Effect of Leachate Recirculation on Landfill Methane Production in a Tropical Insular Area

Abstract

Through this study are presented the results of a first test of leachate recirculation on landfill methane production in Guadeloupe archipelago (at the North of the Lesser Antilles, French West Indies, island tropical and humid climate). In French West Indies, methane produced by landfilling is commonly flared without energy recovery. In this paper, assessment is made of the potential for leachate recirculation to increase methane production for energetic purpose in a tropical area. This process could also rapidly reduce the volume of leachate to be treated. The results obtained here show that by injecting 5 m3 of leachate in several draining leachate wells, a sharp increase in the proportion of methane in biogas is observed just a few days after. The older the waste is, the more efficient this process seems to be. In some parts of the waste dome, the methane proportion is nearly doubled at the biogas wellhead. In island context, leachate recirculation could be a long-term solution to produce energy assuming that the quantity of solid waste sent to landfill remains sufficient to maintain a viable operation of the waste dome, to reduce costs of leachate treatment and to create new space for waste storage.