Bioinspired Glycolipid-Based Sorbents for Selective Removal and Recovery of Toxic Metals and Rare Earth Elements from Contaminated Waters

Heavy metal and rare earth element (REE) contamination of water is a global environmental challenge that threatens both human welfare and ecosystem health. This dissertation advances the field of sustainable environmental remediation through the rational design and experimental validation of bioinspired materials capable of selectively extracting heavy metals and rare earth elements from complex aqueous environments. Conventional physicochemical technologies, including ion exchange, chemical precipitation, and membrane filtration, provide partial solutions but are often constrained by high operational energy requirements, nonspecific interactions in mixed ion matrices, and secondary waste generation that undermine environmental and economic sustainability. In contrast, nature derived molecules such as glycolipids and amino acid–inspired polymers exhibit intrinsic selectivity and degradability, presenting a promising route toward low impact remediation platforms. This research systematically harnesses these biomolecular features to generate, tune, and evaluate glycolipid-based precipitants, organosilica bound sorbents, and peptide mimetic polymer beads tailored for efficient, reversible, and scalable metal recovery.The initial investigative phase focused on the synthesis and structure activity assessment of glycolipids, amphiphilic molecules comprising hydrophilic sugar headgroups and hydrophobic lipid tails as selective precipitants for Pb²⁺, La³⁺, and Mg²⁺. Galactolipid derivatives consistently exhibited higher precipitation efficiencies (up to 95% metal removal at 5:1 to 10:1 metal:ligand ratios) than their rhamno and xylolipid analogs. Mechanistic analyses revealed that oxygen rich headgroups enhanced metal coordination while the hydrophobic tail promoted phase separation, thereby facilitating filtration and recovery. These findings expanded understanding of glycolipid–metal interactions beyond existing rhamnolipid systems and established a molecular basis for bioinspired precipitation processes. Building upon these insights, the study next explored hybrid organosilica sorbents functionalized with glycolipids (Gal-C14-O) to immobilize and stabilize bioinspired ligands for uranium remediation. The modified surfaces demonstrated robust covalent attachment and maintained metal uptake selectivity across pH 3–6. Kinetic modeling confirmed pseudo second order adsorption behavior consistent with chemisorption, while desorption studies indicated structural resilience under repeated washing. However, column flow through experiments identified limitations in dynamic sorption capacity (0.13 mg U g⁻¹) and non-ideal breakthrough profiles in authentic groundwater, attributed to insufficient ligand surface density and channeling effects. These results underscored the potential of glycolipid-functionalized materials for targeted metal removal while illuminating critical engineering barriers to field deployment. The final phase introduced polymeric beads composed of Poly(Rha-C4-Serine-Acrylamide) designed as a reusable platform for Pb²⁺ sequestration. Guided by hard soft acid base principles, the polymer produced Langmuir type adsorption isotherms and exhibited pronounced selectivity against Mg²⁺ and Cd²⁺. Spectroscopic evidence and desorption studies affirmed the involvement of multi dentate coordination via amide, hydroxyl, and carboxyl functional groups. Operational recycling demonstrated sustained performance across five acid desorption cycles with 62% capacity retention, confirming robust chemical stability with gradual degradation due to surface fouling or partial ligand loss. Collectively, this body of work establishes design principles for bioinspired sorbents integrating molecular recognition, tunable amphiphilicity, and structural stability to achieve selective, efficient, and regenerable metal binding. The materials presented here address diverse aqueous matrices, including mining effluents, saline brines, and contaminated groundwater, offering pathways to replace synthetic chelators and minimize secondary waste. Future directions include expanding glycolipid libraries through reversible addition-fragmentation chain transfer (RAFT) polymerization, optimizing headgroup tail combinations via density functional theory and machine learning, and integrating bioinspired ligands into high surface area matrices such as aerogels, magnetic composites, and metal organic frameworks. Pilot scale validation under realistic flow conditions, combined with life cycle and technoeconomic analysis, will accelerate the translation of these materials into zero waste remediation and resource recovery technologies. Collectively, the findings of this research position bioinspired materials as a transformative, sustainable solution for addressing water contamination and advancing the circular economy.