Hydroxyapatite derived from eggshell embedded on functionalized g-C3N4 for synergistic extraction of U(VI) from aqueous solution

• Published in: Chemosphere (Oxford) 2024-09, Vol.364, p.143018, Article 143018
• Main Authors: Dhanasekaran, A., Priyadarshini, N., Perumal, Ilaiyaraja, Suresh, G., Sagadevan, Suresh
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon nitride; Diglycolamic acid; Hydroxyapatite; Nanocomposite; Uranium
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.143018

In this paper, we report hydroxyapatite derived from egg-shell biowaste embedded on diglycolamic acid functionalized graphitic carbon nitride nanocomposite (abbreviated as HAp@D-gCN). The compositional and morphological characteristics of HAp@D-gCN were evaluated using scanning electron microscope, X-ray diffraction, BET, FTIR techniques and surface charge using zeta potential measurement. The sorption of U(VI) species on HAp@D-gCN was investigated through batch studies as a function of pH, contact time, initial U(VI) concentration, adsorbent dosage and ionic strength. The adsorption of U(VI) onto HAp@D-gCN was confirmed by FTIR, XRD and EDS elemental mapping. Adsorption kinetics follow pseudo second order model and it attains equilibrium within 20 min. Adsorption isotherm data correlates well with Langmuir isotherm model with a maximum sorption capacity of 993.6 mg of U(VI) per gram of HAp@D-gCN at 298K. U(VI) can be leached from the loaded adsorbent using 0.01 M Na2CO3 as desorbing agent and its sorption capacity remains unaffected even after 4 adsorption-desorption cycles. Hence, the present study reveals that HAp@D-gCN nanocomposite could serve as an environmental friendly material with potential application in environmental remediation. [Display omitted] •Biowaste derived hydroxyapatite embedded on diglycolamic acid functionalized g-C3N4 (HAp@D-gCN) nanocomposite was prepared.•HAp@D-gCN could selectively adsorb U(VI) from aqueous solutions containing various metal ions.•HAp@D-gCN demonstrated a maximum adsorption capacity (qmax) of 993.6 mg g−1.•Adsorption equilibrium was achieved with a minimum contact time of 20 min.•HAp@D-gCN nanocomposite can be regenerated and reused for several adsorption-desorption cycles.