Efficient mercury removal at low temperature in flue gas with metal-organic frameworks modified by iodine

Transition Metal Catalysts for Atmospheric Heavy Metal Removal: A Review of Current Innovations and Advances

Atmospheric heavy metal pollution presents a severe threat to public health and environmental stability. Transition metal catalysts have emerged as a potent solution for the selective capture and removal of these pollutants. This review provides a comprehensive summary of current advancements in the field, emphasizing the efficiency and specificity of nanostructured transition metals, including manganese, iron, cobalt, nickel, copper, and zinc. Looking forward, we delve into the prospective trajectory of catalyst development, underscoring the need for materials with enhanced stability, regenerability, and environmental compatibility. We project that advancements in computational materials science, nanotechnology, and green chemistry will be pivotal in discovering innovative catalysts that are economically and environmentally sustainable. The integration of smart technologies for real-time monitoring and adaptive control is anticipated to revolutionize heavy metal remediation, ensuring efficient and responsive pollution abatement strategies in the face of evolving industrial scenarios and regulatory landscapes.

Interference Effect of Experimental Parameters on the Mercury Removal Mechanism of Biomass Char under an Oxy-Fuel Atmosphere

In this paper, the effect of temperature, adsorption bed height, and initial mercury concentration under oxy-fuel combustion on mercury adsorption by 1% NH₄Cl-modified biomass char was studied. Modification enriched the pore structure of biomass char and increased the number of surface functional groups. Higher temperature would lead to the destruction of van der Waals and reduce the adsorption efficiency, while the change of adsorption bed height had no obvious effect. Adsorption thermodynamics shows that the mercury removal process is a spontaneous exothermic process. The increase of initial mercury concentration would increase the driving force of mercury diffusion to the surface and improve the adsorption capacity. Meanwhile, three kinetic models including the intraparticle diffusion model, pseudo-first-order model, and pseudo-second-order model were applied to explore the internal mechanism of mercury adsorption by biomass char. The results showed that the pseudo-first-order model and pseudo-second-order model could accurately describe the adsorption process, which meant that the progress of external mass transfer played an important role in the adsorption of mercury while chemical adsorption should not be ignored. The intraparticle diffusion model indicated that internal diffusion was not the only step to control the entire adsorption process and did not have an inhibition on mercury removal. Higher initial mercury concentration would promote the external mass transfer progress and chemical adsorption progress. In addition, higher temperature inhibited the external mass transfer, which was not conducive to the adsorption of mercury.