Chitin-based renewable materials from marine sponges for uranium adsorption.

Marine sponges of the order Verongida form three-dimensional networks of fibrous chitin, which can easily be extracted. In the hydrated state, these networks are flexible, mechanically stable and can be cut or pressed into any desired form. Here, we show for the first time that chitin-based networks of sponge origin are useful for effective uranium adsorption. They adsorb uranium from solution with a higher adsorption capacity than many other chitinous sorbents. Up to 288 mg/g could be achieved. Solid-state NMR, infrared, and Raman spectroscopy indicated that the uranyl is bound to the chitin by weak interactions. 90% of the uranyl could be desorbed using diluted hydrochloric acid. Uranium adsorption and desorption did not result in any destruction of the chitin-based material.