Technical evolution of landfilling

Landfills are reactors in which liquid, solid and gaseous materials interact giving rise to liquid (leachate) and gas (biogas) emissions together with a solid phase (the landfilled waste) representing a source of potential residual emissions. In order to achieve environmental sustainability in landfilling an important role is played not only by appropriate waste pretreatment but also by in situ treatment measures such as flushing and, when in presence of a residual biological activity, aeration. In situ aeration, applied after Mechanical Biological Pretreatment or after intense anaerobic gas production, has proved to be an important tool in achieving Final Storage Quality, particularly when impervious top covers had been adopted previously