Characterization of organic matter during maturation of Municipal Solid Waste in order to identify chemical parameters indicating stabilization

Disposal of untreated Municipal Solid Waste (MSW)results in long-term methane and leachate emissions, causing adverse ecological effects and giving rise to high costs for landfill aftercare. Therefore, leachate recirculation or mechanical-biological pre-treatments are applied in order to accelerate biotransformation of waste organic matter leading to stabilized residual products. The extent of waste maturation is usually assessed with regard to its level of biological activity by the mean of microbiological tests. However, a deep knowledge of waste organic matter composition is necessary to elucidate processes involved in its biodegradation. Literature on chemical and spectroscopic methods used in the study of OM in all kinds of materials (soils, composts, sediments.)is reviewed as a first stage in the development of a characterization methodology of MSW organic matter. Through careful examination of the evolution of chemical parameters during maturation of waste subjected to leachate recirculation or mechanical-biological pre-treatments, this methodology will first aim at identifying some convenient and reliable chemical indicators of organic matter degree of stability. The relevance of such chemical markers will be evaluated by comparison with biological parameters. As this methodology will allow following up the fate of the main organic compound classes it will enhance the understanding of the influence of the treatment conditions on humification processes and thus will contribute to improvement of waste management.