Degradation of the mixture of the ketoprofen, meloxicam and tenoxicam drugs using TiO2/metal photocatalysers supported in polystyrene packaging waste

Abstract

The solution mixture of the non-steroidal anti-inflammatory drugs ketoprofen, meloxicam and tenoxicam was degraded through systems, composed of different photocatalysts based on TiO2 (Fe and Cu) and the hydrogen peroxide oxidant. The monitoring was performed by UV-Vis spectroscopy. Under sunlight radiation, a reduction in peaks was observed with the use of impregnated photocatalysts. After 60 min, the sun/H2O2/Fe-TiO2 system reached degradations of 46.5% and 93.2% at 260 and 367 nm, respectively, and was selected for further studies. The degradation kinetic reached 92 and 96% of degradation after 180 min, for the λ of 260 and 367 nm, respectively. The kinetic curve could be represented by the empirical model proposed by Nichela and co-authors, indicating that besides the heterogeneous photocatalysis that occurs at the surface of the TiO2 there is also the joint effect of the photo-Fenton process. After the treatment, there was no toxicity to cress and lettuce seeds. However, a sensitivity of the thyme seeds to the compounds formed during the treatment was verified. After the fifth treatment cycle, the supported photocatalyst showed degradation higher than 82%. These results indicate that this system is suitable for the treatment of effluents containing pharmaceutical compounds.

Conversion of Plastic Waste into Supports for Nanostructured Heterogeneous Catalysts: Application in Environmental Remediation

“…Furthermore, the efficiency of reuse of the photocatalyst was also evaluated, and after the fifth treatment cycle, the supported photocatalyst still showed degradation greater than 82%. These results indicate that this photocatalytic system is suitable for the treatment of effluents containing pharmaceutical compounds [21].…”

“…Plastic waste has been extensively investigated to obtain new value-added products, such as composites applied in various industrial sectors, and for the development of technologies applied in environmental decontamination, such as supports for nanostructured catalysts. These nanostructured materials are of high importance in several catalytic applications, but their use in suspension can cause reaction problems and risks to the environment [19][20][21].…”

“…Moura et al (2021) [21] used polystyrene residues from post-consumer yogurt packaging to manufacture films for the immobilization of TiO 2 impregnated with copper and iron for application in photocatalytic systems in the degradation of the drugs ketoprofen, tenoxicam and meloxicam. The results showed that the photodegradation kinetic rates reached values above 92% after 180 min of reaction.…”

“…In this context, plastic waste has been promising for the field of catalysis, in obtaining supports for catalysts, and especially for nanostructured catalysts [19][20][21]. Usually, catalysts are applied in suspension in the reaction medium in powder form, which can influence problems such as loss of the catalyst; another problem is that when the catalyst is applied in powder form, the recovery is carried out using traditional methods, such as separation, extraction, filtration, vacuum distillation or centrifugation, which are tedious and timeconsuming processes.…”

Recent advancements in the fabrication and photocatalytic applications of graphitic carbon nitride-tungsten oxide nanocomposites

“…9,10 Several projects worldwide are looking for strategies to limit this ecotoxicological risk of pharmaceutical products. 7,11…”