Literature shows that full-scale pure-oxygen activated sludge (O2-AS) wastewater treatment plants (WWTPs) generate effluents with higher dissolved-organic carbon (DOC) concentrations and larger high-molecular-weight fractions compared to air-activated-sludge (Air-AS) WWTP effluents. The purpose of this paper was to evaluate how gas supplied (air vs. pure oxygen) to sequencing-batch reactors affected DOC transformations. The main conclusions of this paper are (a) O2-AS effluent DOC is more refractory than air-AS effluent DOC; and (b) O2-AS systems may have higher five-day biochemical oxygen demand removals than air-AS systems; however, in terms of COD and DOC removal, air-AS systems are better than O2-AS systems. Analysis of a database from side-by-side O2- and air-AS pilot tests from literature supported these observations.
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http://dx.doi.org/10.2175/106143005x94411 | DOI Listing |
Appl Biochem Biotechnol
January 2025
Department of Biotechnology-CBS, Metropolitan Autonomous University Iztapalapa, Av. Ferrocarril San Rafael Atlixco 186, 09310, Mexico City, Mexico.
The presence of antibiotics in wastewater discharges significantly affects the environment, mainly due to the generation of bacterial populations with multiple antibiotic resistances. The cometabolic capacity of nitrifying sludge to simultaneously remove ammonium (NH) and emerging organic contaminants (EOCs), including antibiotics, has been reported. In the present study, the removal capacity of 50 mg ampicillin (AMP)/L by nitrifying cultures associated with biosorption and biotransformation processes was evaluated in a sequencing batch reactor (SBR) system.
View Article and Find Full Text PDFBioresour Technol
January 2025
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Chemical Engineering, Ocean and Life Sciences, Dalian University of Technology, Panjin 124221, China. Electronic address:
Microplastics (MPs) are prevalent in wastewater treatment systems, and their behavior is further complicated after undergoing aging processes. This study explored the impact of original and aged polyvinyl chloride (PVC) MPs on wastewater treatment performance and bacterial communities. Results revealed that Fenton-aging treatment induced surface roughening of the MPs and altered their chemical properties.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Viona Consulting Inc, Agro-Environmental Innovation and Technology, Research and Development Company, Thornhill, ON, L3T 0C6, Canada.
Energy from renewable resources has been growing in popularity, which ultimately helps reduce emissions of greenhouse gases (GHGs) and contaminants. Since hydrogen (H) has a higher combustion production of energy than hydrocarbon fuels, it has been identified as a clean, sustainable, and environmentally friendly energy source. There are several benefits to producing biohydrogen (bioH) from renewable sources, including lower cost and increased sustainability.
View Article and Find Full Text PDFBioresour Technol
December 2024
School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310000, PR China; Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Hangzhou 310023, PR China.
This study introduces a technique utilizing natural pyrrhotite powder as a nucleating agent in four sequencing batch reactors (SBRs) for the treatment of dye wastewater. Through analysis of various factors including pH, pyrrhotite surface free energy, sludge zeta potential, and shifts in microbial communities, the mechanism by which pyrrhotite facilitates the formation of aerobic granular sludge (AGS) is elucidated. Over 140 days of continuous operation under neutral conditions, natural pyrrhotite rapidly cultivated AGS under neutral conditions.
View Article and Find Full Text PDFAppl Environ Microbiol
December 2024
Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
Unlabelled: During the coronavirus disease 2019 epidemic, excessive chlorine disinfectants have been used to block the spread of severe acute respiratory syndrome-coronavirus 2, resulting in large amounts of residual disinfectants entering wastewater treatment plants (WWTPs) through sewage systems. So far, no relevant research has been conducted on the impact of chlorine disinfectants on microfauna, an important microbial component in activated sludge treatment systems. This study comprehensively investigated the changes in microfauna habitat, community structure, and colonization mode under the chlorine stress by combining the full-scale WWTP survey and laboratory-scale sequencing batch reactor experiments.
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