Efficient Recovery of V, W, and Regeneration of TiO2 Photocatalysts from Waste-SCR Catalysts

Abstract

Discarded Waste-SCR (selective catalytic reduction) catalysts not only harm the natural environment, but also hinder the recovery of valuable metals such as V, W, and Ti, thus resulting in a waste of resources. Therefore, it has become imperative to dispose of Waste-SCR catalysts in large amounts. This study aims to develop a complete, eco-friendly, and economical process of dealing with Waste-SCR catalysts. In this process, the recovery of V and W from Waste-SCR catalysts was achieved in several steps. In addition, the leaching conditions of the acid-base process were optimized, while the structure and composition of the leaching residual were studied in depth. Sodium titanates generated by alkali leaching were then applied for regeneration of the TiO2 photocatalyst. It is worth noting that Fe-doped TiO2 photocatalysts were also prepared, while the required iron source was obtained through acid leaching. Regenerated photocatalyst achieved an excellent performance in the photocatalytic degradation of dye pollutants, which is attributable to small particle size and low forbidden band width. This contributes a new idea to the recycling of solid waste, and the economical treatment of wastewater.