Optimization of Fenton Degradation Treatment of Liquid Scintillation Waste by Response Surface Methodology

Response surface methodology(RSM) was employed to obtain the optimization experiment conditions of the Fenton degradation treatment of liquid scintillation waste. 5 factors central composite design with RSM was used, in which the factors are FeSO₄ concentration, H₂O₂ concentration, pH, time and temperature, while the waste sample’s total COD removal rate was chosen as the response. Coefficient of determination R² is 0.938 1 and adjust coefficient of determination R²_Adj is 0.880 1, which indicate that the model fits well and predicates the Fenton degradation process well. The optimal experiment conditions are that the initial Fe²⁺ concentration is 0.99 mmol/L, and the initial H₂O₂ concentration is 57.50 mmol/L, and pH is 2.48, and  the temperature is 76.59 ℃, and the reaction time is 68.53 minutes. Under these optimal experiment conditions, the predicted maximum COD removal rate is 87.19%, and the actual COD removal rate of the waste sample is 85.81% (n=3). The relative error is 1.58%, which indicate that RSM is suitable for the design and optimization of the Fenton oxidation processes.