Dechlorination of chlorinated organic pollutants and methanogenesis are attractive biocathode reductions in microbial electrolysis cells (MECs). Quorum sensing (QS) is applied to regulate microbial communications. However, how acyl-homoserine lactones (AHLs)-dependent QS organize the assembly of the biocathode microbial community, and then regulate multiple biocathode reductions remains unclear. By applying N-butanoyl homoserine lactone (C4-HSL), N-hexanoyl homoserine lactone (C6-HSL) and 3-oxo-hexanoyl homoserine lactone (3OC6-HSL) in γ-hexachlorocyclohexane (γ-HCH) contaminated MECs, this study investigated the changes of biofilm microbial structure and function and the mechanisms of AHLs-QS on γ-HCH dechlorination and CH production. Exogenous C4-HSL and 3OC6-HSL increased cytochrome c production and enriched dechlorinators, electroactive bacteria but not methanogens to accelerate γ-HCH dechlorination and inhibit CH production. C6-HSL facilitated dechlorination and CH production by enhancing biofilm electroactivity and increasing membrane transportation. Besides, exogenous C6-HSL restored the electron transfer capacity that was damaged by the concurrent addition of acylase, an endogenous AHL quencher. From the perspective of microbial assembly, this study sheds insights into and provides an efficient strategy to selectively accelerate dechlorination and CH production by harnessing microbial structure based on QS systems to meet various environmental demands.
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http://dx.doi.org/10.1016/j.envpol.2023.122357 | DOI Listing |
Environ Pollut
January 2025
Department of Plant and Environmental Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark. Electronic address:
Nitrogen (N) doping of biomass prior pyrolysis has been identified as an effective approach for enhancing biochar catalytic reactivity. However, high-temperature pyrolysis of N-rich biomass may produce N-devoid biochars with high reactivity, calling for attention to the true causes of the reactivity increases and the role of nitrogen. In this study, N-doped wheat straw biochar (N-BC) materials were produced using urea as N dopant and different pyrolysis conditions, and their catalytic reactivity assessed for the reduction of trichloroethylene (TCE) by green rust (GR), a layered Fe(II)Fe(III) hydroxide.
View Article and Find Full Text PDFSmall
January 2025
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai, 200093, P. R. China.
Chlorophenols are difficult to degrade and mineralize by traditional advanced oxidation processes due to the strong electronegativity of chlorine. Here, a dual-site atomically dispersed catalyst (FeMoNC) is reported, which Fe/Mo supported on mesoporous nitrogen-doped carbon is prepared through high-temperature migration. The FeMoNC exhibits a high dechlorination rate of 93.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
Designing catalysts with both activity and stability remains a grand challenge for the removal of chlorinated volatile organic compounds (CVOCs) by catalytic oxidation. Herein, the Ru-Mn subnanometric species encapsulated in ZSM-5 zeolite (RuMn@Z) was synthesized. It shows that the 90% conversion of dichloromethane is as low as 320 °C, which is significantly lower than that of Ru@Z (350 °C) and the impregnation catalyst (RuMn/Z, 355 °C).
View Article and Find Full Text PDFJ Hazard Mater
January 2025
College of Water Sciences, Beijing Normal University, Beijing 100875, China; Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai 519087, China; National University of Singapore, Department of Civil and Environmental Engineering, 1 Engineering Drive 2, 117576, Singapore. Electronic address:
The extensive use of the antimicrobial compound chlorhexidine (CHD) has emerged as a significant threat to both the ecological environment and human health. To address this concern, a photo-electrochemical cell-microbial fuel cell (PMFC) system was studied for CHD removal by incorporating, for the first time, the photocatalysts black phosphorus/carbon nitride (BPCN) and CuO into the bioanode and air cathode of an MFC, respectively. By combining electrochemical, macro-genomic, and intermediate product analyses, the underlying mechanisms of bioelectronic and photoelectronic synergies were elucidated.
View Article and Find Full Text PDFChemosphere
January 2025
Department of Civil and Environmental Engineering, University of Massachusetts Lowell, Massachusetts, United States. Electronic address:
There is significant interest in monitoring abiotic decomposition of chlorinated solvents at contaminated sites due to large uncertainties regarding the rates of abiotic attenuation of trichloroethylene (PCE) and perchloroethylene (PCE) under field conditions. In this study, an innovative passive sampling tool was developed to quantify acetylene, a characteristic product of abiotic reduction of TCE or PCE, in groundwater. The sampling mechanism is based on the highly specific and facile click reaction between acetylene and an azide compound to form a biologically and chemically stable triazole product.
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