An easily applicable and recyclable Fenton-like catalyst produced without wastewater emission and its performance evaluation

Abstract

A thin disc-shaped Fenton-like catalyst sized 28.59*1.39 mm in diameter and thickness was produced by ball milling a hemi-dried silica xerogel with iron (III) acetylacetonate, followed by mold pressing and calcination. The developed compact catalyst facilitated its application and recovery. The whole fabrication process was free of wastewater emission. Plasticizers or binders indispensable for shaping commercial powders into compact green bodies were not necessary in the present method. The bulky catalyst was mesoporous and had a large surface area of 580 m2/g, providing access to the activation of H2O2 by the active iron sites inside the sample. It removed 100% of methylene blue (MB) in solution with a total TOC reduction by 92.13% mainly via the Fenton degradation. No washing, chemical elution of the adsorbed dye before the next application was applied. After five cycles, ca.93% of the removal efficiency was maintained. The TOC reduction increased from the 1st to 3rd cycle and ca.88% of the initial capacity was kept after the 5th cycle, while the iron leaching was only 0.021% of the applied catalyst. The excellent performance of the bulky catalyst was due to its large surface area, uniformly distributed and chemically bonded iron species. The present work provides a scalable and green way to produce Fenton-like catalysts for environmental application.