Simple and facile preparation of tunable chitosan tubular nanocomposite microspheres for fast uranium(VI) removal from seawater

The seawater contains 4.5 billion tons of uranium(VI), which is quite enough to provide a continuous supply of infinite nuclear energy. However, it is a sudden need to develop adsorbents from abundant available source, easy collect property, large durability and high uranium(VI) adsorption capacity from seawater. In this work, a single-step process was developed for the preparation of chitosan (Cs) functionalized tubular carbon nanocomposite microspheres (CsFTnCM) for efficient uranium(VI) adsorption from seawater. The application of newly synthesized adsorbent for uranium(VI) removal from seawater is explored. Thus prepared adsorbent (CsFTnCM2) is found to adsorb 99.5% uranium(VI) from seawater. The CsFTnCM2 (Cs/FTn,1:1) comprising NH₂ and COOH content approximately 0.61 mmol/g and 0.23 mmol/g, respectively. This kind of adsorbent possessed a uranium(VI) loading capacity of 0.660 (mg/g) from seawater. The adsorption kinetics not only dependent on the physical structure of the adsorbent but depends on the proportion of FTn in the Cs-matrix. However, the kinetics of uranium(VI) adsorption was increased by increasing the content of FTn up to a certain limit. The adsorption efficiency of uranium(VI) was not affected by the presence of coexisted ions, whose concentration is 1000 times greater than uranium(VI) in seawater. The desorption of uranium(VI) from the seawater exposed adsorbents were investigated and the results showed the uranium(VI) strip from the adsorbents found to be efficiently using Na₂CO₃.