ABSTRACT Biowaste composting relies on microbial degradation under controlled aeration, temperature, and moisture conditions to transform organic waste into usable compost, whereas municipal solid waste is often improperly managed in developing countries This study focuses on biowaste composting in a continuous-flow reactor operated with upward forced aeration in a closed system, using a mathematical model to simulate the spatio-temporal behavior of temperature, moisture, and biodegradable volatile solids across multiple slots and layers. For conducting this study, the reactors consist of seven sequential slots, each containing six vertical layers, through which a waste sample passes to the next slot every three days, to achieve a total composting time of 21 days. A systematic aeration strategy (Air Flow: Qi → Qi/2 → Qi) was incorporated to simulate realistic operational conditions for thermophilic. The Simulation results reveal that the maximum temperature is reached in the Upper Layer (UL) due to concentrated oxygen (around 65 °C), and the Lower Layer (LL) contains a temperature of around 32-38 °C, which is conducive to less microbial growth. Volatile solids reduction of each bio-waste sample was around LL:30-UL:58%, whereas moisture content progressively reduced to 45-48% by Day 21. Oxygen consumption patterns also mirrored biological activity, with minimum concentrations (~16-17%) occurring during the thermophilic peak in Slot 4 out of 7 slots. And the total waste decomposed in the middle layer (L3) was around 52% of the total bio-waste. The model performed well, with relatively high R² values (0.61–0.77) between simulated and actual temperatures. Overall, the proposed continuous-flow model demonstrates effective biowaste composting performance with potential heat generation, indicating its applicability for sustainable composting systems. Also, this model can assist in developing different biowaste treatment facilities in developing countries, contributing to long-term development goals.
Amin et al. (Sun,) studied this question.