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The advanced oxidation process of peroxymonosulfate activated by solid catalyst is one of the main technologies to solve the pollution of antibiotics in water environment.In this work, a series of composites (MCW) containing Mn, Co, and W were synthesized using green ball milling, which does not produce the three wastes (waste gas, waste water and industrial residue). It shows a unique and high catalytic activity for peroxymonosulfate-based degradation of doxycycline (DC) under the pH condition between 4 and 9, and it can be reused five times. MCW composites remove DC using singlet oxygen and superoxide free radicals, as well as a large number of oxygen vacancies for electron storage. The formation rate of free radicals is determined by the conversion rates of Mn 3+ /Mn 2+ and Co 3+ /Co 2+ . In addition, there are three ways to degrade DC to form 18 kinds of intermediates, and the toxicity of all the intermediates were predicted by ECOSAR program. The highly active catalysts obtained using a green synthetic route for the activation of peroxymonosulfate show a great potential for decontamination of antibiotics wastewater., (Copyright © 2021 Elsevier B.V. All rights reserved.)

[Display omitted] • A new approach to degrading antibiotics does not rely on oxidants or light. • Excellent degradation performance of doxycycline was achieved in a wide pH range. • The mechanism of direct catalytic degradation of doxycycline was deciphered. • A detailed degradation pathway of doxycycline via dark catalysis was proposed. Direct heterogeneous catalysis is conducted to decontaminate antibiotic polluted water for the first time. Perovskite-structured composites La x Sr (1- x) CoO 3-δ (LSC) are synthesized by a green mechanical milling method (as it involves no organic solvent, generates no wastewater, and is viable for industrial-scale use) and applied for the efficient catalytic degradation of doxycycline (DC) via singlet oxygen without the addition of chemical reagents or illumination. The oxygen vacancy produced during ball milling stores numerous electrons. These electrons and singlet oxygen exert a synergistic effect on the catalytic reaction, thereby improving the catalytic degradation of DC. LSC can effectively catalyze the degradation of DC in the dark. The total organic carbon removal efficiency reaches 89.64%, indicating that most DC is eventually mineralized to CO 2 and H 2 O. The catalytic degradation of DC follows two principal degradation pathways involving 13 intermediates. Toxicity prediction indicates that the toxicity of the products initially increases and then decreases with the degradation process and that the final products are not toxic. This study not only allows a facile synthesis route for catalyst preparation but also promotes the development of a green method for wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vermiculite as particle electrodes improved the efficiency of 3D electrode system. • The O 2 evolution side reactions was inhibited in the 3D electrode system. • The optimal operating conditions were obtained through parameter optimization. • A possible pathway for doxycycline degradation by the 3D system was proposed. In this study, vermiculite (VER) powder was used as a particle electrode in a three-dimensional (3D) Ti-IrO 2 /Ta 2 O 5 electrode system for the electrochemical degradation of doxycycline (DOX) combined with peroxymonosulfate (PMS) activation. The effects of operational parameters (such as VER dosage, PMS concentration, initial pH, and current density) on DOX degradation were studied and the optimal parameters were discussed. Electrochemical degradation and electrochemical analysis showed that the addition of VER particles could improve the electrochemical conversion efficiency of the 3D electrochemical system by increasing the oxygen evolution potential and inhibiting the occurrence of oxygen evolution side reactions. Quenching experiments showed that sulfate free radicals are the leading reactive oxygen species in the system. A possible pathway for DOX degradation by the reaction system was proposed based on intermediates detected using liquid chromatography–electrospray ionization–quadrupole–time of flight (LC–ESI–Q–TOF). The toxicity of all the intermediates was predicted using the ECOSAR program. Our study showed that the 3D VER/PMS electrode system was reliable for repairing surface water or groundwater polluted by antibiotics. [ABSTRACT FROM AUTHOR]