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Updated: Jun 8, 2026

Biogas Purification through the use of a Microalgae-Bacterial System in Semi-Industrial High Rate Algal Ponds
Published on: March 22, 2024
Nitrogen transformations under different conditions in open ponds by means of microalgae-bacteria consortium treating
Cristina González-Fernández1, Beatriz Molinuevo-Salces, Maria Cruz García-González
1Agricultural Technological Institute of Castilla and Leon, Ctra. Burgos km. 119, 47071 Valladolid, Spain. cgonfer@iq.uva.es
Abstract:
Four open ponds inoculated with microalgae-bacteria consortium treating different swine slurries (fresh and anaerobically digested) were evaluated in terms of nitrogen transformation under optimal and real conditions of temperature and illumination. Ammonium complete depletion was not achieved. Ponds operated under real conditions presented lower ammonium removal. Elimination capacities were around 26 mg N/Ld and were subsequently increased with increasing inlet ammonium loading rate. Different nitrogen transformation was observed depending on substrate source. When anaerobically digested slurry was fed to the ponds, nitrification followed by biomass uptake and denitrification were the main nitrogen transformation taking place depending on inlet ammonium loading rate and operational conditions. Ponds fed with fresh slurry exhibited denitrification as the main nitrogen removal mechanism for the pond operated under real conditions while under optimal conditions stripping, denitrification and biomass uptake contributed similarly. Therefore, this study confirmed that the so-claimed nitrogen recovery by microalgae biomass is frequently overestimated.
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