1. Changes in bacteria composition and efficiency of constructed wetlands under sustained overloads: A modeling experiment
- Author
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Joan García, Anacleto Rizzo, Fulvio Boano, Luca Ridolfi, Roger Samsó, Roberto Revelli, DEPARTMENT OF ENVIRONMENT LAND AND INFRASTRUCTURE ENGINEERING POLITECNICO DI TORINO TURIN ITA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), IRIDRA SRL FLORENCE ITA, Réduire, valoriser, réutiliser les ressources des eaux résiduaires (UR REVERSAAL), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), GEMMA ENVIRONMENTAL ENGINEERING AND MICROBIOLOGY GROUP DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING UNIVERSITAT POLITECNICA DE CATALUNYA BARCELONA ESP, DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING DUKE UNIVERSITY DURHAM USA, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, and Universitat Politècnica de Catalunya. GEMMA - Grup d'Enginyeria i Microbiologia del Medi Ambient
- Subjects
Environmental Engineering ,CONSTRUCTED WETLAND ,Zones humides artificials ,0208 environmental biotechnology ,ORGANIC LOAD ,Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament de l'aigua [Àrees temàtiques de la UPC] ,Biomass ,Wetland ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Clogging ,Hydraulic load ,Environmental Chemistry ,Effluent ,Waste Management and Disposal ,BUFFERING CAPACITY ,0105 earth and related environmental sciences ,geography ,BIO_PORE ,Buffering capacity ,Constructed wetland ,Organic load ,Pollution ,geography.geographical_feature_category ,Constructed wetlands ,Environmental engineering ,15. Life on land ,020801 environmental engineering ,13. Climate action ,[SDE]Environmental Sciences ,HYDRAULIC LOAD ,Environmental science - Abstract
International audience; The average organic and hydraulic loads that Constructed Wetlands (CWs) receive are key parameters for their adequate long-term functioning. However, over their lifespan they will inevitably be subject to either episodic or sustained overloadings. Despite that the consequences of sustained overloading are well known (e.g., clogging), the threshold of overloads that these systems can tolerate is difficult to determine. Moreover, the mechanisms that might sustain the buffering capacity (i.e., the reduction of peaks in nutrient load) during overloads are not well understood. The aim of this work is to evaluate the effect of sudden but sustained organic and hydraulic overloads on the general functioning of CWs. To that end, the mathematical model BIO_PORE was used to simulate five different scenarios, based on the features and operation conditions of a pilot CW system: a control simulation representing the average loads; 2 simulations representing +10% and +30% sustained organic overloads; one simulation representing a sustained +30% hydraulic overload; and one simulation with sustained organic and hydraulic overloads of +15% each. Different model outputs (e.g., total bacterial biomass and its spatial distribution, effluent concentrations) were compared among different simulations to evaluate the effects of such operation changes. Results reveal that overloads determine a temporary decrease in removal efficiency before microbial biomass adapts to the new conditions and COD removal efficiency is recovered. Increasing organic overloads cause stronger temporary decreases in COD removal efficiency compared to increasing hydraulic loads. The pace at which clogging develops increases by 10% for each 10% increase on the organic load.
- Published
- 2018