Effects of phosphoric acid washing on immobilization of heavy metals in municipal solid waste incineration fly ash
垃圾焚烧飞灰磷酸洗涤对重金属的固定效应研究

The influences of phosphoric acid washing municipal solid waste incineration(MSWI) fly ash on the leaching of heavy metals during the washing,the evaporation of heavy metals during the subsequent sintering,and the chemical speciation of heavy metals were discussed.It is showed that in the case of eluting the chloride salts in the fly ash effectively,phosphate pretreatment can reduce the leaching of heavy metals during the washing remarkably,and inhibit the evaporation of heavy metals during the sintering,such that the secondary pollution can be avoided during the disposal of fly ash.At the same time,phosphoric acid washing causes heavy metals in the fly ash to transform into a more stable chemical form both before and after the sintering,and the heavy metals in the sintered products exit in the residual state,such that the long-term environmental security for the resource reuse of the sintered products can be improved.