Efficiency Assesment of Chitosan Graphene Oxide Composite in Aniline Removal from Aqueous Solutions

Background: Aniline is a toxic compound characterized by high solubility in water (3.5 percent; 35000 mg/l) leading to increased presence risk of aniline in wastewater. The presence of this compound in the blood causes the formation of met hemoglobin and prevent oxygen uptake and plays a key role in chemical asphyxiation, moreover, it has been thought as a carcinogenic risk factor to humans. Therefore, this study aims to synthesizes chitosan graphene oxide and determine the usefulness of using this absorbent to remove aniline from aqueous solutions. Methods: Chitosan Graphene Oxide (CGO) which was prepared from graphite powder by adapting the procedure used by Hummer, doped with chitosan and the characterization of CGO were determined by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Powder Diffraction (XRD). To optimize the conditions, parameters including adsorbent dosage (g / L 0/2, 0/4, 0/6, 0/8, 1, 1/25,1/5), pH (2, 4, 6, 8, 10), contact time (5, 15, 30, 45, 60, 90, 120 min) and aniline concentrations (mg/L 50, 100, 150, 200, 300) were evaluated in a total of 126 tests. Finally Chitosan Graphene Oxide was used for aniline removal from aqueous solutions. Results: The results of present study showed that with increase in contact time and absorbent dosage and with decrease in aniline concentration, removal efficiency tend to increase. PH=6, time=30min, absorbent dose=1 g/l and concentration of aniline=50 mg/l were obtained as optimum conditions. Under optimum condition (pH=6, time=30min, absorbent dose=1 g/l and concentration of aniline=50 mg/l) the highest efficiency of aniline removal is %93.14. The adsorption isotherm showed that absorption process correlates well with Langmuir adsorption isotherm (R2>0.9996). Reaction kinetics complies with Pseudo-second order model with correlation coefficient of (R2=0.9799). In the study of thermodynamics, negative values of ΔH0 and ΔG0 respectively illustrate that reactions are exothermic and spontaneous. Conclusion: chitosan graphene oxide composite has the ability to remove aniline effectively from aqueous solutions. And also it can be used as an efficient adsorbent for related aqueous solutions.