BIORRELLENOS: PERSPECTIVAS TRAS DOS DÉCADAS DE EXPERIENCIAS EN EL MUNDO

Abstract

Concepts like ‘bioreactor landfill’ or ‘sustainable landfill’ have been resonating in specialized technical and scientific meetings for a long time. However, there are still many myths surrounding this technique which, in some places, mainly the United States, has been practiced for over twenty years. This paper summarizes the current state of knowledge on bioreactor landfills. It begins with a review of the history of this technique, proposed in the 70s for the first time. The objective of bioreactor practices is to accelerate the degradation of municipal waste (MW) to avoid environmental liabilities. Advantages and disadvantages of these particular landfills are discussed. Having identified the MW moisture content as the principal parameter to control, different types of bioreactors have been developed, according to the aeration modes: anaerobic, semiaerobic, aerobic and hybrid bioreactors. As a guide for new projects arising and required in Iberoamerica, general guidelines for design and operation of new anaerobic and semiaerobic installations are gathered, including the leachate reinfiltration and liquid and gas collection systems, the main operational implications, and the monitoring needs. Four practical cases are described as examples: a full scale experience which has become an international reference, a model of semiaerobic landfill suited to middle-income and developing countries, and two cases representing the progress of these methods in Iberoamerica. Finally, the prospects of advance for this practice through research and with regard to its extension in this region of the world are presented.