Photocatalytic degradation of N‐nitrosodiethylamine from carbon capture plants using tungsten trioxide‐based catalysts: Parametric and optimization study

Abstract This study reports the synthesis and characterization of tungsten trioxide‐based catalysts for the photocatalytic degradation of N ‐nitrosodiethylamine (NDEA) in wastewater. Tungsten trioxide (WO 3 ) was synthesized using the thermal treatment method (TTM) and hard template replication method (HTRM) and impregnated with lanthanum (La), iron (Fe), chromium (Cr), and silver (Ag) to enhance its light absorption ability. The synthesized catalysts were characterized using various techniques, including UV‐Vis spectroscopy, Brunauer–Emmett–Teller (BET), Barrett–Joyner surface area and porosity, X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). The experimental design approach used a response surface methodology (RSM) with a face‐centered central composite design (FCCCD) technique. Catalyst loading (%), pH of solution, and catalyst concentration (g/L) were chosen as design factors, with the response variable being NDEA degradation efficiency (%). The obtained data were analyzed, and a quadratic model was chosen as the best fit with statistically significant model terms as observed from the analysis of variance (ANOVA). 3D interaction plots were generated to explain the effect of the various interaction terms of the quadratic model. The results showed that the pH of the solution was the major factor affecting NDEA degradation efficiency. The mean degradation efficiency of NDEA was 93.03% for Fe/WO 3 , 88.90% for Ag/WO 3 , 86.48% for La/WO 3 , and 84.03% for Cr/WO 3 . These findings demonstrate the potential of tungsten trioxide‐based catalysts impregnated with various metals for the effective treatment of NDEA in wastewater through heterogeneous photocatalysis.