Title:
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Effects of partially saturated conditions on the metabolically active microbiome and on nitrogen removal in vertical subsurface flow constructed wetlands
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Author:
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Pelissari, Catiane; Guivernau Ribalta, Miriam; Viñas, Marc; García Serrano, Joan
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Other authors:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental; Universitat Politècnica de Catalunya. GEMMA - Grup d'Enginyeria i Microbiologia del Medi Ambient |
Abstract:
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Nitrogen dynamics and its association to metabolically active microbial populations were assessed in two vertical subsurface vertical flow (VF) wetlands treating urban wastewater. These VF wetlands were operated in parallel with unsaturated (UVF) and partially saturated (SVF) configurations. The SVF wetland exhibited almost 2-fold higher total nitrogen removal rate (5 g TN m−2 d−1) in relation to the UVF wetland (3 g TN m−2 d−1), as well as a low NOx-N accumulation (1 mg L−1 vs. 26 mg L−1 in SVF and UVF wetland effluents, respectively). After 6 months of operation, ammonia oxidizing prokaryotes (AOP) and nitrite oxidizing bacteria (NOB) displayed an important role in both wetlands. Oxygen availability and ammonia limiting conditions promoted shifts on the metabolically active nitrifying community within ‘nitrification aggregates’ of wetland biofilms. Ammonia oxidizing archaea (AOA) and Nitrospira spp. overcame ammonia oxidizing bacteria (AOB) in the oxic layers of both wetlands. Microbial quantitative and diversity assessments revealed a positive correlation between Nitrobacter and AOA, whereas Nitrospira resulted negatively correlated with Nitrobacter and AOB populations. The denitrifying gene expression was enhanced mainly in the bottom layer of the SVF wetland, in concomitance with the depletion of NOx-N from wastewater. Functional gene expression of nitrifying and denitrifying populations combined with the active microbiome diversity brought new insights on the microbial nitrogen-cycling occurring within VF wetland biofilms under different operational conditions. |
Subject(s):
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-Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament de l'aigua -Constructed wetlands -Sewage--Purification--Nitrogen removal -Partial saturation
Nitrifying-denitrifying prokaryotes
Nitrification-aggregates
Metabolically active microbiome
Nitrogen metabolism -Zones humides artificials -Aigües residuals--Depuració--Desnitrificació |
Rights:
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Document type:
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Article - Published version Article |
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