Application of wheat bran as a natural adsorbent for removal of Cr(VI) from aqueous solutions

In this study, the possible use of wheat bran as an adsorbent for Cr(VI) removal from synthetic solutions was investigated. The effect of parameters such as contact time and pH of solution on adsorption process was studied too. The Results of this study showed that the adsorption of chromium by wheat bran reached to equilibrium after 60 minutes and after that a little change of chromium removal efficiency was observed. The maximum removal of Cr(VI) occurred at pH of 2. With decreasing the pH of solution from 7.0 to 2.0, the removal of chromium was enhanced from 3% to 87.8%. The Langmuir, Frendlich and DR isotherms were fitted to equilibrium data and the isotherm constants for adsorption of chromium(VI) on wheat bran were calculated. The maximum monolayer adsorption capacity was determined to be 0.942 mg/g for experimental conditions in this study. Obtained results showed that adsorption behavior of wheat bran could be described reasonably well by Langmuir model with correlation coefficient of 0.997. In addition, the adsorption process was found to follow a pseudo-second-order rate. The results indicate that wheat bran can be employed as a low cost and effective alternative to commercial adsorbents in the removal of Cr(VI) from polluted solutions.

کلیدواژه ها:

Adsorption ، Chromium (VI) ، Wheat bran ، Adsorption isotherm ، Adsorption kinetics