The effect of temperature on selenium (Se) removal by upflow anaerobic sludge blanket (UASB) reactors treating selenate and nitrate containing wastewater was investigated by comparing the performance of a thermophilic (55 °C) versus a mesophilic (30 °C) UASB reactor. When only selenate (50 μM) was fed to the UASB reactors (pH 7.3; hydraulic retention time 8 h) with excess electron donor (lactate at 1.38 mM corresponding to an organic loading rate of 0.5 g COD L(-1) d(-1)), the thermophilic UASB reactor achieved a higher total Se removal efficiency (94.4 ± 2.4%) than the mesophilic UASB reactor (82.0 ± 3.8%). When 5000 μM nitrate was further added to the influent, total Se removal was again better under thermophilic (70.1 ± 6.6%) when compared to mesophilic (43.6 ± 8.8%) conditions. The higher total effluent Se concentration in the mesophilic UASB reactor was due to the higher concentrations of biogenic elemental Se nanoparticles (BioSeNPs). The shape of the BioSeNPs observed in both UASB reactors was different: nanospheres and nanorods, respectively, in the mesophilic and thermophilic UASB reactors. Microbial community analysis showed the presence of selenate respirers as well as denitrifying microorganisms.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.watres.2016.02.007 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Programa de Pós-Graduação Em Saneamento, Meio Ambiente E Recursos Hídricos, Departamento de Engenharia Sanitária E Ambiental, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Belo Horizonte, MG, 31270-901, Brazil.
Wastewater treatment plants (WWTPs) currently face major challenges toward the removal of microcontaminants and/or microbial matrices and consequently play an important role in the potential dissemination of biological resistance in freshwater. The ultraviolet (UV) system is a tertiary treatment strategy increasingly applied worldwide, although many studies have shown that disinfected effluent can still contain antibiotic-resistant bacteria and resistance genes. Therefore, to better understand the effects of UV radiation doses on the removal of all resistance elements (antibiotics, antibiotic-resistant bacteria, and antibiotic resistance genes), the present study was designed using a pilot-scale photoreactor.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Sanitary Engineering Laboratory, Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 9 Iroon Polytechniou St., Zographou Campus, 15773, Athens, Greece.
Vertical subsurface flow constructed wetlands (VSSF CWs) were employed to investigate the use of biochar that could be produced with local agricultural biomass through pyrolysis, recycled glass from local recycling companies and gel beads with decreased packing volume and shipping cost as substrate alternatives to sand. The materials were assessed in terms of granulometry, porosity, adsorption capacity and hydraulic conductivity and were used for the treatment of an upflow anaerobic sludge blanket (UASB) reactor, treating domestic wastewater, effluent. Granulometry was a major factor impacting TSS removal that ranged from 81% ± 10% to 97% ± 2%.
View Article and Find Full Text PDFBioresour Bioprocess
January 2025
Biotechnology Processes Unit, IMDEA Energy, Avda. Ramón de la Sagra 3, Móstoles, Madrid, 28935, Spain.
This research investigated the acidogenic fermentation (AF) of sugar cane molasses in an up-flow anaerobic sludge blanket (UASB) reactor for the production of carboxylates. The first step was to assess the optimum process temperature (25, 35 or 55 ºC) using two different granular inocula, one from a brewery company (BGS) and other from a paper plant company (PGS). These experiments determined that the most suitable temperature for carboxylates production was 25 ºC, obtaining higher bioconversions (27.
View Article and Find Full Text PDFWater Res
January 2025
Department of Civil and Environmental Engineering, University of Florence, Via di S. Marta, 3, 50139, Firenze, Italy.
The performance of Upflow Anaerobic Sludge Blanket (UASB) bioreactors treating sulfate (SO) -rich effluents depends on multiple factors, including microbial interactions and operational conditions. The high complexity of these systems necessitates the use of mathematical modelling tools to better understand the process and predict the long-term impacts of various operational variables. In this work, a mathematical model describing the long-term operation of a sulfate-fed 2.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Technology Innovation Center for Food Safety Surveillance and Detection (Hainan), Sanya Institute of China Agricultural University, Sanya 572025, China; National Key Laboratory of Veterinary Public Health Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China. Electronic address:
Swine farm wastewater is a major reservoir of antimicrobial resistance genes (ARGs). Anaerobic digestion (AD), widely implemented in farms, has been extensively studied for ARG removal. However, a comparative study on ARG removal efficiency across the four principal AD systems - up-flow anaerobic sludge blanket (UASB), continuous stirred tank reactor (CSTR), buried biogas digester (BBD), and septic tank (SPT) - is lacking.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!