Naslov
DESIGN OF EXPERIMENTS FOR PHOTOLYTIC AND PHOTOCATALYTIC DEGRADATION OF 5 PHARMACEUTICALS IN WATER

Autori
Bertagna Silva, Danilo ; Buttiglieri, Gianluigi ; Babić, Bruna ; Smoljanić, Goran ; Ašperger, Danijela ; Babić, Sandra

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, prošireni sažetak, znanstveni

Izvornik
Book of abstracts of 27th Croatian Meeting of Chemists and Chemical Engineers / Marković, Dean ; Meštrović, Ernest ; Namjesnik, Danijel ; Tomašić, Vesna - Zagreb : Hrvatsko kemijsko društvo, 2021, 71-72

Skup
27th Croatian Meeting of Chemists and Chemical Engineers

Mjesto i datum
Veli Lošinj, Hrvatska, 05.10.2021. - 08.10.2021

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
pharmaceuticals ; photolysis ; photocatalysis ; design of experiments

Sažetak
Pharmaceuticals and their degradation by-products are ubiquitous in water bodies, particularly in the effluent of wastewater treatment plants, but also in the environment. Studies show that, even in small quantities, these substances can cause adverse acute and chronic effects in aquatic life and humans. A great number of works have been investigating parameters which influence kinetic rates of pollutant degradation using UV-LEDs but there is a lack of literature evaluating proper photoreactor design and its impact on reaction rates. In this study, a full factorial Design of Experiments (DoE) approach was used to investigate the simultaneous degradation of 5 different pharmaceuticals in water by photolysis and photocatalysis. An initial solution containing 2 mg/L of each compound (ciprofloxacin, trimethoprim, sulfamethoxazole, venlafaxine hydrochloride, and desvenlafaxine) was illuminated with a lab-scale UV-LED photoreactor (150 mL) for 1 hour. The significance of 4 independent categorical variables (table 1) and their combined effect on each compound’s rate of degradation and the effluent Total Organic Carbon (TOC) and toxicity by Vibrio fischeri was analysed. The results show that every compound was degraded differently in each of the treatments. Anyway, the effect BC (combining the LED wavelength and catalyst presence) was relevant to all of them. The degradation was enhanced either with UVA in the presence of the catalyst or with UVC in the absence of the catalyst. This can be explained by the light screening effect of the catalyst [3], which hinders the photolytic degradation route when UVC is used. For longer wavelengths, in the case of UVA, the screening effect was smaller. Additionally, only ciprofloxacin was degraded by UVA photolysis alone, so the radical production routes created by the catalyst led to a faster degradation. The matrix factor (A in table 1) was the most prominent regarding TOC abatement. This highlights the importance of adequate pretreatments to optimize light-based processes and avoid light screening and radical scavenging related to the effluent matrix and content. The Vibrio fischeri toxicity evaluation showed that lower wavelengths (UVC) helped reducing the toxicity of the initial solution, but attention should be payed to the fact that experiments with UVA generally increased the toxicity levels. This can be explained by the formation of degradation by-products. Many reports in the literature concerning the chosen pharmaceuticals, in fact, call the attention to the formation of toxic substances after the treatment.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo

POVEZANOST RADA