The effect of iron-loaded chitosan on the removal of Reactive Orange 16 dye

Abstract

The aim of the study was investigation of Reactive Orange 16 (RO16) textile dye removal with developed iron modified chitosan (CSFe) adsorbent materials. Productions of CSFe adsorbents were carried out with 0.5 mg/L chitosan and 250, 500 and 750 mg/L [Fe+2] concentrated 500 mL FeSO4 solutions at 25 degrees C for 2 hours at 250 rpm and iron-modified adsorbents were named as CSFe-1, CSFe- 2 and CSFe-3. Adsorption studies were conducted by using 0.5 g/L adsorbent to remove of 50 mg/L RO16 dye solution for 2 hours. Purpose: Development of iron modified chitosan adsorbent materials and determination of the adsorption effects of these adsorbents with the removal of RO16 textile dye was aimed in this study. Theory and Methods: 0.5 mg/L chitosan was placed in 250, 500 and 750 mg/L [Fe+2] concentrated 500 mL FeSO4 solutions were shaken at 25 degrees C for 2 hours at 250 rpm in order to determine the amount of maximum iron loading capacity on chitosan. Iron-modified adsorbents were used to examine the effect of RO16 dye removal. Using the adsorption equilibrium equation, the amount of Fe+2 adsorbed per unit chitosan was calculated as 79, 112 and 110 mg/g for CSFe-1, CSFe-2 and CSFe-3. The SEM, EDS and FT-IR analysis were applied on the ironmodified adsorbents. In order to determine the optimum adsorption conditions for CSFe-1 adsorbent in the RO16 dye removal process, the amount of adsorbent (0.25, 0.5 and 1 g CSFe-1/L), shaking speed (250 and 350 rpm), dye solution concentration (25, 50 and 100 mg/L) and temperature (25 and 50 degrees C) were investigated. Results: The amount of Fe+2 adsorption capacity values of iron-modified adsorbents (CSFe-1, CSFe-2 and CSFe-3) were calculated as 79, 112 and 110mg/g, respectively. The CSFe-1 and CSFe-2 adsorbent materials were selected to examine the effect of RO16 dye removal. In adsorption studies, the dye removal efficiencies were achieved as 25 and 90% for pure and iron modified chitosans. The 0.5 g CSFe-1/L adsorbent amount, 250 rpm shaking speed, 25 degrees C and 50 mg/L dye solution concentration were determined as optimum adsorption conditions and 92% color removal efficiency was obtained under the conditions. Conclusion: The dye removal efficiencies were achieved as 25 and 90% for pure and iron modified chitosans. Moreover, the maximum adsorption capacity of pure and modified adsorbents for RO16 dye solutions was calculated as 27, 91 and 88 mg/g, respectively. It was observed that RO16 adsorption capacity and decolorization efficiency increased by iron modifying chitosan up to 70% and it can be used in dye removal.