Degradation of wastewater from carbon capture plants using metal‐impregnated TiO2 photocatalyst

Abstract

AbstractAmine‐based carbon capture (ABCC) is an advanced and cost‐effective technology used to reduce the effects of climate change by capturing emitted from different sources. Although it has been demonstrated commercially, amine degradation poses a significant threat to humans and aquatic life. Amine degradation produces a wide variety of complex products such as nitrosamines and some organic acids. Some of these products are carcinogenic and mutagenic in nature and have demonstrated acute toxicity for laboratory animals. In order to mitigate the adverse impact of these compounds on human health and aquatic life, heterogeneous photocatalysis, an advanced oxidation process which can degrade a wide variety of chemical species with potent reactive hydroxyl radicals, was considered for the degradation of these compounds. The photocatalytic degradation of N‐nitrosodiethylamine (NDEA), acetic acid, and formic acid were tested using TiO2 and metal‐impregnated TiO2 catalysts such as Fe, Co, Ni, and Cu. Various techniques, such as thermogravimetric analysis (TGA), UV–Vis, X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and X‐ray fluorescence (XRF) were used to characterize these catalysts. The operational parameters for the photocatalytic degradation process were chosen as solution pH, catalyst dose, and metal impregnation percentage (imp%), and they were optimized using response surface methodology (RSM). pH was found as an important factor, and its impact on the photocatalytic degradation efficiency was more significant than the other operational parameters. The average degradation efficiency of the compounds reached 93.1% for Fe‐TiO2, 92.08% for Co‐TiO2, 89.09% for Ni‐TiO2, 88.81% for Cu‐TiO2, and 86.3% for TiO2 at the optimum conditions.