Column experimental study on the removal of hexavalent chromium from water by modified cellulose filter paper loaded with nano zero-valent iron

Based on our previous batch experimental research, sand column experiments of modified cellulose filter papers loaded with nano zero-valent iron composites (CFP-OH-nZVI) for the removal of hexavalent chromium (Cr(VI)) from porous media water were carried out to discuss and analyze the effects of the initial concentration of Cr(VI) (10, 20, and 40 mg/L), flow rate (1, 3, and 5 mL/min), and adsorbent dosage (0.76, 1.52, and 3.04 g) on the removal of Cr(VI). The Thomas and Yoon-Nelson models have shown good results in fitting and analyzing breakthrough curves. Through column dissection experiments, the elemental valence composition and spatial distribution of Cr and Fe within the column were elucidated, and the mechanism of Cr (VI) removal was analyzed. In addition, the two-site sorption chemical non-equilibrium model in Hydrus-1D effectively simulates the migration behavior of Cr (VI) in composite porous media under different conditions. This study may provide useful reference for the treatment of groundwater contaminated with heavy metals such as Cr (VI) using CFP-OH-nZVI. [Display omitted] •CFP-OH-nZVI was synthesized by a simple method to remove Cr (VI).•The performance of CFP-OH-nZVI in removing Cr (VI) in columns was clarified.•Possible mechanism of Cr (VI) removal by CFP-OH-nZVI in columns was elucidated.•Specific fitting performance of different kinetic models.•The migration behavior of Cr (VI) was effectively simulated using Hydrus-1D.