https://sj.jst.go.jp/news/202511/n1121-03k.html

A team at Shibaura Institute of Technology and K.F.C. Co., Ltd. have achieved the world’s first successful purification, recovery, and resource recycling of selenium. To achieve this success, the selenate-reducing microorganism Stutzerimonas stutzeri NT-I was used after dissolving rare metals including selenium from waste solar panels.

The research group dissolved CIGS (Cu, In, Ga, Se) from CIGS-type waste solar panels, a type of compound solar cell that contains selenium. After neutralization, the research group combined the dissolved CIGS with the selenate-reducing microorganism NT-I in a reaction environment. NT-I reduces selenate to selenite and selenite to elemental selenium, making it insoluble to be transformed into a solid form. Subsequently, it generates dimethyl diselenide from elemental selenium and synthesizes vaporized selenium. In this experiment, selenium solidification and recovery were performed using a bioreactor and centrifuge. NT-I was added to 3 liters of simulated selenium wastewater and continuously stirred at a stirring speed of 250 rpm and 38℃. Selenium recovery was achieved in 12 hours from an initial concentration of 87.8%. The recovered bio-selenium could be refined to 99.99% purity through simple purification, drying, and chemical reduction.

In the future, the researchers plan to scale up from lab scale to bench scale and ultimately to plant level, aiming to realize a recycling-based society.