Removal of nitrogen from wastewater without using electricity consuming aerators was previously observed in photo-bioreactors with a mixed algal-bacterial biomass. Algammox is the particular process based on algae, ammonium oxidizing organisms and anammox bacteria. In this research the activity of anammox bacteria in such an oxygen-producing environment was tested, as well as the effect of short-duration increase in dissolved oxygen (DO) to values potentially inhibiting anammox activity. Sequencing batch photo-bioreactors were fed with settled domestic wastewater enriched with ammonium (200mgNH-N/L) and exposed to light within the photosynthetic active range with intensity of about 500μmol/m·s. Each cycle consisted of 12h illumination and 12h darkness. A well-settling biomass (10days solids retention time) developed that carried out nitritation, nitrification and anammox. Ammonium removal rate during the light period was 4.5mgN-NH/L·h, equal to 858mgN-NH/m·h or 477mgN-NH/(mol photons). When the reactors were aerated for 3h to temporarily increase the DO, anammox was inhibited at bulk DO values larger than 0.4-1.0mg/L. For almost oxygen saturated conditions, recovery time was about 9days. Algammox photo-bioreactors are therefore able to overcome short periods of oxygen stress, provided they occur only occasionally.
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http://dx.doi.org/10.1016/j.scitotenv.2018.04.082 | DOI Listing |
J Arthropod Borne Dis
June 2024
Department of Environment Health, Ardabil University of Medical Sciences, Ardabil, Iran.
Background: Water quality is usually measured using various indicators based on physical, chemical and biological parameters. By using the biological index that is based on the identification of the arthropod families, it is possible to make a logical judgment about the ecosystem condition. The aim of this study was measuring correlation coefficients between qualitative and biological Indices.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
Charosphere, a highly active zone between biochar and surrounding soil, is widely present in agricultural and wildfire-affected soils, yet whether reactive oxygen species (ROS) are produced within the charosphere remains unclear. Herein, the production and spatiotemporal evolution of charosphere ROS were explored. In situ ROS capture visualized a gradual decrease in ROS production with increasing distance from the biochar/soil interface.
View Article and Find Full Text PDFEnviron Res
January 2025
College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
Estuarine ecosystems have been threatened by increasing anthropogenic and natural pressures, yet the integral understanding of their stability characteristics of microbial communities at taxonomic, habitat, and spatial scales remains limited. In this study, the Mulan River estuary in southeastern China was selected to compare the stability characteristics of bacterial and protistan communities in water and sediments over three hydrological periods, and to explore their spatial variations along the estuarine continuum from river to ocean. The potential driving mechanisms of stability characteristics were also explored.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, Oeiras, 2780901, Portugal.
Generation of upscaled quantities of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), for therapeutic or testing applications, is both expensive and time-consuming. Herein, a scalable bioprocess for hiPSC-CM expansion in stirred-tank bioreactors (STB) is developed. By combining the continuous activation of the Wnt pathway, through perfusion of CHIR99021, within a mild hypoxia environment, the expansion of hiPSC-CM as aggregates is maximized, reaching 4 billion of pure hiPSC-CM in 2L STB.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Microbiology, Oregon State University, 220 Nash Hall, Corvallis, OR, USA.
Global oxygen minimum zones (OMZs) often reach hypoxia but seldom reach anoxia. Recently it was reported that Michaelis Menten constants (K) of oxidative enzymes are orders of magnitude higher than respiratory K values, and in the Hypoxic Barrier Hypothesis it was proposed that, in ecosystems experiencing falling oxygen, oxygenase enzyme activities become oxygen-limited long before respiration. We conducted a mesocosm experiment with a phytoplankton bloom as an organic carbon source and controlled dissolved oxygen (DO) concentrations in the dark to determine whether hypoxia slows carbon oxidation and oxygen decline.
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