School of Civil Engineering, Changsha University of Science and Technology, Changsha, 410114, China; CONACYT Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mich, 58030, Mexico.
School of Zijin Mining, Fuzhou University, Fuzhou, Fujian, 350108, China; CONACYT Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mich, 58030, Mexico.
Chemosphere. 2021 Nov;283:131240. doi: 10.1016/j.chemosphere.2021.131240. Epub 2021 Jun 18.
Hazardous heavy metals in Municipal Solid Waste Incineration (MSWI) fly ash are a threat to the environment and ecosystems. The objective of the work is to investigate the solidification of MSWI fly ash and the immobilization of the heavy metals through alkaline activation reaction with waste glass as an additive. Compressive strength measurement, X-ray diffraction (XRD), Si nuclear magnetic resonance spectroscopy (Si NMR) and scanning electron microscope (SEM) were performed to evaluate the solidification effect and characterize the microstructure of alkali-activated MSWI fly ash-based mortars. The leaching test, back-scattered electron microscopy (BSE) and X-ray photoelectron spectroscopy (XPS) were conducted to determine the heavy metals' immobilization effect and their immobilization forms. It was found that waste glass addition effectively reinforced the solidification of MSWI fly ash and immobilized the heavy metals. With 40% addition of waste glass, the compressive strength reached a maximum of 3.55 MPa. The immobilization efficiency of Cr increased with the addition of waste glass, while that of Cu, Pb, Zn and Cd is dependent on the eluant final pH, which decreased with the decrease of eluant final pH. The main immobilization forms include physical encapsulation, the formation of alkaline environment and the generation of silicate compounds.
城市生活垃圾焚烧飞灰中的有害重金属对环境和生态系统构成威胁。本工作旨在研究通过碱性激活反应用废玻璃作为添加剂固化 MSWI 飞灰并固定重金属。抗压强度测量、X 射线衍射 (XRD)、硅核磁共振波谱 (Si NMR) 和扫描电子显微镜 (SEM) 用于评估碱激活 MSWI 飞灰基砂浆的固化效果和表征其微观结构。浸出试验、背散射电子显微镜 (BSE) 和 X 射线光电子能谱 (XPS) 用于确定重金属的固定效果及其固定形式。结果表明，废玻璃的添加有效地增强了 MSWI 飞灰的固化并固定了重金属。当废玻璃添加量为 40%时，抗压强度达到最大值 3.55 MPa。随着废玻璃的添加，Cr 的固定效率增加，而 Cu、Pb、Zn 和 Cd 的固定效率则取决于洗脱液的最终 pH 值，随着洗脱液最终 pH 值的降低而降低。主要的固定形式包括物理封装、碱性环境的形成和硅酸盐化合物的生成。
