The function of iron (ferric (Fe(III)) and ferrous (Fe(II))) in the hexavalent chromium (Cr(VI)) reduction mechanism by bacteria in municipal landfill leachate (MLL) was assessed. Evidence of an "electron shuttle" mechanism was observed, whereby the Cr(VI) was reduced to trivalent chromium (Cr(III)) by Fe(II) with the resulting Fe(III) bacterially re-reduced to Fe(II). Typically, investigations on this electron shuttle mechanism have been performed in an artificial medium. As MLL comprises an elaborate mixture of bacteria, humic materials and organic and inorganic species, additional complexities were evident within the cycle in this study. Bioavailability of the Fe(III) for bacterial reduction, availability of bacterially produced Fe(II) for chemical Cr(VI) reduction and hydrolysis of Fe(II) and Fe(III) become prevalent during each phase of the shuttle cycle when MLL is present. Each of these factors contributes to the overall rate of bacterial Cr(VI) reduction in this media. This work highlights the need to consider local environmental conditions when assessing the bacterial reduction of Cr(VI).
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http://dx.doi.org/10.1016/j.jhazmat.2008.04.007 | DOI Listing |
This work aimed at addressing the problem of hexavalent chromium pollution in the water environment, designing and preparing the Cu/CuO/NH-MIL-88B (Fe) heterojunction material with NH-MIL-88B (Fe) as the carrier, Cu/CuO was loaded on NH-MIL-88B (Fe) by light-assisted reduction. The loading of CuO effectively improves the visible light absorption capacity of the composite material. The SPR effect of Cu improves the separation and transfer of photogenerated carriers in the composite material.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China. Electronic address:
Traditionally, abiotic factors such as pH, temperature, and initial Cr(VI) concentration have been undoubtedly recognized as the external driving forces that dramatically affect the microbial-mediated remediation of Cr(VI) pollutants. However, concentrating on whether and how the biological behaviors and metabolic activities drive the microbial-mediated Cr(VI) detoxification is a study-worthy but little-known issue. In this study, Leucobacter chromiireducens CD49 isolated from heavy-metal-contaminated soil was identified to tolerate 8000.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Environmental Science and Engineering, Fuzhou University, Minhou, Fujian 350108, China.
Environmental concerns are driving the development of eco-friendly and effective methods for contaminant monitoring and remediation. In this study, a lanthanide porphyrin-based MOF with dual fluorescence sensing and photocatalytic properties was synthesized and applied for the detection and combined removal of Cr(VI) and ciprofloxacin (CIP). Using different excitation wavelengths, the material exhibited selective detection of Cr(VI) via fluorescence quenching and CIP through fluorescence enhancement.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China. Electronic address:
Heterointerface engineering is an effective strategy to design and construct high-performance photocatalysts. Herein, polyaniline (PANI) nanoparticles and ZnTi layered double hydroxide (ZnTi-LDH) nanosheets were integrated to form organic-inorganic heterostructure (PANI/LDH) via d-π electronic coupling using in-situ polymerization for photocatalytic oxidation/reduction towards tetracycline (TC) and Cr(VI). The photocatalytic activity was closely related to feed amount of aniline (Ani) in the polymerization process, which the abundant PANI nanoparticles were evenly distributed on the surface of ZnTi-LDH nanosheets at the proper Ani feed amount, and thus reinforced d-π electronic coupling at the organic-inorganic interfaces more efficiently.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Mechatronics Engineering Department, School of Automobile, Mechanical and Mechatronics, Manipal University Jaipur, India. Electronic address:
Herein, novel hollow ZnO and ZnO@SnInS core-shell nanorods (NRs) with controlled shell thickness were developed via a facile synthesis approach for the efficient photocatalytic remediation of organic as well inorganic water pollutants. The introduction of SnInS shell layer coating over ZnO enhances visible light absorption, efficient exciton-mediated direct charge transfer, and reduces the band gap of ZnO@SnInS core-shell nanorods. The ZnO@SnInS core-shell nanorods show efficient solar-light driven catalytic efficiency for the disintegration of industrial dye (orange G), degradation of tetracycline, and reduction of hazardous Cr (VI) ions in aquatic systems.
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