Removal of paracetamol from aqueous solution with zinc oxide nanoparticles obtained by green synthesis from purple basil ( Ocimum basilicum L.) waste

In this study, environmentally friendly zinc oxide nanoparticles (OB-ZnO NPs) were synthesized using Ocimum basilicum (OB) plant waste extract, and the removal of paracetamol (PCM) from pharmaceutical wastes with toxic effects on the ecosystem was investigated. The characteristic structure of synthesized OB-ZnO NPs was determined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM) and energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), Zetasizer, thermogravimetry-differential thermal analysis (TGA-DTA), and UV-vis spectroscopy. The effect of the obtained OB-ZnO NPs on PCM removal was determined by batch adsorption tests. In the study in which 6 different kinetic and isotherm models were examined, error analysis functions were used to determine the most suitable model. Accordingly, the crystal structure of biosynthesized OB-ZnO NPs has a particle size of 30.39 nm, a surface area of 13.826 m 2 /g, and a pore volume of 0.0475 cm 3 /g. Since OB-ZnO NPs have a zeta potential of − 22.1 mV and a mass loss of 33% at about 750 °C, these NPs show that they are durable at high temperatures. When the PCM removal mechanisms with OB-ZnO NPs were examined, it was determined that the most suitable kinetic and isotherm model was the Elovich model with an R 2 value of 0.989 and the Redlich-Peterson model with an R 2 value of 0.999. In the study, which reached 23 mgPCM/gOB-ZnO NP removal efficiency, it was revealed that OB-ZnO NPs obtained from waste plants have the potential to be used in the removal of pharmaceutical wastes. Graphical abstract