Perfluorooctanoic acid (PFOA), as a recalcitrant organic pollutant, inevitably enters wastewater treatment facilities and is enriched in settled sludge. However, the potential impact of PFOA on sludge treatment has never been documented. In this study, the effect of PFOA on anaerobic digestion of sewage sludge and its underlying mechanism were investigated through batch and long-term experiments. The presence of PFOA was found to be deleterious for methane production from sewage sludge. 170 mg/kg total solids PFOA reduced the cumulative methane production from 197.1 ± 1.92-159.9 ± 3.10 mL/g volatile solids. PFOA induces the production of reactive oxygen species, which directly leads to cell inactivation and interferes with methane production. PFOA stimulates microorganisms to secrete more extracellular polymeric substances (mainly proteins), which not only hinders the solubilization of organic matter but also down-regulate enzyme activities to inhibit acidification and methanogenesis. In addition, PFOA reduces the diversity of microorganisms, especially the abundance of acid-producing bacteria and methanogens, making the microbial community unfavorable for methane production.
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http://dx.doi.org/10.1016/j.jhazmat.2021.127418 | DOI Listing |
Environ Monit Assess
January 2025
Laboratory for Ecotoxicology and Environmental Forensics, University of Benin, PMB 1154, Benin City, Nigeria.
This research was carried out to assess the concentrations of carbon monoxide (CO) and formaldehyde (HCHO) in Edo State, Southern Nigeria, using remote sensing data. A secondary data collection method was used for the assessment, and the levels of CO and HCHO were extracted annually from Google Earth Engine using information from Sentinel-5-P satellite data (COPERNISCUS/S5P/NRTI/L3_) and processed using ArcMap, Google Earth Engine, and Microsoft Excel to determine the levels of CO and HCHO in the study area from 2018 to 2023. The geometry of the study location is highlighted, saved and run, and a raster imagery file of the study area is generated after the task has been completed with a 'projection and extent' in the Geographic Tagged Image File Format (.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Department of General Physics, Kazan National Research Technical University Named After A.N. Tupolev-KAI, Kazan 420111, Russia.
In this work, within the framework of a self-consistent model of arc discharge, a simulation of plasma parameters in a mixture of argon and methane was carried out, taking into account the evaporation of the electrode material in the case of a refractory and non-refractory cathode. It is shown that in the case of a refractory tungsten cathode, almost the same methane conversion rate is observed, leading to similar values in the density of the main methane conversion products (C, C, H) at different values of the discharge current density. However, with an increase in the current density, the evaporation rate of copper atoms from the anode increases, and a jump in the - characteristic is observed, caused by a change in the plasma-forming ion.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Agriculture and Agri-Food Canada, Quebec Research and Development Centre, Quebec, QC G1V 2J3 Canada.
This study examined the effects of supplementing dairy cows with a mixture of essential oils on enteric CH emissions, apparent total-tract nutrient digestibility, N utilization, and lactational performance (production, components and efficiency). Thirty-two multiparous lactating Holstein cows were used in a randomized complete block design. Cows averaged (mean ± SD) 95 ± 15.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Murdoch University, Murdoch, WA, 6150, Australia. Electronic address:
Reducing enteric methane emissions from livestock is a key environmental challenge, as methane is a major pollutant. The complexity of animal biology and diverse diet compositions make it difficult to develop strategy to control methane production. This study examined the use of plant phenolic extracts of Madhuca longifolia (ML-7) as a feed additive combined with various ruminant diets and dosages to find an effective supplement to reduce methane emissions.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
E2Lim - Eau et Environnement Limoges UR 24133, University of Limoges, Limoges, France.
Excess of trace elements (TE) significantly alters the performances of anaerobic digestors (AD). Due to interactions with organic matter in particular, only a small fraction of TE can effectively interact with the biomass. However, assessing the bioavailable fraction of TE remains an issue.
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