Continuous-flow aerobic co-treatment of municipal sludge derived hydrothermal liquefaction aqueous phase with wastewater in treatment plants

Aerobic treatment of hydrothermal liquefaction (HTL) aqueous phase from municipal sludge is a potential on-site treatment option that could help overcome a major challenge, effectively managing HTL aqueous phase. In this study, HTL aqueous phase, derived from mixed sludge cake at 332°C, 16.9¿min, wa...

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Detalhes bibliográficos
Autores: Basar, Ibrahim Alper, Eskicioglu, Cigdem|||0000-0002-7673-134X
Tipo de documento: artigo
Data de publicação:2025
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/439329
Acesso em linha:https://hdl.handle.net/2117/439329
https://dx.doi.org/10.1016/j.jece.2025.117336
Access Level:Acceso aberto
Palavra-chave:Sludge treatment
Aerobic treatment
UV absorbance
Settling
Techno-economic analysis
Àrees temàtiques de la UPC::Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Enginyeria sanitària
Descrição
Resumo:Aerobic treatment of hydrothermal liquefaction (HTL) aqueous phase from municipal sludge is a potential on-site treatment option that could help overcome a major challenge, effectively managing HTL aqueous phase. In this study, HTL aqueous phase, derived from mixed sludge cake at 332°C, 16.9¿min, was blended with synthetic wastewater in a 1:1000 volumetric ratio representative of sludge processing at a full-scale treatment plant. This mixture was then fed into a bench-scale activated sludge unit, comprised of aeration and settling tanks, under organic loading rates of 1.2–1.6¿kg BOD/m3·d. Results revealed that blending HTL aqueous phase into influent wastewater resulted in significant changes in chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), total ammonium nitrogen (TAN), PO43--P, and total phenolics concentrations of influent wastewater. There was no evidence of inhibition on aerobic biomass throughout the testing period. However, significant increases in COD (40–45¿%), TAN (10–14¿%), PO43--P (8¿%), and total phenolics concentrations (75–87¿%) were detected in the treated effluent while the BOD5 of treated effluent was not affected by HTL aqueous phase blending. Although the sludge volume index of biomass significantly increased after blending HTL aqueous phase into the wastewater, the total suspended solids concentration of the settling underflow and sludge recycle were not affected. Finally, recalcitrant compounds were found to increase the UV254 absorbance. The techno-economic analysis showed that returning the HTL aqueous phase to the activated sludge process would increase aeration cost by 22.5¿%, while overall treatment cost would decrease by 13.5¿% through HTL integration.