Aerobic methanotrophs can contribute to nitrate removal from contaminated waters, wastewaters, or landfill leachate by assimilatory reduction and by producing soluble organics that can be utilized by coexisting denitrifiers. The goal of this study was to investigate nitrate removal and biofilm characteristics in membrane biofilm reactors (MBfR) with various supply regimes of oxygen and methane gas. Three MBfR configurations were developed and they achieved significantly higher nitrate removal efficiencies in terms of methane utilization (values ranging from 0.25 to 0.36molNmol(-1)CH(4)) than have previously been observed with suspended cultures. The biofilm characteristics were investigated in two MBfRs with varying modes of oxygen supply. The biofilms differed in structure, but both were dominated by Type I methanotrophs growing close to the membrane surface. Detection of the nitrite reductase genes, nirS and nirK, suggested genetic potential for denitrification was present in the mixed culture biofilms.
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http://dx.doi.org/10.1016/j.watres.2009.09.009 | DOI Listing |
J Hazard Mater
January 2025
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address:
Nitrate pollution poses severe risks to aquatic ecosystems and human health. The electrocatalytic nitrate reduction reaction (NITRR) offers a promising environmental and economic solution for nitrate pollution treatment and nitrogen source recovery; however, it continues to experience limited efficiency in neutral electrolytes. This study explores the heterointerface activation effects of TiO/CuO heterogeneous catalysts with rutile (R-TiO) and anatase (A-TiO) phases and reveals that R-TiO is an active crystal phase with high nitrate reduction performance.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA.
Discharge of wastewater containing nitrate (NO) disrupts aquatic ecosystems even at low concentrations. However, selective and rapid reduction of NO at low concentration to dinitrogen (N) is technically challenging. Here, we present an electrified membrane (EM) loaded with Sn pair-atom catalysts for highly efficient NO reduction to N in a single-pass electrofiltration.
View Article and Find Full Text PDFEnviron Technol
January 2025
Botany Discipline, School of Biological Sciences and Biotechnology, Goa University, Goa, India.
The dairy industry is a significant sector within the food industries, known for its high-water consumption and consequent generation of dairy wastewater (DWW), which is rich in pollutants like Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). Improper disposal of DWW poses serious environmental challenges, including eutrophication and highlighting the need for sustainable biological treatment methods. This study investigates the potential of indigenous cyanobacterial strains , , , and for the bioremediation of DWW.
View Article and Find Full Text PDFEnviron Microbiol
January 2025
Faculty of Biology-Microbiology, University of Freiburg, Freiburg, Germany.
Bacterial degradation of ubiquitous and persistent steroids such as steroid hormones is important for their removal from the environment. Initial studies of steroid degradation in anaerobic bacteria suggested that ring-cleaving hydrolases are involved in oxygen-independent sterane skeleton degradation. However, the enzymes involved in ring A cleavage of the common intermediate androsta-1,4-diene-3,17-dione have remained unknown.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, School of Geographical Sciences, Harbin Normal University, Harbin, 150025, China; Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, Harbin, 150025, China. Electronic address:
Nitrogen and phosphorus inputs to surface water bodies lead to a decline in water quality and a disruption in the balance of aquatic ecosystems. Emergent aquatic plants were widely used for their high efficiency in removing nitrogen and phosphorus from surface waters. However, there was a lack of systematic analyses on the purification of surface waters by emergent aquatic plants, and the mechanism of differences in nitrogen and phosphorus removal by different plants needs to be further revealed.
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