Effects of Intermixed Soils and Decomposition on Hydraulic Conductivity of Municipal Solid Waste in Bioreactor Landfills: Fid-Bau Portal

Effects of Intermixed Soils and Decomposition on Hydraulic Conductivity of Municipal Solid Waste in Bioreactor Landfills

Hossain, Md. Sahadat / Haque, Mohamed A.

Abstract

To estimate the generated leachate and design of a leachate recirculation system, a clear understanding of the hydraulic conductivity of municipal solid waste with degradation, and the effects of intermixed cover soils, is necessary. Two sets of laboratory-scale bioreactor landfills were simulated and sampled at various phases of decomposition. The state of decomposition was quantified by methane yield, pH, and volatile organic content. The matrix structure of the degradable solid waste component was broken down because of decomposition. However, daily cover soil, a nondegradable constituent of municipal solid waste, remained constant. Therefore, interaction between daily cover soil and municipal solid waste particles are expected to affect hydraulic characteristics resulting from degradation. The current study shows that the hydraulic conductivity of municipal solid waste with cover soil is lower than that without any intermixed cover soils. Based on experimental results, hydraulic conductivity of municipal solid waste samples in (aerobic) phase I is $5.8 \times 10^{- 3} cm / s$ , and drops to $2.6 \times 10^{- 3}$ and $1.7 \times 10^{- 3} cm / s$ , with 20 and 30% cover soils, respectively. Hydraulic conductivity decreases with increasing soil percentage. Therefore, the effects of cover soils on municipal solid waste hydraulic conductivity should be evaluated and taken into consideration during the design and operation of a landfill recirculation system.