Photocatalytic Degradation of Tetracycline in Wastewater with Bio-based Matrix Magnetic Heterogeneous Nanocatalyst: Performance and Mechanism Study

Abstract

Tetracycline (TC), a widely used antibiotic, can easily enter aquatic ecosystems through soil erosion, livestock manures, and wastewater discharge, causes environmental and ecological health effects. AgCuFe₂O₄@Methylcellulose (MC)/Activated Carbon (AC) magnetic nanocomposite was synthesized accompanied by microwave-assisted co-precipitation procedure under green circumstances with high efficiency and subsequently utilized as a new heterogeneous magnetic nano-photocatalyst in the TC photodegradation from aqueous solutions. The structural characterization of AgCuFe₂O₄@MC/AC was performed by various analytical techniques. Afterwards, the key parameters of the photocatalytic TC degradation process, such as catalyst dose, TC concentration, pH, and process time, were investigated and optimized the results showed that the catalyst was synthesized on a nanometer scale (25 nm) with a quasi-spherical structure, with a high specific surface area, high magnetic strength (Ms = 19.27 emu g⁻¹), and the preservation of the crystal structure. The removal efficiency of TC under optimal conditions including pH 7, initial TC concentration of 5 mg L⁻¹, nano-photocatalyst dose of 0.5 g L⁻¹, 90 min of irradiation time was reported to be 90.91% for synthetic sample and 87.17% for real wastewater sample. The removal effectiveness of total organic carbon was 85.2% under optimal conditions. The photocatalytic degradation kinetics of TC followed pseudo-first-order and Langmuir–Hinshelwood kinetic models, with values of K_L–H = 0.633 L mg⁻¹ and K_c = 0.126 mg L⁻¹ min⁻¹. After four cycles of recovery and regeneration, the synthesized catalyst demonstrated high chemical stability and was able to remove 62% of the pollutant. Finally, this study provides a viable approach for removing antibiotics using an AgCuFe₂O₄@MC/AC-based heterogeneous nanostructured photocatalyst.

Graphical Abstract