Catalytic chemical reduction of Cr(VI) from contaminated waters by the production of hydrogen radical on the cellulose sulfate microfibers coated with palladium nanocatalyst

Abstract

In this study, the removal of Cr(VI) from contaminated waters was studied via a chemical reduction of Cr(VI) on cellulose sulfate microfibers coated with palladium nanocatalyst. In this catalytic procedure, hydrogen gas was generated utilizing an electrochemical cell containing graphite electrodes. Characterization of the prepared catalyst was done using scanning electron microscopy, energy-dispersive X-ray analysis, Fourier-transformed infrared spectroscopy, and thermalgravimet- ric analyses. The Box–Behnken model of response surface methodology was used to optimize the adsorption process. The effects of main variables including current density, initial concentration of Cr(VI), and time and their interactions on the removal efficiency of Cr(VI) were assessed. Under the optimal conditions (0.1 A and 15 min), the removal efficiency of 98% was achieved for Cr(VI). The examination of recovery indicated that the performance of the prepared catalyst decreased about 10% after 10 cycles of usage.