This study describes the change of organic degradation capability and soluble microbial products (SMP) generated in activated sludge under continuous exposure to Zn (II) in a sequencing batch reactor (SBR). In 338 days of operation, the added Zn (II) concentrations were gradually increased from 50 to 100, 200, 400 to 600 and 800 mg/L. Results showed that after adaptation, the activated sludge could endure 400mg/L Zn (II) without showing evident reduction in organic degradation ability (92±1% of chemical oxygen demand (COD) removal in stable state). However, when 600 and 800 mg/L Zn (II) were applied, the effluent water quality significantly deteriorated. Meanwhile, under increasing Zn (II) concentrations, the SMP content in the activated sludge, together with its main biochemical constituents, first increased slightly below 400mg/L of Zn (II), then rose sharply under 600 and 800 mg/L Zn (II). Furthermore, a close correlation was found between SMP content and effluent soluble COD in both the Experimental Reactor and Control Reactor. In addition, the Zn (II) concentrations in the effluent and SMP extraction liquid were further analyzed and discussed to reveal the role that SMP constituents played in defense and resistance to the toxicity of Zn (II).
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http://dx.doi.org/10.1016/j.jhazmat.2012.10.065 | DOI Listing |
Environ Res
January 2025
Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, P.R. China.
Herein, a biochar-supported zero-valent iron (ZVI) nanosheet catalyst (Fe@BC) for the activation of persulfate to degrade ciprofloxacin (CIP) was prepared using industrial kraft lignin and Fenton sludge as carbon and iron sources, respectively. Fe@BC showed considerably better CIP degradation efficiency (96.9% at 20 mg·L) than traditional catalysts.
View Article and Find Full Text PDFWater Res
December 2024
Deptartment of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft, HZ 2629, the Netherlands; Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark.
Extracellular Polymeric Substances (EPS) are ubiquitous in biological wastewater treatment (WWT) technologies like activated sludge systems, biofilm reactors, and granular sludge systems. EPS recovery from sludge potentially offers a high-value material for the industry. It can be utilized as a coating in slow-release fertilizers, as a bio-stimulant, as a binding agent in building materials, for the production of flame retarding materials, and more.
View Article and Find Full Text PDFAppl 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 PDFEnviron Microbiol
January 2025
DTU Aqua, Section for Aquaculture, Technical University of Denmark, Hirtshals, Denmark.
The unintended microbiological production of hydrogen sulphide (HS) poses a significant challenge in engineered systems, including sewage treatment plants, landfills and aquaculture systems. Although sulphur-rich amino acids and other substrates conducive to non-sulphate-based HS production are frequently present, the capacity and potential of various microorganisms to perform sulphate-free HS production remain unclear. In this study, we identify the identity, activity and genomic characteristics of bacteria that degrade cysteine to produce HS in anaerobic enrichment bioreactors seeded with material from aquaculture systems.
View Article and Find Full Text PDFSci Total Environ
January 2025
CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; LABBELS - Associate Laboratory, Guimarães, Braga, Portugal. Electronic address:
The conversion of organic matter to methane through anaerobic digestion (AD) process can be enhanced by different materials. However, literature reports show inconsistent results on the effect of materials in different AD systems. In this study, we evaluated the influence of the inoculum's activity on methane production (MP) efficiency in the presence of different materials (activated carbon (AC), magnetite (Mag), and zeolite (Zeo)).
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