Eco-design of Nano-structured Phases for the Removal of New and Emerging Water and Food Pollutants

This thesis explores the development of innovative nanostructured materials for sustainable water remediation within the Safe-and-Sustainable-by-Design (SSbD) framework. Four complementary material systems, TiO₂ granules, clay granules, clay–Fe₃O₄ co-aggregates, and calcium ferrites, were designed, synthesised, and evaluated with the goal of bridging nanoscale functionality with macroscale safety, recoverability, and environmental compatibility. Each system targets a specific remediation challenge, collectively constructing an innovation pathway that progresses from traditional features to multifunctional, magnetically retrievable, and inherently sustainable nanophases. The first set of materials focuses on transforming TiO₂ nanopowders into mechanically robust granules through High-Shear Mechanical Granulation, enabling enhanced handling and reuse without sacrificing photocatalytic efficiency. The second material family introduces granulated natural and synthetic clays, with and without magnetic phases, as low-cost sorbents capable of removing dyes, metals, phenols, and antibiotics while ensuring simple post-treatment separation. The integration of clays with Fe₃O₄ nanoparticles marks the transition to hybrid systems, offering simultaneous adsorption, magnetic recovery, and high stability over multiple cycles. Finally, calcium-based ferrites are proposed as non-toxic and resource-efficient alternatives to conventional ferrites, exhibiting tunable structural, magnetic, and catalytic properties that enable the remediation of diverse pollutants including dyes, metals, phosphates, and antibiotics. Overall, this work demonstrates how strategic material structuring and phase design can enhance performance while reducing environmental risks. The results contribute to advancing next-generation water purification technologies and reinforce the importance of SSbD principles in shaping safer and more sustainable nanomaterial innovation.