Tunable dye adsorbing materials from crab and shrimp waste shells for water remediation

Crab and shrimp shells are waste byproducts from shellfish farming and processing. In this study, we demonstrated that it is possible to obtain individual shell components either separately or in combinations. These diverse materials were composed of calcium carbonate and organic molecules inter- and intra-mineral, calcium carbonate and organic molecules intra-mineral, organic molecules such as chitin and proteins, only calcium carbonate, and only chitin. These substrates were tested for the adsorption of Methylene Blue and Eosin dyes. The goal is to demonstrate that the organic dye adsorption capacity can be modified by controlling the degree of deconstruction of the starting material. The best adsorption for the positively charged Methylene Blue was achieved on the chitin-calcium carbonate substrates, while the negatively charged Eosin adsorbed best on the chitin substrate. In conclusion, this research demonstrates that it is possible to obtain different materials by deconstructing the shells from crabs and shrimps at various levels reducing the generation of additional wastes. Moreover, these materials exhibit features that are related to the original material and possess new properties that can be also exploited in other fields like material sciences.