Sustainable Biopolymers for Environmental Applications: Advances and Future Perspectives Toward a Circular Economy

In recent years, sustainable biopolymers have attracted increasing attention in environmental engineering as alternatives to conventional synthetic materials due to their renewable origins, biodegradability, and functional versatility. However, their performance and technological viability are strongly influenced by structural design, modification strategies, and behavior under realistic environmental conditions. This review critically analyzes recent advances in biopolymers for environmental remediation, covering their main application formats such as hydrogels, membranes, beads, aerogels, and composites, their interaction mechanisms with contaminants, and their performance relative to conventional adsorbents. Particular emphasis is placed on emerging approaches, including advanced functionalization, integration with inorganic phases, and green synthesis technologies, which have significantly improved efficiency, selectivity, and operational stability. Despite these advances, key limitations persist, particularly regarding mechanical robustness, regenerability, reproducibility, and scalability, underscoring the need for standardized evaluation protocols in complex matrices. The role of biopolymers within circular economy frameworks is also examined, emphasizing their capacity to integrate material sustainability, resource recovery, and multifunctional environmental applications. Overall, sustainable biopolymers are positioned not only as substitutes for traditional materials but also as strategic platforms for the development of next-generation regenerative environmental technologies.