COMPARISON OF A BIOREACTOR AND TRADITIONAL SUBTITLE 'D' LANDFILL ― A SOUTH TEXAS CASE STUDY

摘要

A bioreactor landfill is designed and operated to quickly transform and stabilize any readily/moderately decomposable organic waste by controlling and enhancing microbiological degradation processes. This type of landfill allows a more active landfill management that represents a better understanding of biological, chemical and physical processes involved. In contrast to the conventional permanent storage approach to preserve the waste, it focuses on enhancing degradation processes to stabilize the waste, thus minimizing potential long-term environmental impacts that may follow a containment system failure. This paper presents HELP model computer simulations of a theoretical South Texas landfill, modeled as a bioreactor landfill and a traditional dry cell landfill. Waste degradation, methane gas production and overall landfill performance are discussed. Design concepts and methods of reintroducing leachate into the landfill are presented as well. The HELP model analysis showed that a bioreactor landfill constructed in south Texas could produce as much as 844 inches of leachate per year after closure, with average annual generation rates of 391 inches after closure, and 110 inches during active filling. A system of horizontal trenches and vertical recharge wells can be constructed to handle this volume of leachate. Implementing bioreactor technology has potential for economic and environmental gain without compromising public health and safety.