Sludge disintegration through advanced rotational hydrodynamic cavitation reactor for improvement of biogas production

Abstract

Sustainable sludge management in wastewater treatment plants (WWTPs) is vital. This study evaluated an advanced rotational hydrodynamic cavitation reactor (ARHCR) for its impact on anaerobic digestion (AD). Sludge was treated under varying rotational speeds, inlet pressures, and pressure drops, followed by biochemical methane potential (BMP) tests to assess AD performance. The results demonstrated the significant biogas yield improvement (14.4 % to 96.5 %) due to effective sludge disintegration, with rotational speed being the most influential factor. Lower-severity conditions may maximize profits by reducing bio-refractory substance formation. A comparative analysis demonstrated the ARHCR's scalability advantage, particularly due to its effective hydrodynamic cavitation generation. Additionally, dimensional analysis confirmed its scale-up potential over similar reactors. An energy balance study revealed a 20 % increase in energy efficiency for AD with the ARHCR, supporting its feasibility as an efficient and sustainable sludge treatment solution. These findings highlight the ARHCR's potential for enhancing WWTP sustainability. © 2025 Elsevier Ltd