School of Chemistry and Materials Engineering, Changshu Institute of Technology, 215500, China.
Nuclear Resources Engineering College, University of South China, 421001, China.
J Environ Manage. 2019 Feb 15;232:207-218. doi: 10.1016/j.jenvman.2018.11.051. Epub 2018 Nov 22.
The mass production of municipal solid waste incineration (MSWI) fly ashes has caused severe concerns in regarding to the inherently ecological harm and the decreasing landfilling space. To relieve the heavy metal contamination into the environment and complete a closed-loop electrokinetics (EK), the sequential effects of electrokinetics and alkali activating solidification/stabilization (S/S) technique on the immobilization of HMs in the remnant of MSWI fly ashes were investigated in the research. The compressive strength for the remnant-based solidified product at the proposing time of 18 days was 2.58 MPa, 104.76% higher than that of the MWSI-based specimen with the optimal curing parameters being adopted for the production of the solidified matrices. The leaching concentrations of Zn, Pb, and Cu were 9.74, 0.21, and 0.75 mg/L, correspondingly reduced by 57.84%, 80.19%, and 17.58%, respectively. The opposite correlation between the compressive strength and the leaching concentration was demonstrated for both two groups of the curing samples. The mechanism results showed that the electrokinetics had significantly changed the micromorphology characteristics of MSWI fly ashes and distinctly affected the whole curing process. The cementation and geo-polymerization were comprehensively determined as two of main mechanisms for the immobilization of HMs in the curing matrices.
城市固体废物焚烧（MSWI）飞灰的大规模生产引起了人们对其固有生态危害和填埋空间减少的严重关注。为了减轻重金属对环境的污染并完成闭环电动力学（EK），研究中考察了电动力学和碱激活固化/稳定化（S/S）技术对 MSWI 飞灰残余物中重金属固定化的顺序效应。在提出的 18 天时间内，基于残余物的固化产物的抗压强度为 2.58 MPa，比采用最佳固化参数生产的基于 MWSI 的样本高 104.76%。锌、铅和铜的浸出浓度分别相应降低了 57.84%、80.19%和 17.58%，至 9.74、0.21 和 0.75mg/L。对于两组固化样品，抗压强度和浸出浓度之间均表现出相反的相关性。机理结果表明，电动力学显著改变了 MSWI 飞灰的微观形貌特征，并明显影响了整个固化过程。胶结和地质聚合被综合确定为固化基质中重金属固定化的两个主要机制。
