Phosphation of bottom-ash from MSWI by means of electrokinetics

One of the major drawbacks of using conventional (not enhanced) electrokinetic soil processing to remove heavy metal contaminants involves hydroxide precipitation in the soil fraction near the cathode. The use of an enhancing agent at the cathode compartment, such as acetic acid, to prevent such defects has been largely tested. Previous works have shown good results in the electroremediation of bottom-ash, but even if the electromigration could be enhanced, long periods of treatment limit the real application of this technique. The electrochemical stabilization technique achieves the goal to shorten the time of treatment and to improve remediation of ashes by combining a faster extraction of chlorides, and partially of metals, by electromigration with a stabilization of metals by adding phosphate anions; the latter originate from the electrolysis of H3PO4 at the cathode, and move through the ash by electromigration.