Six Years Temperature Monitoring Using Fibre-Optic Sensors in a Bioreactor Landfill

Abstract

Temperature is a relevant physical parameter to monitor the biodegradation phases of waste mass. Irstea and the landfill operator SAS Les Champs Jouault have been collaborating since 2011 to study the temporal evolution and the spatial distribution of temperature in a municipal solid waste cell. Using distributed temperature sensing technology, optical fibres were installed in waste mass composed of household waste and industrial waste at different depths during the landfilling period. Temperature distributions were studied from 2012 until 2018 and the same evolutions are observed everywhere with more or less important amplitude variations depending on the location of the measurement point. When landfilled, the waste is at ambient temperature and a significant increase is observed the following year due to the exothermic impact of the aerobic biodegradation phase before a slower decrease during the anaerobic biodegradation phase over several years. Thermal parameters of the waste mass and the surrounding soil, as well as the heat generation function, are calculated using numerical simulation to reproduce the temperature evolution and its spatial distribution. The study of the long-term temperature evolution makes it possible to evaluate the favourable period during which the deposit cell will be in optimal conditions to promote the biodegradation waste processes.