Organic Complex Chelators for Stabilization of Heavy Metals in Fly Ash

The organic complex chelators(OCC) were synthesized and applied to stabilization of heavy metals in fly ash according to the municipal solid waste landfill pollution control standard. The influences of different chelators, amount of chelator, pH value of leaching, solidification time were investigated and optimized. Comparing to the traditional inorganic chelator, this OCC has more powerful performance of stabilization. Under the optimized conditions, the leaching concentrations for typical heavy metals Pb and Cd were less than 0.19 and 0.11 mg/L, respectively, which could meet the demand of landfill. The organic complex chelators could react with heavy metals to form stable complexes, which would be embedded in fly ash particles and have the strong ability to prohibit leaching from acidic environment.