Eriochrome Black T dye removal from an aqueous solution using graphene oxide-modified activated carbon materials

ABSTRACT

The presence of a toxic anionic dye, like Eriochrome Black T (EBT) in the aquatic environment, is the major cause of water contamination. Considering this, we synthesised activated carbon, (AC) derived from the Carica papaya seeds, which is effective, low-cost, simple to design and with a higher surface area. The prepared materials (GO/AC) will be employed for the efficient removal of toxic EBT dye. The synthesised GO/AC composite was further analysed using FTIR, XRD, FE-SEM, EDX and Raman spectra. The adsorption performance of GO/AC materials towards EBT dye removal was checked through a batch adsorption experiment. Various parameters, including initial dye concentration, contact time, adsorbent dosage, stirring speed and pH, were batch-wise varied for the adsorption experiment. The higher correlation coefficient (R²= 0.99) indicated that the Langmuir isotherm model was followed by the experimental data suggesting that the adsorption process is a monolayer. The maximum adsorption capacity of EBT dye was found to be 51.84 mg/g. The pseudo-second-order kinetic model was well-fitted. The thermodynamic study suggested that the adsorption process is endothermic and spontaneous. Furthermore, the desorption efficiency of the GO/AC materials was tested through reusability in five cycles. An adsorption mechanism was also performed for the removal of EBT dye.

GRAPHICAL ABSTRACT

KEYWORDS:

• EBT dye
• activated carbon
• graphene oxide
• adsorption
• papaya seeds

Disclosure statement

No potential conflict of interest was reported by the author(s).