Using SiO-Supported MnO@FeO Composite to Catalytically Decompose Waste Drilling Fluids Through Fenton-like Oxidation.

Waste drilling fluids produced from oil extraction can cause serious harm to the ecological environment; thus, the treatment of waste drilling fluids is urgent and important to ensure the sustainability and development of the oil extraction. In this work, we used the Fenton-like reaction method to degrade waste drilling fluids with SiO-supported MnO@FeO composite material as a catalyst in the presence of HO. During the Fenton-like reaction process, the MnO@FeO interface exhibits exceptional activity by facilitating the production of ·OH species with high activity and strong oxidizing properties, which degrade the organic substances in the waste drilling fluids into smaller inorganic molecules, thereby reducing its COD value. Compared to the reaction only with HO, after reacting with sufficient SiO-supported MnO@FeO catalyst for 4 h at 60 °C in the presence of HO, the COD value of the waste drilling fluids is reduced by 36,495 mg L, a decrease of more than 95%. This performance is significantly superior to that of the traditional Fenton reagent FeSO, which reduced the COD by 32,285 mg L, a decrease of 84%. This work provides an important composite catalyst, which is practically useful for the treatment of waste drilling fluids.