Simultaneous Removal of NOx and SO2 from Smelting Flue Gas Using Thermally Modified Copper Slag: Factor Optimization via Response Surface Methodology

Graphical In this study, we prepared the thermally modified copper slag catalyst CS-CaO-900 and applied it to a pilot-scale Fenton-like denitrification system. In single-factor experiments, the effects of six factors, namely inlet NO concentration, H 2 O 2 concentration, catalyst dosage, reaction temperature, L/G ratio, and pH value, on desulfurization and denitrification were investigated. Through analysis of the experimental results, the three factors that had the greatest impact on the maximum denitrification efficiency, namely pH value, H 2 O 2 concentration, and reaction temperature, were selected. The response surface methodology was employed to investigate the significance of the three factors and optimize the parameters, and it was finally determined that the initial pH of the slurry had the greatest impact on the maximum denitrification efficiency, followed by the H 2 O 2 concentration. At the same time, the combination of initial slurry pH and reaction temperature, initial slurry pH and H 2 O 2 concentration also had a large impact on the maximum denitrification efficiency, and the combination of reaction temperature and H 2 O 2 concentration had a non-significant impact on the denitrification efficiency. And through the model optimization to get the best parameters, denitrification experiments under this parameter to achieve the maximum denitrification efficiency of 91.5 %, for further industrial application to provide reference and guidance. In this study, Response Surface Methodology (RSM) was employed to optimize the experimental factors influencing the simultaneous removal of NOx and SO 2 in a spray tower wet scrubbing experiment. Thermally modified copper slag (CS-CaO-900) was prepared by heat treating the original copper slag. The performance of CS-CaO-900 in the synchronized removal of NOx and SO 2 was then evaluated in an expanded experimental setup. Based on single-factor experimental results, the Box-Behnken design of RSM was used to optimize the reaction parameters in a two-stage sequential reactor (bubbling reactor + spray tower). NOx removal efficiency was modeled as a function of reaction temperature, pH, and H 2 O 2 concentration. Regression curves provided a visual representation of the interaction effects among these parameters on NOx removal efficiency in the thermally modified copper slag/H 2 O 2 composite slurry. This study elucidates the characteristics of each parameter under wet scrubbing conditions and provides essential data for industrial applications.