Characterization and Preliminary Evaluation of CuO, FeS₂, and Zeolite Y for Tetracycline Adsorption from Simulated Hospital Wastewater

Tetracycline (TC), a widely used antibiotic, is frequently detected in wastewater effluents, raising concerns about environmental persistence and antibiotic resistance. In this study, the adsorption potential of copper oxide (CuO), iron disulfide (FeS₂), and zeolite Y (HY) was preliminarily assessed for TC removal from aqueous media. CuO and FeS₂ were synthesized via precipitation and hydrothermal routes, respectively, while ammonium zeolite Y was calcined at 550 ℃ for 3 hours to obtain Zeolite HY. The three adsorbents were characterized using FTIR, XRD and SEM-EDX techniques. The FTIR result showed the functional groups at the fingerprint wavebands; Cu-O stretching vibration was seen at 500 – 600 cm^-1, Fe-S vibrational mode was observed at 430-470 cm^-1 and the Si-O-Si / Al-O-Al asymmetric stretching of the framework of Zeolite HY was seen at 1000-1100 cm^-1. The XRD method displayed the characteristic peaks of the individual components while the SEM images of CuO and FeS₂ showed aggregated irregular-shaped particles and flat sedimented particles, respectively. Elemental compositions were illustrated from SEM-EDX, showing the presence and composition of individual element of CuO and FeS₂. All three adsorbents were tested for adsorption in the dark under varying conditions: adsorbent dosage (0.2–1.2 g/20 mL), pH (3–13), contact time (30–150 min), and initial TC concentrations (20–140 mg/L). CuO achieved a maximum TC removal efficiency of 91.4% at pH 9 with 0.6 g/20 mL dosage after 120 minutes, following pseudo-second-order kinetics. For FeS₂, dosage variation showed an increasing trend in removal, peaking at 81.2 % with 1.2 g/20 mL, but performance declined sharply under acidic and basic conditions, likely due to pH-induced surface instability. The HY zeolite also exhibited high adsorption (89.4 % at 0.6 g/20 mL). These results suggest all as promising adsorbents for TC, with FeS₂ and HY showing potential for integration into composite materials.