The Verification of the Mathematical Model and the Optimization of the Municipal Solid Waste Composting Process

The aims of this work were to develop a mathematical model for composting municipal solid waste (MSW), to verify the proposed model with independent experimental data and to determine the optimum values for the initial moisture content and airflow. Separated MSW (with the addition of poultry manure, mature compost and sawdust) was used as materials for laboratory simulation. The experiment was conducted in three laboratory reactors (35 L) with forced aeration. Experimental data from one reactor were used to estimate five kinetic parameters in the proposed model and the verification of the model was performed using experimental data from the two reactors. Kinetics is based on the decomposition rate of organic matter. The estimation of kinetic parameters was done using data for four measured dynamic variables (organic matter conversion, O2 and CO2 concentration, and substrate temperature). Mathematical model was implemented in MATLAB. The proposed kinetic model is:   20) (T 0.002 (2.8001 1.0176 0152 . 0    T k with the reaction order 1.6. Comparisons of experimental and simulation results showed good agreement, especially in the mesophilic-thermophilic phase of the process, considering a high heterogeneous system. Optimum values for the initial moisture content in the material (45%) and airflow (0.50 mhkgOT) were estimated using numerical simulations for different initial conditions.