Synthesis of novel MnFe2O4/BiOI green nanocomposite and its application to photocatalytic degradation of tetracycline hydrochloride: (LC-MS analyses, mechanism, reusability, kinetic, radical agents, mineralization, process capability, and purification of actual pharmaceutical wastewater)

Antibiotics in water bodies pose a serious threat to public health and the environment, leading to increased efforts to eliminate them from wastewater. In this study, a green nanocomposite catalyst of MnFe2O4/BiOI and Calendula officinalis was evaluated for its ability to decompose tetracycline in simulated sunlight. Characterization techniques including DRS, DLS, VSM, FTIR, XRD, TEM, FESEM, EDX, LC-MS, and pHpzc were used, revealing MnFe2O4/BiOI 's average crystal size of 14.47 nm, band gap of 1.7 eV, and magnetic saturation of 23.63 emu/gr. Under optimal conditions of a pH level of 9, tetracycline concentration of 20 mg/L, MnFe2O4/BiOI dosage of 0.5 g/L, and a reaction time of 200 min, the MnFe2O4/BiOI catalyst effectively broke down tetracycline, resulting in complete degradation. The pseudo-first-order equation accurately predicted degradation rates, and reusability tests showed only a 5% drop in efficiency after six cycles. The recommended method achieved high mineralization rates, with COD and TOC elimination efficiencies of 83.04% and 61.45%, respectively. Maximum removal efficiency for TOC and COD in pharmaceutical wastewater was achieved after 200 min, with 44.73% and 57.19%, respectively. Under optimal conditions, with 20 mg/L of tetracycline and sunlight exposure, the maximum tetracycline removal rate was 76.02%. This study demonstrated that the MnFe2O4/BiOI catalyst-based Xenon-photocatalytic approach is effective and adaptable for treating wastewater containing antibiotics from drug production and manufacturing processes.