Background and purpose: Various contaminants are released into water resources each year as a results of urbanization and industrialization. Chromium VI is one of the most toxic metals released into the aquatic environments, wastewater, and soil mainly via industrial sewage. The purpose of this study was to evaluate the performance of iron-zirconium/chitosan magnetic nanoparticles composite in removal of hexavalent chromium VI from aquatic environments.

Materials and methods: A pilot-study was conducted in laboratory scale. Nancomposites synthesis was done using chemical precipitation and tested by SEM, XRD, and FTIR. Various factors such as contact time (0-720 min), initial pH of the solution (2-12), adsorbent dose (0.4-2 gr), initial concentration of metal (0-10 milligrams per liter), and the system temperature (15-35 ℃) were studied. The concentration of heavy metal chromium was measured using a spectrophotometer at 540nm.

Results: The results showed that the highest removal efficiency of heavy metal chromium was obtained at pH 4.0 (52.99%). Moreover, addition of 1 gr composite in the same concentration could boost removing the hexavalent chromium by more than 91%. Increasing the concentration levels of heavy metals had little impact on the removal efficiency. Adsorption isotherms fitted the Freundlich isotherm.

Conclusion: According to the results, the absorbent showed a high performance in removing chromium VI from aquatic environments.