Introduction: The substantial global generation of eggshell waste, estimated at millions of metric tons annually, presents a significant environmental challenge, contributing to landfill burden and associated pollution. This necessitates innovative strategies for waste valorization, transforming this abundant byproduct into high-value biomaterials.
Methods: The valorization process involves initial cleaning and drying of eggshells to remove organic contaminants and moisture. Subsequently, eggshells undergo mechanical processing (crushing, grinding, sieving) to achieve desired particle sizes, and thermal treatments like calcination to convert calcium carbonate into calcium oxide or hydroxyapatite precursors. For real-time process control and quality assurance, advanced non-destructive analytical techniques such as Near-Infrared (NIR) spectroscopy and Hyperspectral Imaging (HSI) are integrated. These optical methods, coupled with machine learning algorithms, enable rapid and accurate assessment of critical parameters including chemical composition, moisture content, and purity, ensuring optimal material characteristics for specific applications.
Results: The application of these controlled processes, rigorously monitored by NIR/HSI and machine learning, yields high-purity eggshell-derived biomaterials. These materials find diverse applications, including advanced bone regeneration scaffolds and dental implants in biomedical engineering, natural exfoliants and skin mineralizers in cosmetics , calcium fortification in food and nutraceuticals, and adsorbents for environmental remediation.
Conclusions: Eggshell valorization represents a compelling example of circular economy principles in action, transforming a low-value waste stream into high-value products. The integration of advanced analytical techniques like NIR spectroscopy and HSI, powered by machine learning, is pivotal for ensuring the quality, consistency, and safety of these biomaterials, thereby facilitating their broader commercialization and contributing to a more sustainable future.
