Comparison of mesophilic and thermophilic anaerobic digestion of food waste: Focusing on methanogenic performance and pathogens removal

Food waste (FW) is a valuable and sustainable resource for anaerobic digestion (AD). However, mesophilic AD, commonly used, poses risks associated with pathogenic microorganisms, potentially limiting the safe utilization of digestion by-products. This study aimed to evaluate and compare methane production efficiencies and pathogen reduction capabilities between mesophilic and thermophilic AD processes. Methane production was assessed in batch and continuous operations under thermophilic conditions, resulting in methane yields of 380 and 360 mL/g VS, representing increases of 5.56 % and 22.44 % respectively compared to mesophilic conditions. Pathogen removal efficiency analysis showed that thermophilic AD achieved Escherichia coli elimination rates between 98.9 % and 99.9 %, with higher removal rates for Salmonella ranging from 77.9 % to 99.8 % compared to mesophilic processing. Overall, results from batch and continuous experiments demonstrate that thermophilic AD not only enhances methane production but also significantly improves pathogens reduction, offering a more effective approach for managing FW in AD systems. The findings of this study enhance the scientific understanding of anaerobic digestion technology in food waste treatment applications and provide crucial technical support and decision-making guidance for environmental management and renewable energy production.