The researchers studied how to treat drilling wastewater using a combination of O3 oxidation and Fenton oxidation. They found that by adjusting the pH and reaction times, they could achieve a high removal efficiency of contaminants in the wastewater. Specifically, when the initial pH for O3 oxidation was 11 and the reaction time was 50 minutes, and the Fenton reagent had an initial pH of 3 and an oxidation time of 3 hours with specific amounts of H2O2 and FeSO4, they were able to achieve a CODcr removal efficiency of 98.3%. Adjusting these parameters based on the water quality can help achieve the best treatment results.