(Poster session) Processing & Material

[P034B] Selective Adsorption of Critical Heavy Metals Using Functionalized Layered Double Hydroxide

○Maryyam Saddiqua^{1[Student presentation: Master’s course]}, hideyuki takahashi¹, shun yokoyama¹, koji yokoyama¹, Tomohito kameda¹ (1. Tohoku university)

Keywords:Critical metals, Adsorption, chelating agent

The increasing demand of critical heavy metals to be employed in clean energy technologies and lithium ion batteries of electrical vehicles is posing threats to environmental sustainability and global supply chain due to un even distribution and ethical concerns about mining of critical minerals. These issues require the efficient strategies to recover and separate these metals from waste to be reused again. However, selective separation of some metals in the same system/solution is very difficult due to their similar physicochemical properties.Our research explores the use of organic intercalated layered double hydroxide (LDH) material as an adsorbent for the selective recovery of critical heavy metals from aqueous solution via metal-ligand complexation. This method leverages the differences in formation constants and precipitation behavior to enable targeted separation. The calculation results show that the difference in the formation constant of the heavy metal complexes with the organic ligand, coupled with variations in the behavior of the precipitated species will facilitate selective separation of these metals.LDH intercalated with organic chelate forming ligand was synthesized by using co-precipitation method and characterized by using various techniques including XRD to confirm the LDH layered structure, TG-DSC to see the trend of weight loss of the organic content present in the material, and stability test to evaluate the stability of the material at lower pH conditions. The synthesized material has a typical hydrotalcite like layered structure , having a significant wt% of the organic content and is stable at low pH conditions. The material was them employed as an adsorbent to test its selective adsorption ability. Other results about the adsorption experiments will be presented in presentation.