Efficient degradation of tetracycline in aqueous solution using a coupled S-scheme ZnO/g-C3N4/zeolite P supported catalyst with water falling film plasma reactor

To overcome the plasma system drawbacks, the hybrid system is used for the removal of pharmaceutical pollutants from effluents. In this study, the tetracycline (TC) removal from water was investigated using hybrid water falling film plasma-catalyst system. The ternary compounds nanocomposites containing zinc oxide (ZnO), nitride carbon graphite (g-C3N4), and zeolite with different ratios were synthesized at two stages using hydrothermal treatment method. Thereafter, the prepared nanocomposites were loaded on constructed plasma reactor equipped with the water falling film facility. The results of the characterization process confirmed that all synthesized nanocomposites had a suitable specific surface area, crystallinity, and the heterojunction formation ZnO with g-C3N4. The formation probability of S-scheme heterojunction structure of ZnO/g-C3N4 was discussed because of Fermi level’s difference between ZnO and g-C3N4. Under the suitable operational condition, 95.5% TC removal efficiency as well as 4.43 synergistic effects were obtained using the hybrid system. The TC removal for hybrid system was ascribed as 30% more than sole plasma system. Afterward, the stability tests confirmed the ideal reusability of the prepared nanocomposite. The scavenger addition satisfied that the roles of both •OH and hole were critical. A mechanism was proposed for the TC degradation in this fabricated system.