Phosphate Adsorption from Solution by Zirconium-Loaded Carbon Nanotubes in Batch Mode

• Published in: Journal of chemical and engineering data Vol. 64; no. 6; pp. 2849 - 2858
• Main Authors: Gu, Yifan, Yang, Mengmeng, Wang, Weili, Han, Runping
• Format: Journal Article
• Language: English
• Published: American Chemical Society 13.06.2019
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/acs.jced.9b00214

A highly effective zirconium-modified carbon nanotube (Zr-CNTs) adsorbent was prepared to remove phosphate (PO4 3–) from solution in batch mode. Characterizations of Zr-CNTs were analyzed using FTIR, TEM, XRD, XPS, and Raman techniques. The effects of solution pH, ionic strength, phosphate concentration, and contact time on adsorption quantity were presented. The acidic solution was beneficial to the adsorption of PO4 3– on Zr-CNTs. There was no significant effect with coexisting anions such as Cl– and SO4 2–. The adsorption quantity was 10.9 mg·g–1 (according to P element) at 303 K. The adsorption isotherms were better fitted by the Freundlich model, whereas the kinetic data were better correlated with the Elovich model, which suggested that the adsorption process may be chemical adsorption. The adsorption of PO4 3– was a spontaneous, entropy-increasing, and endothermic process. XPS analysis showed that the complexation between Zr-CNTs and PO4 3– was the main adsorptive mechanism. In addition, the adsorbed PO4 3– was effectively desorbed by 0.010 mol·L–1 NaOH solution. This adsorbent has important potential for removal of PO4 3– from solution.