Advanced pre-treatment for enhanced anaerobic digestion of waste activated sludge: low thermal combined with solar radiation

• Autor(a) principal: Monteiro, Joana P.
• Data de Publicação: 2024
• Outros Autores: Cruzeiro, C., Duarte, Maria Salomé Lira, Pereira, M. A., Vilar, Vítor J. P.
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/1822/93695
• topic: Thermal hydrolysis; Low thermal pre-treatment; Renewable energy; Photoreactor; Methane production

Anaerobic digestion (AD) is crucial for sewage sludge stabilization and biogas production. However, waste activated sludge (WAS) biodegradability may be constrained by a slow hydrolysis rate. Therefore, the present study aims to analyze the utilization of low-temperature conditions (ranging from 50 to 70 °C) combined with solar radiation to overcome the rate-limiting hydrolysis phase. The increase of temperature improved WAS solubilization (between 6 to 17%) and the highest methane yield of 207±12 L CH4 kg-1 VS achieved at 70 °C with radiation, resulting in 75% higher production compared to the control. Overall, the results demonstrate that the incorporation of radiation into the low-temperature pretreatment substantially enhances the WAS solubilization rate (by 4% when compared to pre-treatment without radiation) and contributes to enhanced methane production (methane yield of around 16% higher than the pre-treatment without radiation).