Selenium (Se) is one of the hazardous trace elements emitted from coal-fired power plants. The Se migration behavior in wet flue gas desulfurization (FGD) slurry is still unclear, and the species of Se in FGD gypsum remains controversial. In this research, the bubbling experiments using simulated slurry with/without gypsum crystallization process were conducted. The experimental results indicated that pure gypsum has poor capability to capture Se components, and only selenite could be trapped in gypsum during its crystal growth stage. Furthermore, the DFT calculation was conducted to provide the microscopic information of Se adsorption and substitution characteristics during gypsum crystallization process. The research findings of this study could help understand the mechanism of Se migration process in FGD slurry, and facilitate the development of effective Se emission control technologies in the future.

硒 (Se) 是燃煤电厂排放的有害微量元素之一。湿法烟气脱硫（FGD）浆液中硒的迁移行为尚不清楚，脱硫石膏中硒的种类仍存在争议。在这项研究中，进行了使用模拟浆料加/不加石膏结晶过程的鼓泡实验。实验结果表明，纯石膏对Se组分的捕获能力较差，在其晶体生长阶段只能捕获亚硒酸盐。此外，进行DFT计算以提供石膏结晶过程中Se吸附和取代特性的微观信息。本研究的研究结果有助于理解 FGD 浆液中硒迁移过程的机理，