Removal of Thioflavin T and Co(Ii) Ions From Aqueous Solution Using Go and Go- Edta; Adsorption Parameters and Mechanism

Abstract

Dyes and heavy metals are typical pollutants causing environmental problems. In this study, the efficiency of GO and GO-EDTA used as adsorbents for Thioflavin T (TFT) and Co(II) metal ion removal from aqueous solution under optimum conditions was investigated. GO-EDTA was characterized by DR-UV/VIS, Raman spectra, FTIR and zero charge points (pHpzc) were determined using pH drift method. The maximum adsorption capacities (qM) of the adsorption process according to the Langmuir isotherm model, one of the isotherm models, refer to GO or GO-EDTA; It is 389.3178 mg g(-1) and 1009.5300 mg g(-1) for TFT dye, 736.9153 mg g(-1) and 1304.3525 mg g(-1) for Co(II) ion (pH=7, t=150 min, 298 K). The kinetic data fit the pseudo-second order model quite well. In the desorption graph, TFT dye desorption was observed to be quite efficient, while the reason for the decrease in the desorption of Co(II) ion was considered to be the strong bond formed as a result of ion exchange at the-COONa end in the EDTA structure. It was supposed that pi-pi interactions with benzene rings in GO and GO-EDTA structure, hydrogen bonding with functional groups on the structure and electrostatic interactions as a result of ion exchange at the carboxylic acid ends were generally effective in the adsorption mechanism. In conclusion, it was shown that GO and GO-EDTA nanomaterials can be effectively used as advanced adsorbents instead of traditional adsorbents for the removal of organic and inorganic pollutants from aqueous solution.