Removal of selective serotonin reuptake inhibitor using magnetic graphene oxide derivatives: Adsorption study in low drug concentration using HPLC quantification, in vitro safety, and phytotoxicity

Abstract

Citalopram (CIT) is a drug widely used around the world in the treatment of depression. Due to the high toxicity of CIT and the failure of the methods used in treatment plants to purify water, the removal of this pollutant from the environment is very necessary. In this study, the removal of CIT was performed using graphene oxide (GO) and magnetic graphene oxide (GO·Fe3O4 1:1, 1:5, and 1:10). Moreover, the adsorption of CIT was accomplished at low drug concentrations, and the safety of biological and phytological adsorbents was investigated. The characteristics of the adsorbents were analyzed through SEM and TEM images, XRD, EDS, XPS, FTIR, Raman, VSM and the analysis revealed the spectra and signal characteristics of GO and GO·Fe3O4. The GO·Fe3O4 1:1 showed the highest adsorption capacity of 97.92 mg g−1 and removal percentage (98%). The pH, initial concentration, and glucose natural organic matter did not significantly affect the adsorption. The ionic strength and high dosages of GO·Fe3O4 1:1 disfavors the adsorption. Pseudo-second-order (PSO) and Liu models suggest that adsorption occurs at heterogeneous surfaces. The thermodynamic study confirms that CIT adsorption onto GO·Fe3O4 was spontaneous and exothermic. The in vitro assays evidenced that the complex, after adsorption, decreases the genotoxicity and the oxidative stress caused by CIT. Finally, the complex after adsorption does not show phytotoxic for L. sativa seeds. These findings have significant relevance for the safe use of GO·Fe3O4 1:1, allowing the employ in water remediation processes and their biocompatibility for biological applications.