Integration of Polydopamine and Fe₃O₄ Nanoparticles with Graphene Oxide to Fabricate an Efficient Recoverable Catalyst for the Degradation of Sulfadiazine

Contamination of water resources with antibiotics is an emerging environmental issue. This research reports the prosperous preparation of magnetic graphene oxide-polydopamine (M-GO-PDA) nanocomposite for sonocatalytic degradation of sulfadiazine (SDZ) as a model antibiotic pollutant from the aqueous solution. The physicochemical characteristics of the synthesized catalysts were analyzed by identification analyses including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FT-IR), and Diffuse reflectance spectroscopy (DRS). After the operational variables optimization, the highest sonocatalytic degradation of SDZ (93.1%) was obtained using 0.45 g/L catalyst, 0.16 mM SDZ, and an ultrasonic power of 300 W at pH 6.8 (natural) within 60 min. Based on the observed data and GC-MS analysis, a possible sonocatalytic mechanism for the sonochemical degradation of SDZ in the presence of M-GO-PDA was proposed. Chemical oxygen demand (COD) removal efficiency of 79.4% and the considerable increase in the concentrations of SO42-, NH4+, and NO3- ions proved the effective mineralization of SDZ within 180 min sonocatalysis.