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The co-contamination of hexavalent chromium (Cr(VI)) and ammonium (NH-N) in industrial wastewater has attracted considerable attention due to its serious threats to both ecological systems and public health. Manganese(IV) (Mn(IV))-driven NH-N oxidation (Mnammox) coupled with Mn(II)-mediated denitrification (MnOD), built on the Mn redox cycle, is a promising nitrogen removal process, where Mn(II) and NO-N generated during Mnammox were effectively controlled by MnOD. Herein, a bioreactor integrating Mnammox and MnOD for NH-N and Cr(VI) removal was constructed utilizing core-shell gel beads embedded with two core strains and δ-MnO. When the C/N was 1.5, pH was 6.5, and HRT was 20 h, the removal efficiencies for Cr(VI) and NH-N reached 96.3 and 91.3 %, respectively. Cr(VI) can be bioreduced to Cr(III) in bioreactors. Additionally, the microbial activity and electron transfer properties in the Mn redox system were studied under varying Cr(VI) concentrations. High-throughput data revealed that high Cr(VI) concentrations significantly impacted microbial community diversity, while Aromatoleu and Zoogloea consistently remaining the dominant species in the bioreactor. KEGG database analysis showed that appropriately increasing C/N promoted the expression of genes related to nitrification and Mn redox cycling. This study provides novel perspectives on the application of the Mnammox coupled MnOD process driven by the Mn redox cycle for treating NH-N and Cr(VI) co-contaminated industrial wastewater.
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http://dx.doi.org/10.1016/j.watres.2025.123713 | DOI Listing |
Environ Sci Technol
September 2025
Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Iron plaque (IP) on rice root surfaces has been extensively documented as a natural barrier that effectively reduces contaminant bioavailability and accumulation. However, its regulatory mechanisms in rhizospheric methane oxidation and biological nitrogen fixation (BNF) remain elusive. This study reveals a previously unrecognized function of IP: mediating methanotrophic nitrogen fixation through coupled aerobic methane oxidation and IP reduction (Fe-MOX).
View Article and Find Full Text PDFLangmuir
September 2025
Key Laboratory of Functional Molecular Solids (Ministry of Education), College of Chemistry and Materials Science, Anhui Key Laboratory of Biomedical Materials and Chemical Measurement, Anhui Normal University, Wuhu 241000, China.
The sluggish kinetics and diffusion of lithium polysulfide (LiPS) intermediates lead to the decline in the capacity and rate of high-energy lithium-sulfur (Li-S) batteries. Integrating adsorbents and electrocatalysts into the Li-S system is an effective strategy for suppressing the polysulfide shuttle and enhancing the redox kinetics of sulfur species. The disordered structure of the electrocatalysts exhibits significantly enhanced catalytic activity.
View Article and Find Full Text PDFFront Pharmacol
August 2025
Shenzhen Institute for drug Control, Shenzhen, China.
Introduction: The procedural complexity and time-consuming of conventional pesticide residue detection methods in traditional Chinese medicines (TCMs) significantly impeded their application in modern systems. To address this, this study presented an innovative dual-mode sensor driven by Cu/Cu redox-cycling, which achieved efficient signal transduction from enzyme inhibition to optical response for rapid acetylcholinesterase (AChE) activity and organophosphorus pesticide (OP) residue detection.
Methods: The AB-Cu NPs sensor, a dynamic redox-responsive system, was constructed via coordination-driven assembly of Azo-Bodipy 685 (AB 685) and Cu.
Angew Chem Int Ed Engl
September 2025
College of Materials Science and Opto-electronic Technology, Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
High-voltage operation enables sodium-sufficient O3-type layered oxides to approach the maximum achievable energy densities for practical sodium-ion batteries (SIBs). This high-voltage regime, however, induces structural degradation strongly correlated with oxygen redox activity, a mechanism still incompletely resolved. Using prototypical O3-type NaNiFeMnO (NFM) as a model system, we identify the origin of this instability as a detrimental feedback loop between σ-type oxygen redox and cation migration.
View Article and Find Full Text PDFWater Res
August 2025
College of Environment and Ecology, Chongqing University, Chongqing 400045, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400045, China. Electronic address:
This study explores the role of α-Fe₂O₃ in improving extracellular electron transfer (EET) and symbiotic interactions between electroactive Shewanella oneidensis MR-1, its gene-deficient mutants (ΔmtrC, ΔomcA, and ΔcymA), and microalgae (Chlorella vulgaris). The iron oxide facilitates the efficient transfer of electrons generated by MR-1 to microalgal photosystem via the pathway of CymA-MtrC-OmcA to α-Fe₂O₃. This process enhances the removals of TOC, TN, and NH₄⁺-N in the MR-1 bacterial-algal consortium by 9.
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