A start-up experiment was performed in a laboratory-scale, upflow anaerobic sludge blanket (UASB) reactor using seed sludge from a domestic waste treatment plant at 3.8-33.3gCODl(-1)day(-1) loading rates. Analysis over the height of the reactor with time showed that the VSS in the reactor was initially differentiated into active and non-active biomass at increasing gas production and upflow velocities, and specific update rates of the volatile fatty acids (VFA) components were pronounced at the bottom 10% of the reactor. During start-up, specific methanogenic activity and chemical oxygen demand (COD) uptake rate increased from 0.075 to 0.75gCOD-CH4(gVSS)(-1)day(-1) and from 0.08 to 0.875gCOD removed (gVSS)(-1)day(-1), respectively. When seed sludge from a distillery waste treatment plant was used, improved performance due to a predominance of active biomass was evident when the loading rate was increased from 9.4 to 28.7gCODl(-1)day(-1). The proposed start-up evaluation is an effective tool to successfully monitor performance of UASB reactors.
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http://dx.doi.org/10.1016/j.biortech.2008.03.011 | 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.
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