Modelling Temperature Profiles in Food Waste Composting: Monod Kinetics Under Varied Aeration Conditions

Abstract Composting has become a widely adopted alternative to landfilling for food waste management, offering significant environmental benefits by reducing waste and mitigating climate change. This study focuses on enhancing the efficiency of food waste composting by applying mathematical modelling to better understand the underlying biological and physiochemical mechanisms. First-order and Monod-type kinetic were incorporated to predict temperature variations in food waste composting under different aeration conditions. These models were solved and validated against experimental data to assess their predictive accuracy. In the composting process involved intermittent aeration, the modelled temperature profiles showed good agreement with experimental data, with mean temperature differences of 1.99 °C for the first-order and 2.16 °C for the Monod-type kinetic. Monod-type kinetic provided more consistent predictions, achieving a lower relative root mean square error (rRMSE) of 8.03%, while the first-order model exhibited larger temperature fluctuation. Notably, experimental data indicated a second peak in temperature on the seventh day, likely due to delayed microbial activity, a trend not fully captured by either model. In the composting process with continuous aeration, the Monod-type kinetic demonstrated better predictive performance at higher aeration rates, with an rRMSE of 10.82%. However, both models struggled to accurately predict complex temperature fluctuations at lower aeration rates. The results suggest that Monod-type kinetic provides superior prediction accuracy due to its ability to account for the interactions between multiple substrates and microorganisms. This study highlights the value of mathematical modelling in understanding and optimizing food waste composting processes. The findings offer practical insights for improving composting efficiency and operational management, ultimately contributing to reduced environmental impacts from food waste.