Predicting Bioreactor Landfill Air Space by Estimating Geotechnical Properties of Waste

Abstract

Intensive research has focused on the settlement of the typical Municipal Solid Waste (MSW) in bioreactor landfills, but relatively little attention has been given to the settlement of individual refuse components. The objective of this paper is to estimate and compare the compressibility parameters of different waste fractions, such as: textile, paper, and mixed waste through measuring the change in the physical properties, and settlement characteristics of waste in six lab-scale bioreactor landfills operated under anaerobic conditions. Primary compression index (Cc), and coefficient of volume compressibility (mv) were estimated for all three waste materials using time-settlement data. The primary compression index (Cc) increased from 0.31 for textile waste to 0.45 for paper waste, and 0.63 for mixed waste. It can be noted that Cc increased with increasing the waste organic content. The value of the coefficient of volume compression (mv) suggests that the biodegradation increased the values of mv of all types of waste samples. Textile waste incorporated the lowest value of mv compared to all other solid waste fractions. This may be attributed to the fact that the textile is slowly biodegradable compared to paper and food wastes as stated earlier. Textile waste cells had the least value for all compressibility parameters. Proper estimation of the waste compressibility parameters would allow engineers and landfill designers formulate mathematical models to better estimate available air space saving and expected time dependent deformation patterns at field scale bioreactor landfill cells, which subsequently increases life time of bioreactor landfills.