Predictive Approach of Determining Rate of Degradation of Solid Waste in an Anaerobic Digester

Abstract

This research was carried out to ascertain the rate of degradation of solid waste material in an anaerobic digester. The study also developed mathematical models predict the degradation. A model was developed based on material balance analysis of a digester operation, substrate utilization, production formation and cell growth. The developed model was achieved using Runge Kutta numerical techniques available in the Polymath software. The operations were simulated using a start value of 300 g/dm3 . This value was the concentration of the substrate and the value 1.5 g/dm3 was used as the cell concentration and this was done within 13 days. However, the results obtained from the simulations demonstrated a negative behaviour from 300 g/dm3 to 6.88 g/dm3 y, then the cell growth demonstrated an exponential trend from 1.5 to 39 g/dm3 ). The rate of growth of cell was increased from 0.5 to 2.53 g/dm3 , and death increased from 0.015 to 0.161 g/dm3 . Within these 13 days of simulation, the biogas production, which is the same as the product, follows the same trend from 0 to 219 g/dm3 . Generally, the model was able to predict the results obtained