Carbamazepine Degradation by Photolysis and Titanium Dioxide Photocatalysis

Abstract

We investigated the degradation of carbamazepine by photolysis/ultraviolet (UV)-C only and titanium dioxide photocataiysis. The degradation of carbamazepine by UV-only and titanium-dioxideonly (adsorption) reactions were inefficient, however, complete degradation of carbamazepine was observed by titanium dioxide photocataiysis within 30 min. The rate of degradation increased as initial carbamazepine concentration decreased, and the removal i<inetics fit well with the Langmuir-Hinshelwood model. The addition of methanol, a radical scavenger, decreased carbamazepine removal, suggesting that the hydroxide radical played an important role during carbamazepine degradation. The addition of oxygen during titanium dioxide photocatalysis accelerated hydroxide radical production, thus improving mineralization activity. The photocatalytic degradation was more efficient at a higher pH, whereas the removal of carbamazepine and acridine (a major intermediate) were more efficient under aerobic conditions. The mineralization of carbamazepine during photocataiysis produced various ionic by-products such as ammonium and nitrate by way of nitrogen dioxide. Water Environ. Res., 84, 554 (2012).

TiO2 (Core)/Crumpled Graphene Oxide (Shell) Nanocomposites Show Enhanced Photodegradation of Carbamazepine

“…TiGC kinetics are relatively constant over the range of CBZ concentrations (with 10–15% deviation in the reaction constant), whereas the decomposition rate constant of TiO 2 decreases with an increasing CBZ concentration (more than 80% reduction in the reaction constant). A similar observation was reported by others: a higher CBZ initial concentration suppressed the TiO 2 rate of degradation [ 18 , 52 ]. Im et al proposed that, in a TiO 2 colloidal suspension, excess CBZ molecules accumulate on the TiO 2 surface, suppressing the light absorbance and ROS generation by TiO 2 [ 18 ].…”

“…TiO 2 is a widely used heterogeneous and wide bandgap photocatalyst that shows a robust performance and has a low cost. Various studies report the photocatalytic degradation of CBZ by reactive oxygen species (ROS) generated by TiO 2 under UV radiation [ 18 , 19 , 20 ]. However, the influence of environmental factors, such as the presence of natural organic macromolecules (NOM), is often overlooked in evaluating the performance of novel nanomaterials for contaminant removal applications in water.…”

Photocatalytic decontamination of pharmaceutical effluent in a double tube reactor by ZnO catalyst. Physico chemical characterization and optimization.&nbsp;

“…S et al, 2009). At pH values more acidic than PZC (Im. J.K et al, 2012), the ZnO particle will be positively charged and attraction will be enhanced for anionic molecules.…”

Role of thermal decomposition process in the photocatalytic or photoluminescence properties of BiPO4 polymorphs

“…In the case of solid solutions (Bakiz et al, 2018; Hallaoui et al, 2016; Taoufyq et al, 2015), the chemical substitution allowed modifying the energies and intensities of photoluminescence emissions, acting as structural defects, mainly oxygen vacancies.Other authors have shown the role of charge separation or the polarization on photocatalytic activity and photoluminescence emissions (Chen, Huang, Guo, Zhang, & Ma, 2019; Chen et al, 2018; Hao et al, 2019; Huang et al, 2017). Other compounds such as TiO 2 (Im, Son, Kang, & Zoh, 2012), ZnO (Tanveer, Guyer, & Abbas, 2019), Bi 2 MoO 6 (Bi et al, 2007), BaSO 4 (Cui et al, 2019), Ag 3 PO 4 (Ge, 2014), Na 3 Bi 2 (PO 4 ) 3 (Huang, Chen, & Zhang, 2014), Zn 3 (PO 4 ) 2 (Naciri et al, 2018), Mn 3 (PO 4 ) 2 (Bouddouch et al, 2019), and BiVO 4 (Zhou et al, 2006)were also studied. Recently, we have developed studies on phosphate‐based phases for electrocatalytic applications (Chennah, Naciri, Ahsaine, et al, 2018; Chennah, Naciri, Taoufyq, et al, 2018; Ghalwa & Zaggout, 2006).…”