Removal of drug and dye from aqueous solutions by graphene oxide: Adsorption studies and chemometrics methods

Jingjie Yang,Siroos Shojaei,Saeed Shojaei

doi:10.1038/s41545-022-00148-3

Jingjie Yang, Siroos Shojaei + Show 1 more

Open Access

https://doi.org/10.1038/s41545-022-00148-3

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Abstract

Pharmaceutical products and dyes are the main environmental pollutants in the effluent of textile, cosmetic, and pharmaceutical industries. Therefore, in this study, the central composite design (CCD) based on the response surface methodology (RSM) was used to investigate the operating parameters and determine the optimal conditions for the removal of enrofloxacin (ENF) and Rhodamine B (RhB) by graphene oxide (GO). The structure and morphology of GO were studied using scanning electron microscopes (SEM) and X-ray diffraction (XRD) techniques. Quadratic model was confirmed to describe each of the removal efficiency responses (%R) a with high correlation coefficient (R2 = 0.9987 for ENF and R2 = 0.9999 for RhB) (R2-Adj = 0.9963 for ENF and R2-Adj = 0.9991 for RhB). In optimal conditions, RhB concentration of 10 mg L−1, adsorbent amount of 0.24 g, sonication time of 23 min, ENF concentration of 10 mg L−1, and pH 7, removal rates of more than 92.5% were obtained for both analytes. Adsorption equilibrium was studied with Langmuir, Freundlich, Langmuir-Freundlich, Redlich-Peterson, Toth and Khan isotherm models. Equilibrium data were best fitted with the Langmuir-Freundlich isotherm model. Maximum adsorption capacity of ENF and RhB on GO were 45.035 mg g−1 and 107.230 mg g−1, respectively. The recyclability of GO was evaluated during the ENF and RhB adsorption process. The results showed that up to 4 cycles of adsorbent, the adsorption efficiency is reduced by a tiny amount. The present study showed that GO is highly effective in removing ENF and RhB from environmental water samples.

Highlights

Nowadays, the excessive use of pharmaceutical products and dyes due to the entry of some of these compounds into the environment has raised concerns worldwide
This study showed that Cu2O/rGO nanocomposites could be successfully used to remove Rhodamine B (RhB) from aqueous solutions[29]
The results show that the values of ΔG° obtained from the thermodynamic study are negative and indicate that the nature of ENF and RhB uptake is spontaneous by graphene oxide (GO)

Summary

Introduction

The excessive use of pharmaceutical products and dyes due to the entry of some of these compounds into the environment has raised concerns worldwide. Enrofloxacin is a collaborative group of antibiotics in the production and consumption worldwide that is used to treat various infectious diseases in humans and animals[6] The presence of these drugs in the environment leads to the ecological toxicity and development of antibiotic-resistant pathogens that potentially threaten ecosystem function and human health[7,8]. RhB is used in various industries such as textile, printing, and leather industries[9] It is often used as a pigment routing in water to determine the direction and speed of transmission. The adsorption process using cheap and available adsorbents is one of the most efficient, easiest, and most economical methods for removing dye and drug[17,18] The advantages of this method are high efficiency, low operating costs, ease of use, and adaptation to the environment[19,20]. Since the adsorption performance is directly dependent on the quality and cost-effectiveness of the adsorbent, various attractions, including activated carbon[21], zeolite[22], clay[23], and graphene oxide (GO)[24], have been studied in recent decades

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