Catalysing Sustainability with Keratin-Derived Adsorbent Materials for Enhanced Heavy Metal Remediation

Heavy metal contamination has been a significant issue globally often interconnected with broader environmental and social factors. Biosorption, emerged as a potential solution to sequester heavy metal ions using range of ceramics and polymers lean towards natural polymers for sustainability. Among these natural polymers, keratin-based adsorbents have attained attention due to its structural features. Though numerous review articles have reported the use of keratin for adsorption of toxic pollutants and methods to develop materials with desirable physical, chemical, thermal and mechanical properties, the present review particularly discuss the structural–functional relation to explore the modification and tenability to improve its adsorption efficiency for heavy metals. Their interactions with functional groups present on keratin molecule and further, different extrinsic aspects such as extraction methods’ impact on removal efficiency of keratin and underlying mechanisms elucidated through various adsorption model employed by researchers is also discussed. This review also reports studies on improving the inherent heavy metal adsorption capacity of keratin by compositing with other polymers. Additionally, the functionalization of keratin molecule has been explored for not only improving the adsorption capacity but also the morphological characteristics of the materials developed. Overall, the article highlights the advancements in keratin-based materials as effective adsorbents for heavy metal removal from wastewater and the need for further research to optimize their properties and performance.