Potential of horseshoe crab shell waste as adsorbent for wastewater treatment: mini review

Abstract The rising complexity of wastewater due to industrial and municipal activities poses significant environmental challenges, particularly in Malaysia. This mini review explores the potential of horseshoe crab shell waste as an effective and sustainable adsorbent for wastewater treatment. Horseshoe crab shells, which contain high levels of chitin, can be processed into chitosan, a biopolymer with strong adsorption properties for various pollutants, including heavy metals, organic compounds, and dyes. Using horseshoe crab, shell-derived materials offer a green alternative to synthetic adsorbents, promoting circular economy principles by valorizing waste. This review examines different preparation techniques, including silver nanoparticle functionalization, deacetylation, and pyrolysis, each of which optimizes the material’s adsorption capacity for specific pollutants. Key benefits of these bio-based adsorbents include their biodegradability, cost-effectiveness, and the potential to reduce reliance on synthetic materials. The review also addresses challenges such as production scalability, resource sustainability, and material consistency, highlighting future directions for enhancing the applicability of horseshoe crab shell-based adsorbents in diverse wastewater treatment scenarios.