基于固化法共处置飞灰和浓缩液浸出特性研究

在水泥固化时将生活垃圾焚烧飞灰（简称飞灰）以不同的比例代替复合硅酸盐水泥并且用垃圾渗滤液浓缩液代替水进行固化实验，研究了飞灰掺量（40%、50%、60%）、浓缩液替代水对水泥固化法固化效果及重金属（Zn、Pb、Cd、Cr、As、Ba）浸出的影响.结果表明：飞灰掺入量的增加会降低固化体的抗压强度，但浓缩液替代水对固化体的抗压强度没有显著影响.不同重金属的浸出行为受掺灰率的影响不同，掺灰率的增加会减少固化体中Zn的浸出，增加Pb和Cd的浸出，Zn、Pb、Cr、As在第36d可达到稳定浸出量不再增加，Ba的累积浸出量持续增加，加入浓缩液后固化体中Pb、Zn、Cd、Cr、As等重金属的浸出量未超过标准限值，可以满足固化处理对浸出毒性的要求.

Leaching characteristics of fly ash and concentrate treated by solidification method

A cement solidification experiment was conducted by substituting waste incineration fly ash or compound silicate cement and garbage leachate concentrate for water to co-dispose fly ash and leachate concentrate. The solidification effect and the leaching behavior of heavy metals (Zn、Pb、Cd、Cr、As、Ba) were investigated under different fly ash dosages (40%, 50% and 60%). The results showed that the compressive strength of solidified body was decreased with the increasing dosage of fly ash, but there was no significant effects associating with the substitute of leachate concentrate for water. Differential effects of fly ash dosages on the leaching behavior of heavy metals were found in the experiment. The increase of fly ash dosage reduced the leaching of Zn, but increased the leaching of Pb and Cd in the solidified blocks. At the 36th day, the accumulated leaching concentration of Zn, Pb, Cr and As reached a stable status, while the concentration of Ba increased continuously. However, the leaching amount of heavy metals (Pb, Zn, Cd, Cr, and As) in the solidified blocks did not exceed the standard limits set in pollution control standard with the use of leachate concentrate, and thus, the process met the requirement of solidification treatment for leaching toxicity.