Power output limitation is one of the main concerns that need to be addressed for full-scale applications of the microbial fuel cell technology. Fouling and biofilm growth on the cathode of single chamber microbial fuel cells (SCMFC) affects their performance in long-term operation with wastewater. In this study, the authors report the power output and cathode polarization curves of a membraneless SCMFC, fed with raw primary wastewater and sodium acetate for over 6 months. At the end of the experiment, the whole cathode surface is analyzed through X-ray microcomputed tomography (microCT), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) to characterize the fouling layer and the biofilm. EDX shows the distribution of Ca, Na, K, P, S, and other elements on the two faces of the cathode. Na-carbonates and Ca-carbonates are predominant on the air (outer) side and the water (inner) side, respectively. The three-dimensional reconstruction by X-ray microCT shows biofilm spots unevenly distributed above the Ca-carbonate layer on the inner (water) side of the cathode. These results indicate that carbonates layer, rather than biofilm, might lower the oxygen reduction reaction rate at the cathode during long-term SCMFC operation.
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http://dx.doi.org/10.1116/1.4930239 | DOI Listing |
Environ Sci Technol
December 2024
Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California 90095, United States.
Wetland methane emissions are the primary natural contributor to the global methane budget, accounting for approximately one-third of total emissions from natural and anthropogenic sources. Anaerobic oxidation of methane (AOM) serves as the major sink of methane in anoxic wetland sediments, where electron acceptors are present, thereby effectively mitigating its emissions. Nevertheless, environmental controls on electron acceptors, in particular, the ubiquitous iron oxides, involved in AOM are poorly understood.
View Article and Find Full Text PDFSurgery
December 2024
Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, NC; Department of Medicine (Endocrinology), Duke University School of Medicine, Durham, NC.
Objective: To characterize early physiologic stresses imposed by surgery by applying metabolomic analyses to deeply phenotype pre- and postoperative plasma and urine of patients undergoing elective surgical procedures.
Background: Patients experience perioperative stress through depletion of metabolic fuels. Bowel stasis or injury might allow more microbiome-derived uremic toxins to enter the blood, while the liver and kidney are simultaneously clearing analgesic and anesthetic drugs.
JACS Au
December 2024
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States.
In the past decade, conjugated oligoelectrolytes (COEs) and conjugated polyelectrolytes (CPEs) have emerged at the forefront of active materials in bioanalytical and electrochemical settings due to their unique electronic and ionic properties. These materials possess π-conjugated backbones with ionic functionalities at the ends of their side chains, granting them water solubility and facilitating their processability, exploration, and applications in aqueous environments. In this perspective, the basis for evaluating their figures of merit in selected bioanalytical and electrochemical contexts will be provided and contextualized.
View Article and Find Full Text PDFWater Res
December 2024
Xiamen Key Laboratory of Municipal and Industrial Solid Waste Utilization and Pollution Control, College of Civil Engineering, Huaqiao University, Xiamen, Fujian 361021, PR China; Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, 130118, PR China. Electronic address:
As freshwater demand grows globally, using reclaimed water in natural water bodies has become essential. Constructed wetlands (CWs) are widely used for advanced wastewater treatment due to their environmental benefits. However, low carbon/nitrogen (C/N) ratios in wastewater limit nitrogen removal, often leading to eutrophication.
View Article and Find Full Text PDFBioelectrochemistry
December 2024
School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353 Shandong, PR China; State Key Laboratory of Bio-based Materials and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, PR China. Electronic address:
Sediment microbial fuel cell (SMFC) is a device for biological denitrification, in which electrons produced by sediment microorganisms can be transferred to the upper layer of the water column lacking electron donors. However, the low efficiency of denitrifying bacteria in acquiring electrons and enriching at the cathode greatly hinders the application of SMFC for nitrogen removal. In this study, we report a novel method of constructing a high-performance biocathode by modifying electrodes with zero-valent iron to enhance the enrichment and electron transfer of electroactive bacteria.
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