A method for detoxifying industrial wastes is presented, aiming at a safer management and reuse. Focusing, in particular, on bottom ashes from a Municipal Solid Waste Incinerator (MSWT), the proposed treatment allows to extract soluble salts (e.g. chlorides), "washing" the ash by means of an electric field, instead of water, and using the same electric potential to move ions and let stabilizers (e.g. phosphate anions) to react with metal ions. The paper presents the results of six experiments, which were carried out varying the voltage between the electrodes (2-2.4 V/cm) the amount of phosphoric acid (0.9-1.5% - weight of acid/weight of ash) and fixing the time of treatment (24 hours). A significant leaching reduction was observed after each electrochemical test, namely 92% for Pb, 97% for Ba, 90% for Cu and 80% for chlorides; the latter are oxidized at the anode, and definitively leave the ash in the form of gaseous chlorine.
Electrokinetic stabilization as means of dealing with waste materials polluted by both salts and heavy metals
FERRO, Sergio;MARTINEZ, Carlos Alberto;DE BATTISTI, Achille
2008
Abstract
A method for detoxifying industrial wastes is presented, aiming at a safer management and reuse. Focusing, in particular, on bottom ashes from a Municipal Solid Waste Incinerator (MSWT), the proposed treatment allows to extract soluble salts (e.g. chlorides), "washing" the ash by means of an electric field, instead of water, and using the same electric potential to move ions and let stabilizers (e.g. phosphate anions) to react with metal ions. The paper presents the results of six experiments, which were carried out varying the voltage between the electrodes (2-2.4 V/cm) the amount of phosphoric acid (0.9-1.5% - weight of acid/weight of ash) and fixing the time of treatment (24 hours). A significant leaching reduction was observed after each electrochemical test, namely 92% for Pb, 97% for Ba, 90% for Cu and 80% for chlorides; the latter are oxidized at the anode, and definitively leave the ash in the form of gaseous chlorine.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
