In the Netherlands 2.5 million tons of waste is landfilled yearly. Current practice shields the environment from emitted landfill pollutants, yet the applied techniques require indefinite renewal of protection barriers, which is costly and unsustainable. Novel techniques strive to alter waste properties such that the emission potential of landfill waste is reduced to an environmentally safe level. These novel techniques, i.e. aeration of the landfill waste and recirculation of leachate, both aim to increase natural decomposition of the organic waste fraction. We know from soil organic matter that increased decomposition alters its characteristics such that dissolved organic matter fractions are reduced and that the remaining solid organic matter has an increased capacity to bind contaminants. Currently, we expect similar behaviour in landfill solid waste. Yet, research regarding the effect of aeration and leachate recirculation on the characteristics of solid organic matter in landfill waste has so far received very little attention. We will investigate these effects , particularly with regard to the stability and contaminant binding properties of organic matter, by simulating aeration and leachate recirculation in specially designed landfill simulation reactors (LSRs). The PhD research is part of the NWO-CURE project in which we work closely together with TU Delft.