Assessing the performance of non-toxic nanomagnetic modified deep eutectic solvents for tetracycline adsorption: Taguchi approach for optimization

In this research, a relatively new and environmentally benign deep eutectic solvent (DES), composed of ethylene glycol and 1-butylimidazole, was chosen as a modifier in magnetic iron (II, III) oxide to produce novel and non-toxic nanomagnetic modified deep eutectic solvents (Fe3O4@DES). The Fe3O4@DES-2 exhibited unique properties that enabled rapid and efficient removal of four tetracycline compounds (TC, OTC, CTC, and DO) from water. The adsorbent was synthesized in situ using the co-precipitation method and its physical characteristics were determined through various analyses. Cytotoxicity studies confirmed the material's non-toxic nature and UV–Vis spectrophotometry was integrated with the Taguchi design statistical analysis for variable optimization. The method greenness was also evaluated according to AGREEprep and ComplexGAPI. The adsorption process was primarily driven by the synergistic effects of π–π bonding and hydrogen bonding interactions, which were conclusively validated through comprehensive characterization, kinetics, and isotherm studies. The thermodynamic parameters revealed that the adsorption process is exothermic, spontaneous, and feasible across all studied temperatures. The proposed approach for tetracyclines removal focuses on the guiding role of DES in selective adsorption. This green DES regulation idea provides more options for synthesizing high-efficiency and functional adsorbents for emerging pollutants.