WATER RESEARCH
·
2024
·
IF 11.4
Xuecong Qian,Shilong Wang,Haijun Cheng,Luwei Li,Yun Liu,Jinhao Duan,Da Wang,Jun Ma
Fe(II) and Mn(II) are abundant in groundwater and require operationally simple and efficient method to remove in drinking water treatment. The rapid oxidation of Mn(II) is essential in water treatment. This study investigates the efficiency of Mn(II) oxidation by free chlorine in the presence of Fe(II). The results demonstrate that the presence of Fe(II) significantly accelerates the oxidation rate of Mn(II) by free chlorine under neutral and alkaline conditions. The rapid oxidation of Fe(II) by free chlorine and the presence of Mn(II) promote the formation of in situ Mn(II)-doped ferrihydrite. Kinetic modeling and characterization of Fe(III) oxides confirm that the heterogeneous catalytic effect of the Mn(II)-doped ferrihydrite, rather than manganese oxides or their coupled catalytic effect, is responsible for the enhanced oxidation rates. The doped Mn(II) substitutes the tetrahedral Fe(III) ions in the ferrihydrite, introducing additional negative charges at the doped sites. The increased charge enhances Mn(II) adsorption and lowers its redox potential, thereby accelerating Mn(II) oxidation rate through direct electron transfer with adjacent free chlorine. Additionally, the lepidocrocite formed by the reaction between Fe(II) and dissolved oxygen significantly impedes the catalytic performance. These findings provide new insights into the catalytic co-oxidation mechanism of Fe(II) and Mn(II), and help the optimization of water treatment engineering practices.
研究领域:
环境科学
·
水处理工程
·
化学动力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Zhuozhi Ouyang,Fadan Lei,Endian Hu,Shuxing Li,Qian Yao,Xuetao Guo
Tetracycline (TC) and Mn(II) is a common antibiotic and metal ion respectively. Nevertheless, literatures involving in the effects of Mn(II) on TC transformation are still insufficient. In this study, the kinetic experiment, spectral analysis, complexation experiment and electrochemical analysis, theoretical calculation and products detection were carried out to probe into oxidation and photolysis of TC with Mn(II). Mn(II) greatly accelerated TC oxidation, preferably tending to complex with TC at O10 – O12 or O2 – O3 site. There were a TC-Mn(II)/TC-Mn(III) redox couple and electron transfer process. Conversely, Mn(II) inhibited photolysis of TC. The photolysis of excited TC could compete with energy dissipation reactions. The electron transfer and complexation reaction easily made excited TC energy transfer, thus slowing down photolysis process. During the TC transformation, the intensity of functional groups was significantly decreased. Simultaneously, the degradation pathways mainly included eight reactions. It is a very interesting and probably overlooked phenomenon, which identifies new transformation of TC with Mn(II). This study helps to further understand fate and environmental behavior of antibiotics and metal ion .
研究领域:
环境化学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Xuecong Qian,Shilong Wang,Haijun Cheng,Ziye Jia,Da Wang,Yandong Xie,Jinhao Duan,Yu Tian,Jun Ma
The oxidation kinetics of Mn(II) by free chlorine is relatively low under near-neutral pH conditions which limits the Mn removal efficiency in drinking water treatment. Therefore, this study investigated the oxidation efficiency of Mn(II) by the UV-enhanced chlorination (UV/chlorine) system and identified the responsible reactive radical species. The results show that the oxidation kinetic of Mn(II) was greatly enhanced by the UV/chlorine system under near-neutral pH or even acidic conditions. The pseudo-first-order reaction rate of Mn(II) at pH 8.0 (within the first 20 min) increased from 2.60 × 10 −5 s −1 to 3.41 × 10 −4 s −1 . Based on the scavenging experiments and the steady-state kinetic modeling, ClO · and ClO 2 , whose steady-state concentration (∼10 −10 M and ∼10 −9 M, respectively at pH 8.0) was at least 4 orders of magnitude higher than that of HO · and Cl · , were recognized as the dominant reactive species contributing to the oxidation of Mn(II). Kinetic model calculations indicate that the contribution of ClO · to the oxidation of Mn(II) was consistently maintained above 70 %, and ClO 2 also played an important role in the oxidation of Mn(II) especially under acidic and alkaline conditions. In addition, the background components of HCO 3 − and Cl − had negligible influence on the oxidation efficiency because they barely changed the concentration of the ClO · and ClO 2 . This study first demonstrates the important role of ClO 2 in the oxidation of Mn(II) in the UV/chlorine system, and the possible role of ClO 2 in the degradation of some organic pollutants needs to be carefully evaluated in the future.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
·
2016
·Vol. 71
·期 8
·869-874
·
IF 0.686
Gao-Feng Wang,Xiao Zhang,Shu-Wen Sun,Hong Sun,Xia Yang,Hui Li,Chen-Zhong Yao,Shu-Gang Sun,Yu-Peng Tang,Li-Xin Meng
Two Mn(II) complexes, {[Mn(BIPMO) 2 Cl 2 ] · 2(H 2 O)} n ( 1 ) and {[Mn(BIPMO) 2 (SCN) 2 ] · 2(CH 3 OH)} n ( 2 ) (BIPMO = bis(4-(1 H -imidazol-1-yl)phenyl)methanone) with V-shaped BIPMO ligands, were synthesized and characterized by IR spectroscopy and elemental analyses along with their single-crystal X-ray diffraction analyses. The Mn(II) ions in 1 and 2 are both six-coordinated to four nitrogen atoms of four BIPMO ligands and two anions (Cl − for 1 , and SCN − for 2 ) to form a distorted octahedral geometry.
研究领域:
配位化学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Fang Li,Nuotong Shen,Qingcheng Li,Chen Yang,Limin Zhang,Mingjin Wang
The development of microfluidic flow injection analysis (FIA) system for simultaneous and real-time detection of multiple metal ions is of great importance for environmental monitoring, food safety and industrial field. In this work, a multiplexed microfluidic chip based FIA system was fabricated for simultaneous determination of three metal ions, by using Fe(III), Mn(II) and Cu(II) as models. The multiplexed microfluidic chip based FIA system is composed of three parts, including a multi-channel FIA system for solution manipulation, a group of microfluidic chips for reagents mixing and reaction, and one fiber optic spectrometer for fast and real-time absorbance signal detection. The sample solution and chromogenic reagents were injected into the microfluidic chips to carry out specific colorimetric reactions. Fe(III), Mn(II) and Cu(II) reacts with 5-sulfosalicylic acid, formaldoxime, and bis(cyclohexanone) oxalyldihydrazone, respectively, to generate orange, ember and blue colored solution with peak absorbance at 420 nm, 450 nm, and 600 nm, respectively. The absorbance signal of the generated three channels of solution can be sequentially detected by using only one mini spectrometer. The linear detection range for Fe(III), Mn(II) and Cu(II) is 0.1–20 mg/L, 0.1–12 mg/L and 0.2–12 mg/L, respectively. The limit of detection for Fe(III), Mn(II) and Cu(II) is 0.07, 0.02 and 0.1 mg/L respectively. And the limit of quantification for Fe(III), Mn(II) and Cu(II) is 0.2, 0.07 and 0.3 mg/L, respectively. The recoveries of spiked Fe (III), Mn (II), and Cu (II) in real water samples are between 95.3 % to 106 %. Finally, the developed microfluidic chip based FIA system was successfully applied to simultaneous determination of three metal ions in environmental water samples and zinc smelting solution from zinc hydrometallurgy industry with satisfied results.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Haishuo Wang,Jie Zhang,Zhichun Li,Bin Shi,Shiyin Li,Heyong Huang
Microcystin-LR (MCLR) is a highly toxic pollutant widely distributed in eutrophic waters. The interplay between dissolved organic matter (DOM) and metal ions has been extensively reported; however, the impact of DOM-metal complexes on MCLR remains to be thoroughly studied. In this research, equilibrium dialysis was employed to study the kinetics and isotherms of MCLR adsorption by DOM, meanwhile the Density functional theory (DFT) calculations provided insights into the theoretical mechanisms of Fe(II)/Mn(II) involvement in the adsorption process. The adsorption kinetics revealed that the process is physicochemical, with chemisorption being the critical factor controlling the adsorption rate. The adsorption isotherms confirmed that Fe(II) alters the spatial arrangement of adsorption sites on the superficies of DOM, with the complexes of Fe(II) and DOM from the macrophyte-dominated regions of Lake Taihu (MDR-Fe(II)) showing the uppermost adsorption capacity of 6193.965 µg/g among all combinations. The influence of different cations (K + , Ca 2+ , Na + , Mg 2+ ) on the adsorption of MCLR to DOM is divergent, with metals either reducing MCLR adsorption through competition for adsorption sites or increasing it by forming ternary complexes. The pH decrease reduced the affinity of DOM to metal ions while simultaneously enhancing MCLR adsorption through changes in its ionization state. DFT calculations demonstrated that Fe(II)/Mn(II) reduces the resistance to interaction between functional groups on DOM and MCLR, with carboxyl-Fe(II)-carboxyl interactions showing the highest binding energy (ΔG = −7.253 eV). Overall, Fe(II)/Mn(II) enhances the adsorption of MCLR via altering the structure and surface electrostatic potential distribution of DOM. This research indicates that the ultimate fate of MCLR in aquatic ecosystems is affected by DOM and metal ions.
研究领域:
环境科学
·
毒理学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2022
·
IF 2.719
Huan Zhang,Chang Liu,Yu Wang,Feifei Jia,Shaoxian Song
In this work, Mn (II) was doped into MoS 2 structure and then anchored on activated alumina beads to construct 3D-sized composites (Mn-MoS 2 @AABs). This component material was used as PMS activator for tetracycline (TC) degradation under light irradiation. According to experiment results, Mn-MoS 2 @AABs exhibited well degradation performance to TC, which ascribed to excellent photo-response property of Mn-MoS 2 and activation of Mn. Importantly, the 3D-sized structure made it facilely be recycled from solution, which catered to the demand for the practical application. Therefore, the novel strategy of designing Mn-MoS 2 @AABs had great significance for environmental restoration.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2025
·
IF 5.5
Hongjie Chen,Yixuan Su,Yucong Chen,Minghan Bao,Mingjun Wu,Junyang Chen,Weitao Chen,Qiang Ru
The inherent low electronic conductivity of NASICON-type Na4MnV(PO4)3 (NMVP) impedes its use in advanced energy storage. Herein, we address this challenge by introducing a citric acid-derived carbon coating to elevate the material’s conductivity and electrochemical performance. By precisely tailoring the configuration of the carbon layer, we fabricated Na4MnV(PO4)3 encapsulated by a carbon coating (NMVP@C) and constructed a 3D hierarchical architecture with incorporated V(III) and Mn(II) states, which prompts the reversible redox reaction, augments Na+ storage capability, and mitigates volume expansion during cycling. The optimal cathode manifests superior rate capability and a long life span with 107.5 mA h g–1 at 1 C and 82.5% capacity retention over 5000 cycles at 20 C. The hard carbon//NMVP@C full cell confirms practical applicability with good electrochemical performance. This work underscores the pivotal interplay among the carbon layer, Na+ mobility, and structural integrity in NASICON cathodes, offering a pathway to develop high-performance and cost-effective cathode materials for sodium-ion batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2016
·
IF 4.035
Songqing Chen,Xingxiu Qin,Weixi Gu,Xiashi Zhu
Ionic liquids-β-cyclodextrin polymer (ILs-β-CDCP) was attached on Fe 3 O 4 nanoparticles to prepare magnetic solid phase extraction agent (Fe 3 O 4 @ILs-β-CDCP). The properties and morphology of Fe 3 O 4 @ILs-β-CDCP were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction(XRD), size distribution and magnetic analysis. A new method of magnetic solid phase extraction (MSPE) coupled to ICP-OES for the speciation of Mn(II)/Mn(VII) in water samples was established. The results showed that Mn(VII) and total manganese [Mn(II)+Mn(VII)] were quantitatively extracted after adjusting aqueous sample solution to pH 6.0 and 10.0, respectively. Mn(II) was calculated by subtraction of Mn(VII) from total manganese. Fe 3 O 4 @ILs-β-CDCP showed a higher adsorption capacity toward Mn(II) and Mn(VII). Several factors, such as the pH value, extraction temperature and sample volume, were optimized to achieve the best extraction efficiency. Moreover, the adsorption ability of Fe 3 O 4 @ILs-β-CDCP would not be significantly lower after reusing of 10 times. The accuracy of the developed method was confirmed by analyzing certified reference materials (GSB 07-1189-2000), and by spiking spring water, city water and lake water samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yang Zong,Yufei Shao,Wenjie Ji,Yunqiao Zeng,Jun Xu,Wen Liu,Longqian Xu,Deli Wu
Traditional advanced oxidation processes (AOPs) generally suffer from the inevitable deactivation of catalysts and the ineffective consumption of transient reactive species (TRSs) that compromise the efficiency in destructing aqueous contaminants. Herein, it was interestingly found that trace Mn(II) could robustly catalyze the oxidation of organic contaminants by periodate (PI), with the performance was much better than the representative TRSs-dominated AOPs (i.e., the Fe(II)-activated hydrogen peroxide, peroxymonosulfate (PMS), peroxydisulfate and PI processes). Multiple lines of evidence excluded the oxidative contributions of TRSs, instead the stoichiometric formation of colloidal MnO 2 via the condensation of di-μ-oxo-bridged Mn(IV) cluster was confirmed by UV-vis, X-ray absorption near edge structure spectroscopy and density functional theory calculation. Dependent on the structure of substrate, MnO 2 colloids solely or simultaneously served as oxidant and catalyst for the enhanced treatment performance. Benefiting from the non-TRSs-involved oxidation strategy and the catalytic effects of Mn species, the trace-Mn(II)/PI process even outperformed the Co(II)-activated PMS counterpart (i.e., one of the most efficient AOPs known at present) on oxidant utilization efficiency. This study not only elucidated the roles of Mn(II) and colloidal MnO 2 in PI-mediated contaminant degradation, but also signified the superiority of trace catalyst-assisted process without TRSs involvement in avoiding undesired side reactions and maximizing oxidation efficiency.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Rui Wang,Huizhi Hu,Danting Shi,Jinsong Liang,Senlin Shao
Biogenic manganese oxides (BioMnO x ) can effectively remove Mn(II) from drinking water. In the gravity-driven membrane (GDM) system for Mn(II)-containing water treatment, both BioMnO x and Mn(II)-oxidizing bacteria (MnOB) present in the cake layer, and their role in Mn(II) oxidation is still controversial. To address this issue, in this study, we naturally formed a cake layer containing BioMnO x and MnOB using the GDM process and identified the different roles of BioMnO x and MnOB in the removal of Mn(II). The experimental results showed that the BioMnO x accounted for a major proportion of the cake layer of GDM, and it played a principal role in the removal of Mn(II) through the combination of adsorption and catalytic oxidation. However, this removal efficiency would be continuously reduced in the absence of MnOB, while stabilized in the presence of MnOB. XPS analysis revealed that the proportion of Mn(III) and Mn(IV) in BioMnO x with MnOB reached 64.1% and 35.8%, respectively, while BioMnO x without MnOB did not contain Mn(IV). These findings suggest that BioMnO x may be the primary catalyst for Mn(II) oxidation, but its long-term activity is dependent on MnOB, which can maintain the catalytic activity by 1) producing new BioMnO x and 2) sustaining the high valence state of MnO x .
研究领域:
环境科学
·
水处理
·
微生物学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Wen Qin,Jianshan Peng,Jingru Yang,Yang Song,Jun Ma
In this study, the relative residual UV absorbance (UV 254 ) and/or electron donating capacity (EDC) was investigated as a surrogate parameter to evaluate the abatement of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes. In the Fe(II)/PMS process, due to the generation of SO 4 •- and •OH at acidic pH, UV 254 and EDC abatement was greater at pH 5. In the Mn(II)/NTA/PMS process, UV 254 abatement was greater at pH 7 and 9, while EDC abatement was greater at pH 5 and 7. This was attributed to the fact that MnO 2 was formed at alkaline pH to remove UV 254 by coagulation, and manganese intermediates (Mn(V)) were formed at acidic pH to remove EDC via electron transfer . Due to the strong oxidation capacity of SO 4 •- , •OH and Mn(V), the abatement of micropollutants increased with increasing dosages of oxidant in different waters in both processes. In the Fe(II)/PMS and Mn(II)/NTA/PMS processes, except for nitrobenzene (∼23% and 40%, respectively), the removal of other micropollutants was greater than 70% when the oxidant dosages were greater in different waters. The linear relationship between the relative residual UV 254 , EDC and the removal of micropollutants was established in different waters, showing a one-phase or two-phase linear relationship. The differences of the slopes for one-phase linear correlation in the Fe(II)/PMS process (micropollutant-UV 254 : 0.36–2.89, micropollutant-EDC: 0.26–1.75) were less than that in the Mn(II)/NTA/PMS process (micropollutant-UV 254 : 0.40–13.16, micropollutant-EDC: 0.51–8.39). Overall, these results suggest that the relative residual UV 254 and EDC could truly reflect the removal of micropollutants during the Fe(II)/PMS and Mn(II)/NTA/PMS processes.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）