of Mn-oxidizing microalgae (MnOMs) with different Mn 2+ oxidation mechanisms were identified from two aquatic environments. Among them, three strains of isolates ( Chlamydomonas sp. WH1–1, Chlamydomonas sp. WH1–4 , and Chlorella sp. WH2–5) oxidize Mn 2+ by increasing the ambient pH and by secreting Mn oxidation factors (e.g., superoxide-production enzymes and/or other Mn oxidases) into the extracellular environment at the same time. In carbamazepine (CBZ) removal by MnOMs and/or Bio-MnOx, the combination of MnOMs and Bio-MnOx significantly increased the CBZ (1 mg/L) removal efficiency from 36.05% (by MnOMs alone) and 20.11% (by Bio-MnOx alone) to 80.13% by two synergistic mechanisms. One of the synergistic mechanisms was confirmed as that the Mn 2+ was re-oxidized by MnOMs to Bio-MnOx, which can promote the CBZ removal, and another was the mutual exchange of degradation products of CBZ as shared reactants between MnOMs and Bio-MnOx. The degradation intermediates of CBZ were analyzed using high-performance liquid chromatography-tandem mass spectrometry , based on which the CBZ degradation pathway by MnOMs and Bio-MnOx was proposed. These findings expand existing knowledge on the Mn 2+ oxidation mechanisms of MnOMs, and indicate that MnOMs and their generated Bio-MnOx are promising for the removal of CBZ or other pharmaceutical contaminants from wastewater.
研究领域:
环境科学
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微生物学
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制药工程
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Jian Deng,Chunhao Wang,Shenggui Ma,Chengchao Liu,Yongtao Zheng,Haipeng Chen,Ruofei Chen,Siyu Wei,Shanbi Peng,Xia Jiang
In this study, Cu 1.5 Mn 1.5 O 4 spinel with Mn(Ⅳ)O 6 coordination was synthesized by evaporation and combustion method. CuMn-500-1 catalyst was obtained by acid etching, which significantly promotes the catalytic oxidation of toluene (lowering ≈ 30℃ regarding T 100 ). Characterization results demonstrate that the enhanced performance can be attributed to the increased exposure of (222) crystal facet of a more rod-like Cu 1.5 Mn 1.5 O 4 spinel, independent of surface area and oxygen vacancy (which remained almost unchanged). In addition, the rate-determining steps were proved to be the ring-opening reaction of phenol by in-situ DRIFTS experiment. Density functional theory calculation further shows that the Mn(Ⅳ)O₆ site exhibits stronger capacity for toluene adsorption. In addition, the main cause underlying the enhanced performance of CuMn-500-1 is further corroborated: specifically, the (222) crystal surface demonstrates stronger catalytic performance compared to other crystal faces. This strategy provides a new method in enhancing the VOCs removal efficiency of catalyst.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
Small
·
2024
·
IF 13
Cheng Gu,Shu Fang,Lin Liu,Benjin Chen,Lingling Xu,Min Shao,Jianan Sun,Haisheng Qian,Wanni Wang
The production of bacterial toxins and excessive accumulation of reactive oxygen species (ROS) can induce localized oxidative stress, triggering an exaggerated immune response that impedes wound healing and culminates in chronic wounds. To address this issue, a microneedle (MN) system loaded with copper-manganese oxide (CMO) is developed to modulate the hyperimmune response in wounds. CMO@MN exhibits excellent antimicrobial and anti-inflammatory properties by effectively killing bacteria, scavenging ROS, and modulating macrophage polarization through their multiple enzymatic activities and photothermal properties. RNA sequencing revealed that CMO@MN improved the therapeutic effect on the infected skin of mice by balancing the ratio of M1/M2 macrophages and promoting cell migration and angiogenesis through the regulation of relevant pathways. Overall, this CMO@MN patch skillfully balances the complex issues between the immune response and wound healing and has potential applications in the treatment of other serious bacterial infections.
研究领域:
生物医学工程
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免疫学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Shunli Wan,Chunlei Yu,Yan Li,Zhongxiang Lu,Yuchen Wang,Yan Wang,Feng He
Advanced treatment of heavy metals from various types of water is challenging but of great urgency due to their serious threat to water quality security. In this study, a new magnetic hybrid adsorbent with the core-shell structure, which is denoted as Fe 3 O 4 @SiO 2 @MO, was prepared by successively covering SiO 2 and manganese oxide (MO) on Fe 3 O 4 . The covered SiO 2 was designed to protect the magnetic core Fe 3 O 4 from acid corrosion in practical application. The Fe 3 O 4 @SiO 2 @MO can be separated from solution within 10 s using an external magnetic field and very quickly remove Cd(II) and Cu(II) with equilibrium time below 10 min due to its special coating structure, which sharply reduces the diffusion distance of two metals before adsorption. Their effective coefficients of intraparticle diffusion (D) were determined to be 2.0 × 10 −10 and 8.5 × 10 −10 cm 2 s −1 . High levels of Ca(II) and Mg(II) inconspicuously affected the Cd(II) and Cu(II) retention onto Fe 3 O 4 @SiO 2 @MO, and only a decrease in removal below 20 and 12% for Cd(II) and Cu(II) occurred, respectively, due to the specific inner-sphere complexation between MO and the targeted metals. We preliminarily uncovered this interaction using XPS and FTIR analyses. Furthermore, in cyclic batch experiments, 1 kg Fe 3 O 4 @SiO 2 @MO can effectively treat 0.5 and 3.25 m 3 of Cd(II)- and Cu(II)-contaminated wastewater to satisfy their corresponding discharge standards, respectively, which is equivalent to 500 and 3250 folds of its own weight. All results validate that Fe 3 O 4 @SiO 2 @MO is a promising engineered magnetic adsorbent to decontaminate heavy-metal-polluted wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Minxian Xu,Li Chen,Weiliang Zhou,Xi Liu,Dongzhen Lu,Minglu Zhang,Zheru Shi
The demand for energy storage equipment in the information age era is becoming increasingly scarce, but manganese-based metal oxides with large potential windows and multivalent states were developed and used as high-performance electrode materials for energy storage. MnO 2 array grow on the carbon sphere as the precursor and then obtain multi-types and hierarchical of manganese metal oxides through gradient carbonization. The surface crystal phase changes with temperature, and the electrochemical performance shows obvious imparity. In addition, the carbon spheres gradually disappear with increasing temperature forming a hollow shell structure, which is conducive to sufficient contact between electrolyte and electrode material. It found that the annealing temperature can change the surface oxide morphology of MnO 2 /C, and it can know that the temperature promotes the conversion of MnO 2 to Mn 2 O 3 and Mn 3 O 4 . Based on the oxides of different crystal phases, the electrochemical properties are more distinctive due to their different structures. The rod-like nanoarray Mn 2 O 3 /C composites derived from annealing the precursors at 600 °C show high specific capacity and rate performance under a very large potential window of 0~1.2 V (show a remarkable specific capacitance of 277.0 F·g −1 at a current density of 1.0 A·g −1 ). Considering practical application, the as-assembles Mn 2 O 3 /C//Na 2 SO 4 //Mn 2 O 3 /C symmetrical supercapacitors device exhibits a maximum energy density of 80.35 Wh·kg −1 at a power density of 500 W·kg −1 , which can be applied promising storage materials for information age.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 83
·67951-67961
·
IF 3.84
Jin Zhu,Zimo Lou,Yu Liu,Ruiqi Fu,Shams Ali Baig,Xinhua Xu
Iron–manganese binary oxide (FeMnOx) is considered highly effective for arsenic adsorption, however, the agglomeration effect hindered its practical application. In this study, graphene has been used as a supporting matrix to disperse FeMnOx due to its huge specific surface area, and the synthesized novel composite adsorbent (FeMnOx/RGO) was employed for arsenic removal. Results demonstrated that FeMnOx/RGO (mass ratio of FeMnOx to FeMnOx/RGO nanocomposites is 45%) has larger specific surface area (411 m2 g−1) in comparison with bare FeMnOx, and showed 10.16 mg As g−1 FeMnOx and 11.49 mg As g−1 FeMnOx adsorption capacities for As(III) and As(V), respectively, with 1 mg L−1 initial concentration. Increased in the initial concentration to 7 mg L−1, the adsorption capacities of As(III) and As(V) reached to 47.05 mg As g−1 FeMnOx and 49.01 mg As g−1 FeMnOx, respectively. The removal process perfectly obeys pseudo second-order kinetic model for both As(III) and As(V). And PO43− was found to strongly inhibit arsenic adsorption. Furthermore, adsorption tests and characterization analyses confirmed that MnO2 played a key role on the oxidation of As(III), while iron(III) oxide was found crucial to As(V) removal. Electrostatic interaction and surface complexation mechanisms involved in the adsorption. These findings suggested that the adsorbent could be used in real arsenic-contaminated water treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Ruya Chen,Yuan Zhuang,Ying Yu,Baoyou Shi
Particulate manganese oxide (MnOx) deposition in drinking water distribution systems (DWDS) gives rise to the risk of water discoloration at the consumers’ tap; however, its role in the fate and transport of trace organic pollutants in DWDS is not clear. Perfluorooctanoic acid (PFOA), a persistent organic pollutant frequently detected in natural water, was selected to investigate the potential effect of MnOx on its transportation behavior under DWDS conditions through laboratory batch experiments. The results show that PFOA can be greatly combined with MnOx formed in-situ through a Mn(II) oxidation process by free chlorine. However, the accumulation of PFOA by preformed MnOx was negligible. It was found that 1 mg/L Mn captured over 50% of PFOA with an initial concentration of 50 ng/L during oxidation. The water compositions of actual water could contribute to the effect of PFOA accumulation to a certain extent. Characterization of the solid products revealed that PFOA is homogenously embedded into MnOx. The combination of PFOA with MnOx occurs through a bridging effect of Mn(II) between the surface hydroxyls of MnOx and the -COOH group of PFOA. The resulting MnOx-PFOA particles were more inclined to agglomerate, enabling possibly easy deposition onto the pipe wall than ordinary MnOx particles. This study provides insights into the co-occurrence of metal deposits with PFOA and the potential risks posed by PFOA accumulation to consumers through the water distribution process.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2018
·Vol. 9
·期 1
·10
·
IF 3.504
Yuelong Xu,Bin Ren,Ran Wang,Lihui Zhang,Tifeng Jiao,Zhenfa Liu
In the present study, nanoscale rod-shaped manganese oxide (MnO) mixtures were successfully prepared from graphitic carbon nitride (C3N4) and potassium permanganate (KMnO4) through a hydrothermal method. The as-prepared MnO nanomixtures exhibited high activity in the adsorption and degradation of methylene blue (MB). The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the effects of the dose of MnO nanomixtures, pH of the solution, initial concentration of MB, and the temperature of MB removal in dye adsorption and degradation experiments was investigated. The degradation mechanism of MB upon treatment with MnO nanomixtures and H2O2was studied and discussed. The results showed that a maximum adsorption capacity of 154 mg g−1was obtained for a 60 mg L−1MB solution at pH 9.0 and 25 °C, and the highest MB degradation ratio reached 99.8% under the following optimum conditions: 50 mL of MB solution (20 mg L−1) at room temperature and pH ≈ 8.0 with 7 mg of C, N-doped MnO and 0.5 mL of H2O2.Keywords:hydrothermal method;manganese oxide;adsorption;degradation;nanomixtures
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Min Xu,Lei Wang,Yonggang Sun,Yulong Ma,Xin Zhang,Juan Zhang,Yingbo Zhu,Li Zhu,Song Qiao,Jinpeng Wei,Wenxin Ji,Feng Lin
Spinel is a powerful non-precious metal oxide catalyst that can be used to catalyze the combustion of volatile organic pollutants, potentially replacing precious metal catalysts. To enhance the catalytic activity and stability of CuMn 2 O 4 , we constructed gradient distribution of oxygen vacancies (V o ) on the CuMn 2 O 4-δ surface utilizing alkali treatment method. Alkali treatment dissolves some of the Cu atoms of the CuMn 2 O 4 catalyst, leading to the transformation of part of the Mn-O-Cu structure into the Mn-O structure, which was results in the lengthening of the Mn-O bond and the production of cation defects. The Mn-O bond breaks, releasing a large amount of reactive oxygen and forming oxygen vacancies. Highly reactive lattice oxygen and cation defects is more likely to participate in oxidation reactions. In the catalytic combustion of acetone, the alkali-treated catalyst showed high activity and stability, and the oxidation rate of acetone at 170 °C was increased by 2.86 times. Particularly, the alkali treatment catalysts can convert acetone that has been adsorbed into acetic acid and formic acid using catalyst lattice oxygen in anoxic environment. In the presence of an oxygen stream, the acetic and formic acids underwent direct oxidation, resulting in the formation of water and carbon dioxide. This work promotes the development of oxygen vacancy engineering on the surface of transition metal oxides and provides a new approach to improve the activity and stability of CuMn 2 O 4 in real environments.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）