垃圾焚烧飞灰螯合稳定化处理效果评价

Evaluation of Chelating Stabilization of Fly Ash from Waste Incineration

对无锡市某电厂垃圾焚烧飞灰,采用硫化钠及二硫代氨基甲酸盐进行螯合稳定化处置,研究螯合前后飞灰中9种重金属(Cu、Pb、Cd、Zn、Ni、Cr、Ba、As、Hg)的浸出毒性变化。结合物相及微观形貌分析,探究飞灰主要组成及污染成分。结果表明,飞灰中Pb、Cd和Ni浓度远超浸出标准。经螯合剂处理后稳定效果明显,其中Cu去除率最高,可达97.55%。而对于Pb、Cd及Ni,螯合后浸出浓度最低值分别为0.01 mg/L、0.01 mg/L、0.04 mg/L。螯合后所有金属浓度均满足安全填埋要求。同时,经螯合稳定后样品的综合潜在生态风险等级也由很强降为很轻,所有金属元素单因子生态危害保持在较低水平,稳定效果明显。

The leaching toxicity of 9 heavy metals(Cu,Pb,Cd,Zn,Ni,Cr,Ba,As and Hg)in fly ash of a power plant incineration in Wuxi city was studied by using sodium sulfide and dithiocarbamate for chelation stabilization.The phase and morphology of composites were analyzed,and the main composition and pollution components of fly ash were investigated.The results showed that the concentrations of Pb,Cd and Ni in fly ash in Wuxi were far higher than the leaching standard.After chelating agent treatment,the stabilization effect was obvious,and Cu removal rate was the highest,which can reach 97.55%.The leaching concentrations of Pb,Cd and Ni after chelation were 0.01 mg/L,0.01 mg/L and 0.04 mg/L,respectively.All metal concentrations after chelation met the requirements of safe landfill.After chelation stabilization,the comprehensive potential ecological risk level of the samples decreased from very strong to very light,and the single factor ecological hazard of all metal elements remained at a low level.The stabilization effect was obvious.