The Experimental Study On Fly Ash Characteristics And Chemical Stabilization Of Waste Power Plant In Kaifeng City

With the speeding up of urbanization in our country and people's living standard continues to improve,MSW production more and more, burning method with the characteristics of volume reduction, reduction and resource recycling has been vigorously promoted, the resulting hazardous waste- fly ash the proper disposal of concern.The chemical stability method has the characteristics of small capacity, low cost and strong pertinence. It has become the direction of the research and development of fly ash disposal.Due to the various areas of garbage group distinction, in addition in the influence of environmental factors,garbage in different regions incineration power plant characteristics of fly ash, heavy metal group divided into content were different with different waste incineration fly ash, choose the appropriate chemical stabilizer is very necessary.This study focused on the expansion of Kaifeng city waste incineration fly ash, analysis the fly ash composition, particle size distribution, heavy metal content and leaching toxicity and other physicochemical properties; induction of heavy metal content and leaching toxicity characteristic change of fly ash in different size; analysis of the external factors affecting the leaching toxicity; inorganic and organic reagents were used to stabilize the experiment, the screening effect of the reagent was combined with different proportions, adding to fly ash, made the leaching toxicity is up to the standard. The main findings are as follows:?1?Kaifeng municipal solid waste incineration power plant fly ash is light gray powder, strong alkaline,low water content, easy to agglomerate. Fly ash particle size between 0-1000 microns, more than 99.99%of the particles less than 500 microns, the total amount of particles 100 micrometers to 84.42%. Kaifengwaste incineration fly ash components of fly ash and other similar cities, where the highest calcium content,followed by potassium, aluminum, sodium, sulfur and phosphorus.?2?Kaifeng Municipal Solid Waste Incineration high content of heavy metals zinc and lead, a value of4245.02 mg / kg and 1925.8mg / kg; copper, cadmium, chromium, followed respectively 660.42 mg / kg,190.79 mg / kg and 114.16 mg / kg; minimum content of Ni, only 30.98 mg / kg. Compared with other cities, the content of cadmium is higher. The content of heavy metal elements in different fractions fly ash is different, on the whole, copper, cadmium, lead, zinc and more gathered in the large particles of fly ash,chromium, nickel higher levels of small particles in fly ash.?3?In this study, the main use of acetic acid buffer solution method of fly ash leaching toxicity tests to make comparative analysis of the level of oscillation, fly ash leaching of cadmium and lead concentration exceeded. The descending order as leaching rate in acetic acid buffer solution of heavy metals in Kaifeng fly ash : Cd> Cu> Zn> Pb ?Ni> Cr. Fly ash particle size, the pH of the leaching agent, leaching liquid to solid ratio and extraction time change will impact on heavy metal leaching.?4?Kaifeng city waste incineration ash heavy metals in chemical stabilization process, the addition of a chemical reagent alone, NQSZ resin is added 9% or TMT added in an amount of 6%, ash leaching toxicity reaches landfill standards; adding only NaH₂PO₃ and Na₂S can not fly ash leaching toxicity standards. The reagents and heavy metals in different affinity, the stabilizing effect of cadmium on main heavy metal elements in fly ash is NQSZ>TMT>Na₂S>NaH₂PO₄, and the stabilizing effect of the main heavy metal elements in fly ash is TMT>NQSZ>Na H₂PO₄>Na₂S.Composite chemicals can reduce the amount of chemical agents, TMT and Na H₂PO₃ combination H3,H4 added accounts for 5% of fly ash can be achieved landfill standards; TMT and NQSZ resin composition T/N added in an amount of 4%, leaching toxic standard, which uses less than organic-inorganic combination.