Application of different stabilization treatments for municipal waste combustion APC

In this study, different treatments methods on air pollution control (APC) ash from municipal solid waste combustion were applied, aimed at achieving the immobilization of critical contaminants such as heavy metals as well as the removal of soluble salts. An accelerated carbonation treatment, a chemical stabilization treatment based on the addition of sorbent BauxolTM and a washing treatment, either separately or in combination, were carried out. The treatments applied separately were not fully effective, since the stabilization treatments were able to reduce the leaching metals but no effect was observed on chloride. Conversely, washing allowed for the removal of chloride, but heavy metals were leached out in the wastewater. The optimal treatments combination assessed during this study resulted to be the chemical stabilization with BauxolTM combined with water washing, since the resulting residue became a non hazardous waste according to the EU legislation and the process water was characterized by a relatively low content of metals, with obvious advantages in terms its treatment.