Effect of Chemical Oxidation on the Adsorption Properties of Cationic Dye on Activated Carbons Prepared from Locally Atropa belladonna

Rashwan, Wafaa Ezz Eldien; El-Nabarawy, Thoria; Aboelenin, Reham M; Fathy, Nady A

doi:10.21608/ejchem.2018.2954.1259

Effect of Chemical Oxidation on the Adsorption Properties of Cationic Dye on Activated Carbons Prepared from Locally Atropa belladonna

Document Type : Original Article

Authors

¹ National Research Centre Physical Chemistry Department, Faculty of Science, Cairo University

² Physical chemistry department, inorganic chemical industries division

³ National Research Centre

⁴ Physical Chemistry, Inorganic chemical industries division, National Research Centre,

10.21608/ejchem.2018.2954.1259

Abstract

This study investigates the influence of wet chemical oxidation using nitric acid and ammonium persulfate on the surface nature and the adsorption properties of activated carbon prepared from sulfuric acid activation of locally Atropa belladonna plant at 200oC. The surface properties of produced carbons (AC-S, AC-S/N and AC-S/A, respectively) were demonstrated by FTIR, potentiometric titration and N2 adsorption. The adsorption properties of these carbons were estimated using methyl green (MG) dye as a cationic dye. The effect of variables including pH, initial dye concentration and contact time on the adsorption properties of these carbons was studied. Acidic carbon adsorbents were obtained with large content of acidic surface functional groups in the sequence order AC-S<AC-S/N<AC-S/A as confirmed by FTIR and potentiometric plots. It was assessed that a large number of basic functional groups were generated after oxidation with ammonium persulfate (AC-S/N) and hence led to a decrease in its adsorption capacity towards MG dye. High adsorption capacities were found to be 100, 200 and 125 mg/g from MG dye onto AC-S, AC-S/N and AC-S/A, respectively. The adsorption results show that the adsorption was pH dependent with a high adsorption at pH of 6 which is obviously pH of dye solution. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and FlorryHuggins isotherm models. Pseudo-second-order kinetic model and Langmuir isotherm model showed better fit to the adsorption of MG dye onto the prepared carbons. Overall, this study reveals that the obtained carbons from Atropa belladonna are effective adsorbents in removing dyes from wastewater sources. Finally, the results also suggest that oxidation treatment with nitric acid is more efficient than ammonium persulfate to produce high acidic carbon adsorbents.

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