Anaerobic digestion (AD) of food waste is strongly influenced by substrate characteristics and operating conditions, particularly substrate composition, particle size, and substrate-to-inoculum (S/I) ratio. In this study, a modified ADM1-R3 model, incorporating a surface-based disintegration kinetics approach, was developed to evaluate the simultaneous influence of these factors on methane production. Sensitivity analysis identified the disintegration and hydrolysis constants as the most influential parameters, while principal component analysis supported a sequential calibration strategy. The model was calibrated using literature data and verified against independent datasets, achieving values of 0.9967 (calibration) and 0.9745–0.9880 (verification). Simulation results showed that optimal performance was observed at low S/I ratios (0.5–1) and intermediate particle sizes (1.4–4 mm), with maximum yields of 419, 744, and 581 for carbohydrate-rich, protein- and lipid-rich, and mixed substrates, respectively. Overall, the model provides a consistent framework for analyzing AD behavior and identifying favorable operational conditions, although further validation under unstable operating conditions is required to fully assess its predictive capability.
Velasco-Pérez et al. (Sat,) studied this question.