Retention mechanism or REE elementos on Fe nanomineral

Rare Earth Elements (RE) are critical raw materials, essential in modern technologies. The RE concentration in acid mine drainage (AMD) is significantly high, and RE are retained in the solids that precipitated during AMD remediation (i.e., schwertmannite). This study aims to understand how the changes in the solution parameters affect the retention mechanism between RE and schwertmannite. High affinity between RE and schwertmannite has been described, where RE are retained in the solid structure by bidentate binding. However, our recently performed desorption experiments exhibit a potential monodentate binding in light RE, in which a higher desorption reaction was observed. We propose RE EXAFS experiments on RE-enriched schwertmannite before and after desorption experiments. The results will shed light in the effectiveness of remediation treatments in areas contaminated by AMD and the feasibility of extraction of RE from the treatment residuals in passive remediation plants.