Long-term assessment of anaerobic co-digestion of food waste and microalgae: process stabilization, methane yield and agronomic properties of digestate

This study aimed at assessing the anaerobic co-digestion of food waste and microalgal biomass. Microalgae were harvested from an open treatment pond used for digestate treatment. For that, two continuous laboratory-scale reactors were operated over 200 days at ambient temperature. Results obtained s...

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Detalles Bibliográficos
Autores: Pereira de Castro, Iacy Maria, de Alencar Neves, Thiago, Pereira Rosa, André, França da Cunha, Fernando, Passos, Fabiana Lopes del Rei|||0000-0001-7501-988X
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/438904
Acceso en línea:https://hdl.handle.net/2117/438904
https://dx.doi.org/10.1016/j.algal.2025.103947
Access Level:acceso abierto
Palabra clave:Anaerobic digestion
Biofertilizer
Biogas
Microalgal biomass
Resource recovery
VFA
Àrees temàtiques de la UPC::Enginyeria civil::Impacte ambiental
Descripción
Sumario:This study aimed at assessing the anaerobic co-digestion of food waste and microalgal biomass. Microalgae were harvested from an open treatment pond used for digestate treatment. For that, two continuous laboratory-scale reactors were operated over 200 days at ambient temperature. Results obtained showed that the reactor fed with a 75:25 mixture of food waste and microalgae (based on volatile solids) improved process stability, overcoming volatile fatty acid accumulation and pH drop, compared to mono-digestion of food waste. Consequently, co-digestion increased methane yield in 20–32 % (0.22 L CH4/g VS). Moreover, the agronomic assessment revealed that digestates exhibited potential for use as a biofertilizer, i.e. adequate organic matter and nutrient contents heavy metals concentrations below limits established by different regulations (i.e., Zn, Ni, Cr, and Cu). These findings indicate that the anaerobic co-digestion of food waste and microalgae may offer potential for biomass valorisation in a circular approach, generating bioenergy and biofertilizer.