An accelerated, on-site bottom ash stabilization treatment and the effect of long-term leaching of bottom ash

Ash stabilization plays an important role in the safety and security of landfills and in driving ash recycling. An on-site technology that uses an optimized detachable container and stabilizes ash with sprinkling water and... [ view full abstract ]

Ash stabilization plays an important role in the safety and security of landfills and in driving ash recycling. An on-site technology that uses an optimized detachable container and stabilizes ash with sprinkling water and aeration using CO₂ was developed. Experimental verification of this technology was undertaken (treatment condition: L/S=0.6-0.7, 24h duration). Two treatment methods were investigated using unsieved samples of municipal bottom ash (2.2t): 1) sprinkling water only 2) sprinkling water combined with aeration using CO₂.

The chloride content of treated bottom ash decreased by up to 72%. The bottom ash treated by aeration with CO₂ showed reduction in solubility of Pb by up to 90%, with carbonation causing an exothermic reaction. In the lysimeter test (column size : φ104 × 400 mmH) conducted to evaluate the long-term dissolution performance, leachate data was acquired over 400 days from both treated and untreated bottom ash. Results showed that the incineration bottom ash treated with sprinkling and aeration using CO₂ showed lower pH, EC, cumulative Cl and Pb after 400 days than that of untreated incineration ashes.