SGA对垃圾焚烧飞灰中重金属的固化性能研究

根据EPA1311、HJ／T299—2007、HJ／T300—2007和HJ557—2009等国内外不同标准，研究了深圳某垃圾焚烧发电厂垃圾焚烧飞灰的浸出毒性，探讨了六硫代胍基甲酸（sixthioguanidineacid，SGA）、二甲基二硫代氨基甲酸盐（sodiumdimethyldithiocarbamate，SDD）和Ca（OH）2浓度对垃圾焚烧飞灰中重金属的固定性能的影响。研究结果表明，随着浸提液pH的降低，该厂焚烧飞灰中大部分金属元素的浸出量增大，焚烧飞灰浸出液中的cd、Ni、Ph和zn浓度分别超过国家危险废物鉴别标准（GB5085．3—2007）规定值的4．75倍、1．47倍、6．72倍和2．20倍，属于危险废弃物，必须进行稳定化处理。当固化剂SGA加入量为0．1mol／kg时，稳定化后的重金属浸出浓度已经低于危险废物鉴别标准，且对Cd、Cr、Cu和Pb的固化性能优于SDD和Ca（OH）2；当固化剂SGA、SDD和Ca（OH）2加入量为0．5mol／kg时，稳定化后的焚烧飞灰重金属浸出浓度均低于国家危险废物鉴别标准（GB5085．3-2007）中的规定值。与SDD和Ca（OH）：相比，SGA对垃圾焚烧飞灰中重金属的固化处理更具有优势。

Research on solidification and stability of heavy metals in municipal solid waste incineration fly ash by using SGA

The leaching toxicity of fly ash from a municipal solid waste incineration （MSWI） plant in Shenzhen was researched according to the different standards of EPA 1311, HJ/T 299-2007, HJ/T 300-2007 and HJ 557-2009. Their stabilization or solidification properties of sixthio guanidine acid （ SGA）, sodium dime- thyl carbamate （SDD） and Ca（OH） 2 for the fly ash were compared. The results indicated that the leaching con- tents of most heavy metals in the fly ash increased with the pH decreasing of leaching liquid, and the leaching contents of Cd, Ni, Pb and Zn exceeded 4.75 times, 1.47 times, 6.72 times and 2.20 times than that of the national hazardous waste identification standard GB5085.3-2007 respectively. From the above research results, the fly ash can be classified to the hazardous waste, and must be stabilized or solidified according to the identifi- cation standard of GB5085.3-2007. The results showed that when the dosages of SGA, SDD and Ca（ OH）2 were 0. 1 mol/kg, 0.5 mol/kg, 0.5 mol/kg, the leaching concentration of heavy metals in the fly ash were less than that of identification standard （ GB5085.3-2007 ） , and SGA had a better stabilization or solidification properties for Cd, Cr, Cu and Pb than SDD and Ca（OH） 2. Compared with SDD and Ca（OH） 2, SGA had an excellent com- prehensive property in treating with the heavy metals in the fly ash from the municipal solid waste incineration.