Pathways for Sustainable Adoption of Chitosan-Based Beads in Water Treatment

The increasing environmental concerns associated with petroleum-based ion exchange resins have spurred interest in sustainable alternatives, such as biopolymeric beads derived from chitosan. This study evaluated the sustainability of three porous chitosan particles synthesized with low-toxicity solvents (methylpentane porous chitosan particles, azocarboxamide porous chitosan particles, and tween porous chitosan particles) using techno-economic analysis and life cycle assessment. The results, normalized to both mass of particles produced and percent removal of methylene blue, revealed that azocarboxamide porous chitosan particles were the most cost-effective variant, despite the methylpentane ones exhibiting the highest removal efficiency. Environmental impacts were consistent across most categories, with azocarboxamide porous chitosan particles showing higher impacts for human toxicity (carcinogenic) and ozone depletion potential. Sensitivity analysis identified precursor costs, synthesis yield, chitosan and NaOH amounts, and electrical energy consumption as key drivers of sustainability. The findings emphasize the importance of considering both synthesis yield and treatment efficacy when evaluating the sustainability of chitosan-based ion exchange resins. Process optimization and exploration of eco-friendly alternatives are recommended to enhance the sustainability of these materials. This study contributes to the development of sustainable water treatment methods and promotes the transition towards a circular economy in the ion exchange resin industry.