Study On Solidification Characteristics Of Heavy Metals For Incineration Of Hazardous Waste

Confronted with more and more serious environment problems alone with the development of economic, many institutes have carried out all kinds of basic research about hazardous waste. As the first choice of dispose of hazardous waste, incineration having the advantages of remarkable volume-reduction, weight-reduction, small floor area and energy recovery has been widely used at home and abroad. The pollution of waste incineration and no-harming of disposing waste have become emphases of people's attention. The heavy metals in municipal solid waste and hazardous waste will be distributed and transformed in the course of incineration without being destroyed. Almost total amount of heavy metal contained in raw waste will be sent out of the furnace. Fly ash and bottom ash produced during incineration contain amount of heavy metals. If fly ash and bottom ash would be directly filled, heavy metals contained in it could leach into the water and pollute environment which will endanger people's health. So doing research on the transfer characters of heavy metals will have far-reaching meanings to no-harming disposing of heavy metals.Stating from the definition of hazardous waste, this paper introduces and analyzes in details such aspects as source and harm of heavy metals during disposing of hazardous waste by incineration, as well as the impact factors. Studying on the solidified and stabilized characteristics of CaO and Ca(OH)₂ to heavy metals using kiln incinerator. The result indicates that the solidified effects of CaO are better than Ca(OH)₂ for Cd,Cr,Ni, while Ca(OH)₂ gets the dominance for Pb and Cu when the temperature is under 600℃.The amounts of Cr,Cd,Ni,Cu in bottom ash have increased as the adding of air coefficient while taking nearly no effect on Pb on studying the effects of air coefficient on transfer of heavy metals. This will provide experimental gist for solidification and stabilization of heavy metals.On base of having read lots of literatures of China and foreign countries, this paper takes the lead in doing groping and basic research on effect of S on transfer characteristics of heavy metals. First of all, using Fact-Sage simulates and counts the effects of Cl,Si,S to transfer of heavy metal. The results show that Cl may accelerate heavy metal transfer from solid phase to gas phase while S and Si present opposite trend because S and Si could form steady salt existing in solid phase. Comparatively, solidification of S on heavy metals excels that of Si.The results of simulates and counts by Fact-Sage will provide theory foundation for the next experiment research. Continue the experiment adopting tube furnace to study the effects of S on the transfer of heavy metals on the base of theory results above.Taking hazardous waste dyestuff-residue and electroplate mud as researching objects, start from equation study by dyestuff-residue incineration and then incinerate the mixture of hazardous waste and S to go on studying the transfer characteristics of heavy metal. The results of experiment reveal that S could accelerate heavy metals transfer from gas phase to solid phase in faith. The extent of transfer relates to the kind of metal,species of metal itself and the quantity of heavy metal in matter. The effect of S on volatile heavy metal Cd is bigger than that on difficult volatile heavy metal Cr,Cu. The research about the effects of S on transfer characteristics of heavy metals will provide data reference and cut new path for no-harming disposing of heavy metals.