Numerical Study Of County Solid Waste Management At The Dumpsite

Abstract

This study presents the development of one dimensional mathematical model capab le of simulating simultaneous processes of oxygen flow. It is based on some assumptions like the dumpsite is assumed to behave as a bioreactor in which gas phase generation is over i.e. methanogenic is finished and the humic phase is started. This mathemat ical model actually describes the oxygen concentration in the dumpsite. The resulting governing equations in the form of partial differential equation (PDE) have been solved by Finite difference method in which Crank - Nicolson scheme is developed. The goal is to study the three transport parameters; effective diffusivity, decay constant rate and porosity on the oxygen concentration which results in degradation of refuse because after a long term processes in the dumpsite. When all the remaining substrate bec omes more and more resistant to degradation, microbial activity slows down and the humic phase is reached. During the humic phase, the available degradable organic material is either depleted or either the reactions are too slow to consume oxygen entering the dumpsite. The main focus is to study the governing partial differential equations having three transport parameters and their effect on oxygen concentration with velocity of oxygen kept constant. Solutions of the governing equation are obtained using M ATLAB software. The results of the project then are presented in the form of tables and graphs. From the simulated results it is found that for the particular time, oxygen concentration decreases with increase in reaction rate constant ( k ) with times and depths at the dumpsite. Oxygen concentration at the dumpsite increases with increase in porosity (  ) at a particular time at all depths. Oxygen concentration increases with increase in effective diffusivity ( D ) time and depths.