Photo-Assisted Enhancement of Uranium Mine Wastewater Purification by a Self-Assembled Shewanella putrefaciens-CdS Biohybrid System

Integrated light-trapping capability semiconductor and bioreduction advantages of photosensitive biohybrid systems are a promising approach to purify uranium mine wastewater. In this study, we developed a photosensitized Shewanella putrefaciens-CdS biohybrid system for the removal of uranium, which achieved more than 90% U(VI) removal efficiency in real uranium mine wastewater. By use of in situ Kelvin probe force microscopy (KPFM), we identified that photoelectrons generated over CdS were transferred to Shewanella putrefaciens (S. putrefaciens) to enhance the excellent uranium removal performance of the S. putrefaciens–CdS biohybrid. In addition, we performed transcriptomics analysis on the genes (cytochrome c, ABC transport, and electron transfer) linked to U(VI) reduction in the biohybrid system and discovered that these genes were significantly upregulated. This work deepens our understanding of the electron transfer pathways and the physiological activities of the biohybrid system, which provides an important reference for the purification of uranium mine wastewater.