Microwave Enhanced Solidification of Gaseous Mercury from Flue Gas by a Novel Selenium Functional FeCo-LDH Based Halloysite Adsorbent
The immobilization of Hg0 and detoxication of Hg-containing composites are enormous challenges for Hg pollution control, which provide a high requirement for the design and synthesis of materials. Herein, a new composite with halloysite, selenium, and transition metals as raw materials (FeCo-LDH/HNTs@Se) for a Hg0 trap was designed by precipitation with ion exchange and an in situ selenization method. Intrinsic features such as high affinity, microwave permittivity (109–1012), large surface area, abundant pores, and many active components favored Hg0 removal and immobilization. The removal performance, flue gas tolerance, and synergistic effect of active components were improved greatly when microwave was added. The study indicated that (1) the Hg0 removal efficiency of the composite could reach 99.4%; (2) the composite had excellent tolerance to different industries’ flue gases. The electron exchange of Co(II)/Co(III) and Fe(II)/Fe(III) and the existence of Se and SeO2 were important for Hg0 immobilization. HgSe was the main adsorption product based on both X-ray photoelectron spectroscopy (XPS) and an online lab-built thermal decomposition system (TPD-AFS) analysis, which made the used-materials possess low mercury leaching content (0.09 mg·L–1) lower than the US EPA regulatory value (0.2 mg·L–1). This work provides a sound way for mercury control, which is significant for environmental protection.
危险品化学品经营许可证（带存储）