Evaluación del Balance de Carbono en una Planta de Tratamiento de Aguas Residuales Basada en Humedales Artificiales

[EN] Constructed wetlands have demonstrated their usefulness in wastewater treatment as key tools in climate change mitigation actions by acting as carbon sinks. However, this capture capacity is offset by greenhouse gas (GHG) emissions generated during the bacterial decontamination processes that o...

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Autores: Mejía Peralta, Fernanda Estefanía, Benedito Durá, Vicent|||0000-0003-3203-0127, Hernández Crespo, Carmen|||0000-0002-6727-0481
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:español
OAI Identifier:oai:riunet.upv.es:10251/222496
Acceso en línea:https://riunet.upv.es/handle/10251/222496
Access Level:acceso abierto
Palabra clave:Constructed wetlands
Treatment
Wastewater
Greenhouse gases
Carbon balance
Methane
Nitrous oxide
Carbon dioxide
Sink
Humedales artificiales
Tratamiento
Aguas residuales
Gases efecto invernadero
Balance de carbono
Metano
Óxido nitroso
Dióxido de carbono
Sumidero
Descripción
Sumario:[EN] Constructed wetlands have demonstrated their usefulness in wastewater treatment as key tools in climate change mitigation actions by acting as carbon sinks. However, this capture capacity is offset by greenhouse gas (GHG) emissions generated during the bacterial decontamination processes that occur in the wetland substrate. Therefore, it is crucial to establish a carbon balance that considers the carbon sequestered by the vegetation through phytodegradation and the substrate versus the GHG emitted, which are expressed in terms of CO2 equivalent (CO2e), considering the 100-year global warming potential. In this study, the balance includes direct CH4 and N2O emissions, as well as indirect N2O emissions, calculated using the methodology of the Intergovernmental Panel on Climate Change (IPCC). Non-biogenic CO2 emissions were disregarded, and biogenic CO2 was not considered as a GHG. Two wastewater treatment alternatives were evaluated using horizontal subsurface flow (HAFSsH) and vertical flow (HAFSsV) constructed wetlands as a secondary biological treatment: i) Pretreatment + Imhoff Tank + HAFSsH; and ii) Pretreatment + Imhoff Tank + HAFSsV. Both alternatives include a HAFSsV for primary sludge treatment. The carbon balance was calculated to evaluate the capacity of constructed wetlands both independently and within an integrated wastewater treatment system. The results showed that in both wetland typologies, carbon sequestration exceeds GHG emissions, allowing them to function as carbon sinks. Notably, HAFSsV was more efficient in carbon sequestration per unit area of implantation compared to HAFSsH, considering similar effluent water quality standards. On the other hand, the integrated wastewater treatment system turned out to be a net source of carbon, with the Imhoff tanks being the main responsible for CO2e emissions in both alternatives evaluated. It is recommended to investigate wastewater treatment alternatives that make it possible to dispense with the primary treatment units, so that the integrated system can function as a carbon sink, achieving greater efficiency in both water purification and climate change mitigation.