Acid-mediated hydrothermal treatment of sewage sludge for nutrient recovery

Hydrothermal carbonization allows material valorization and energy recovery from wet biomass waste. In this study, the hydrothermal treatment of dewatered waste-activated sludge (DWAS) was evaluated at several temperatures (170–230 °C) and reaction times (5–60 min) in an acid-free medium or in media...

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Detalles Bibliográficos
Autores: Sarrión Pérez, Andrés, Rubia Romero, María de los Ángeles de la, Coronella, Charles, Fernández Mohedano, Ángel, Díaz Nieto, Elena
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/703407
Acceso en línea:http://hdl.handle.net/10486/703407
https://dx.doi.org/10.1016/j.scitotenv.2022.156494
Access Level:acceso abierto
Palabra clave:Biofuel
Biomass treatment
Hydrothermal carbonization
Nutrients and energy recovery
Waste-activated sludge
Química
Descripción
Sumario:Hydrothermal carbonization allows material valorization and energy recovery from wet biomass waste. In this study, the hydrothermal treatment of dewatered waste-activated sludge (DWAS) was evaluated at several temperatures (170–230 °C) and reaction times (5–60 min) in an acid-free medium or in media such as citric acid or HCl (0.1–0.5 mol/L). Compared with the DWAS, an increase in the fixed carbon content (>45 wt%) and heating value (18.9–22.9 MJ/kg) was observed in the hydrochar; however, their ash content remained high, which is the main drawback hindering their direct use as a biofuel. The addition of acids during hydrothermal treatment favored the solubilization of N and P in the process water, which required strict control of the reaction time to avoid the recrystallization of P in the hydrochar. Under optimum operating conditions (230 °C, 15 min, 0.5 mol/L HCl), 94 % of P (as of PO4) and almost 100 % of N (14 % as NH4-N) present in the feedstock were concentrated in the process water