Green synthesis of AgCoFe2O4@Ch/AC as a recyclable, magnetic nanohybrid heterogeneous catalyst in photodegradation of ceftriaxone from aqueous solutions with effluent bioassay

Abstract Ceftriaxone (CFTR) is among the most commonly used antibiotics in the treatment of different types of bacterial infections and widespread pneumonias. It was also known as one of the most frequently prescribed antibiotics during the Corona pandemic. This drug has a longer half-life than other antibiotics. In this research, the heterogeneous magnetic nanophotocatalyst AgCoFe 2 O 4 @Chitosan(Ch)/activated carbon (AC) was synthesized by co-precipitation method under microwave waves. The catalyst structure was characterized by XRD, FTIR, FESEM, EDS, mapping, line scan, BET, VSM and DRS analyzers. Then, the effect of pH, CFTR concentration, nanophotocatalyst dose and irradiation time on the photocatalytic process efficiency was investigated. The analyses showed that the catalyst was synthesized on a nanometer scale, high surface area (60.044 m 2 /g), high magnetic strength (Ms = 10.39 emu/g) and appropriate optical activity with band gap (3.1 eV). The highest removal efficiency at pH = 3, CFTR concentration of 5 mg/L, dose of 0.24 g/L, and irradiation time of 60 min was obtained at 98.8% and 79.01% for synthetic and real wastewater samples, respectively. The reaction kinetics followed the pseudo -first-order and Langmuir–Hinshelwood kinetic models with K C = 0.23 mg/L min and K L−H = 0.168 L/mg. The recovered catalyst was able to remove CFTR with an efficiency of 80.16% after 4 reuse cycles. The results of scavenger radical tests showed that the main active radical species was $$^{ \cdot } {\text{OH}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mrow/> <mml:mo>·</mml:mo> </mml:msup> <mml:mtext>OH</mml:mtext> </mml:mrow> </mml:math> . The obtained results from the effluent toxicity on the germination index of lettuce, watercress, radish and tomato seeds showed a significant reduction in the environmental hazards of the effluent. Due to the high efficiency, this nanophotocatalyst can be used for the treatment of pharmaceutical and hospital wastewaters, and the effluent has the least toxicity for the environment.

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