Application of Bidentate Chelators in Lead Removal in Wastewater: A Theoretical and Sustainable Approach

Abstract This study presents a theoretical investigation of bidentate chelators for Pb 2 ⁺ removal from aqueous systems using molecular dynamics simulations. Specifically, β-diketone- and dithiooxamide-based ligands, including a nanostructured derivative (LIG2), were evaluated to assess their coordination behavior, stability, and binding affinity toward lead ions. Simulations were conducted for 100 ns to ensure adequate conformational sampling, and key thermodynamic and structural parameters were analyzed, including potential energy, system density, and coordination stability. The results indicate that all ligands exhibit significant interaction with Pb 2 ⁺ ions; however, differences in coordination persistence and structural stability were observed. The dithiooxamide-based systems, particularly the nanostructured ligand, demonstrated enhanced sequestration capacity, attributed to multiple active sites and a favorable coordination geometry. Despite relatively high RMSD values, the complexes remained stable throughout the simulation, with persistent metal–ligand interactions supporting effective chelation. Overall, this work establishes a predictive computational framework for screening chelating agents and highlights dithiooxamide-based ligands as promising candidates for Pb 2 ⁺ removal. These findings provide a rational basis for future experimental validation and the development of efficient materials for wastewater remediation under realistic conditions.