Catalytic Ozonation Treatment of Biochemically Treated Leachate from Municipal Waste Solid Using Ti–Mn Oxide‐coated Stainless Steel Mesh Catalyst

BACKGROUND Landfill leachate is a kind of complex organic wastewater, the discharge standard of which is difficult to meet after traditional biochemical treatment. In this work, a Ti-Mn stainless steel corrugated wire mesh (SSCWM) catalyst was prepared by the sol-gel method, which was used for the catalytic ozonation of biochemically treated leachate. RESULTS The catalyst was characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy techniques. The data showed that the chemical oxygen demand (COD) removal efficiency of the leachate by ozone alone, SSCWM/O-3,O- Ti-SSCWM/O-3 and Ti-Mn/SSCWM/O-3 system reached 55.06%, 64.44%, 68.97% and 78.43%, respectively. The catalytic effect of different layers of Ti-Mn oxide-coated SSCWM catalyst showed that two catalytic layers had the best activity of COD removal efficiency, reaching 87.17%, and the final COD reached the national emission standard (<100 mg L-1). At the same time, the results of fluorescence spectrum and gas chromatography-mass spectrometry (GC-MS) analysis confirmed this point. The stability of the catalyst decreased with the increase in usage times, and the final COD removal efficiency was 73.91% after six cycles of use. To understand the reason for catalyst deactivation, the adsorbed organic matter on the catalyst surface was determined by GC-MS analysis. In addition, COD removal of the catalyst can be increased to 80.55% after in situ regeneration of the mesh catalyst by a sequential cleaning process consisting of alkali-acid-hydrogen peroxide-ethanol-water. CONCLUSION In short, application of the mesh catalyst in catalytic ozonation can be considered as a promising method for wastewater treatment, because of avoidance of solid-liquid separation and easy regeneration of catalytic activity. (c) 2020 Society of Chemical Industry