Moisture Distribution in Bioreactor Landfills: A Review: Fid-Bau Portal

Moisture Distribution in Bioreactor Landfills: A Review

Kulkarni, Hanumanth S. / Reddy, Krishna R.

Abstract Municipal solid waste (MSW) generation has been increasing every year in the United States and other parts of the world, as recent studies document. Therefore, landfill design, operations and treatment play an important role in managing MSW. Bioreactor landfills were recently introduced as a mechanism by which to overcome the issue of prolonged waste biodegradation in the conventional landfill. In a bioreactor landfill, the leachate that is generated is collected from the leachate collection removal system and then recirculated into the landfill to increase the moisture content of MSW. That increased moisture content then helps to distribute the microbes and nutrients required for suitable MSW biodegradation. However, the body of knowledge on the effective operation of bioreactor landfill is limited. Few studies have documented the performance of bioreactor landfill in the context of moisture distribution in the MSW. Both improper leachate recirculation and an empirical approach to the design of leachate recirculation systems (LRS) have led to a large variation in the performance of these systems. A detailed literature review on moisture distribution in bioreactor landfills is reported in this paper. The studies reported in the literature review are divided into laboratory studies, field studies, combined laboratory and field studies, and mathematical models. Based on the literature review, it is evident that the LRS design is based on either exceptionally limited information from laboratory and field observations or the insufficient or improper selection of MSW properties. Further, the assumption of that MSW is homogeneous isotropic and ignoring the effect of unsaturated hydraulic properties and effect of temperature can lead to large variation in the actual performance of bioreactor landfill.