Adsorption of azithromycin pharmaceutical by polypyrrole and polypyrrole/zinc ferrite@magnetite (PPy/ZnFe₂O₄@Fe₃O₄) adsorbents synthesized from deep eutectic solvent: Kinetic, isothermic, and thermodynamic

The aim of this study was to use novel polypyrrole (PPy)/zinc ferrite@magnetite (PPy/ZnFe 2 O 4 @Fe 3 O 4 ) and PPy compounds as adsorbents to remove azithromycin (AZM) from aqueous solutions. These adsorbents were made by chemical polymerization in a deep eutectic solvent (DES) known as oxaline. A range of techniques, such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), vibrating sample magnetometer (VSM), Brunauer-Emmett-Teller (BET), and zeta potential, were employed to comprehensively evaluate the synthesized adsorbents. Additionally, adsorption tests were conducted to examine the influences of AZM concentration, pH, contact duration, and adsorbent dose. The ideal results indicate that AZM removal effectiveness was 62.3% for PPy and 98.5% for PPy/ZnFe 2 O 4 @Fe 3 O 4 under the following conditions: pH 6, with 80 mg of PPy and 60 mg of PPy/ZnFe 2 O 4 @Fe 3 O 4 adsorbents, a drug concentration of 100 mg/L, and stirring for 180 min. The adsorption process was thoroughly investigated using the kinetic and isothermal models. The pseudo-second-order kinetic and Langmuir models were identified as the most accurate representations of AZM adsorption for both adsorbents at 298 K. Additionally, the data demonstrated that pure PPy had an adsorption capacity of 80.13 mg/g, but the PPy/ZnFe 2 O 4 @Fe 3 O 4 nanocomposite had a high adsorption capacity of 183.73 mg/g. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. The adsorbent exhibited exceptional regenerative properties, allowing for reuse throughout five cycles. The study also investigated the adsorption of AZM medicines from real tablet samples utilizing the PPy/ZnFe 2 O 4 @Fe 3 O 4 nanocomposite. These results showed the good absorbent capacity of PPy/ZnFe 2 O 4 @Fe 3 O 4 in the efficient removal of AZM from water sources.