AbstractsBiology & Animal Science

Degradation of metoprolol by means of advanced oxidation processes

by Rossmary Violette Romero Olarte

Institution: Universitat de Barcelona
Year: 2015
Keywords: Enginyeria química; Ingeniería química; Chemical engineering; Oxidació; Oxidación; Oxidation; Biodegradació; Biodegradación; Biodegradation; Contaminants; Contaminantes; Pollutants; Metoprolol; Ciències Experimentals i Matemàtiques
Record ID: 1124602
Full text PDF: http://hdl.handle.net/10803/294150


For this study the emerging contaminant ß-blocker Metoprolol (MET) has been selected due that it is a highly prescribed pharmaceutical and it has been detected in waste water treatment plants influents, thus, in natural waters. Several studies, focused on the toxicological potential of Metoprolol, indicate its potential environmental relevance and its recalcitrant nature. To remove MET from water, different Advanced Oxidation Processes (AOPs) were used. MET removal was studied, in different reactors with natural and artificial light, by photolysis, UVC/H2O2, photocatalysis, Fenton, photo-Fenton, bicarbonate-activated hydrogen peroxide (with cobalt or iron) processes. The different set-ups and technologies tested have been compared in order to establish the efficiency of the processes. The experiments were normally carried out with 50 mg/L of initial MET in Milli-Q water, free pH, and 25 ± 5 ºC. Thus, photolysis experiments were done in (solarbox (SB), Compound Parabolic Collector (CPC), Black light blue lamps (BLB) and UVC254 nm (UVC) reactors). The best result obtained was 93.5% of MET removal in UVC reactor after 240 minutes. UVC/H2O2 experiments were carried out in UVC reactor. Different H2O2 concentrations and pH were tested and the maximum removals were MET (98%) and TOC (70.7%) for 125 mg H2O2/L. Photocatalysis was carried in SB and CPC with different TiO2 concentrations (0.05, 0.10 and 0.40 g /L). Experiments were also carried out varying the initial MET concentration (25, 50 and 100 mg/L), pH and the water matrix with 0.4 g TiO2/L in SB or adding 25 and 150 mg/L of H2O2. The best results obtained were a complete MET removal and 45.7% of mineralization in SB and 81.5% of MET degradation and 29.2% of mineralization in CPC. The dark-Fenton experiments were carried out at pH in a reactor of 2 L. Two different concentrations of Fe (II) (2.5 mg/L or 10 mg/L) and H2O2 (25 mg/L or 150 mg/L) were used. To improve the Fenton process, the total Iron (II) concentration was divided in equal parts (5) and added at constant periods of time (12 minutes) during 1 hour. With the highest concentrations of iron and H2O2 the maximum MET conversion was 87.0% and mineralization 15.6%. Photo-Fenton experiments were done at pH 3, and temperature of 14 or 25 ºC in four reactors (BLB, SB, CPC and UVC). Two different concentrations of Fe (II) (2.5 mg/L or 10 mg/L) and H2O2 (25 mg/L or 150 mg/L) were used. With the highest iron and H2O2 concentrations, the best results in MET degradation were observed (BLB: 100% in 7 min; SB: 97.3% in 7 min; CPC: 98.3% in 3 min). The dark- Bicarbonate/hydrogen peroxide experiments were carried out with 5 mg/L of MET in drinking water, pH 6.2, and room temperature in a reactor of 0.5 L. To improve the process, cobalt (II) or iron (II) as catalyzer were added in the batch reactor. A complete MET conversion in 40 minutes was achieved. The efficiency of different AOPs and reactors tested was compared from the ratio between accumulated energy and MET eliminated. The energy is better used…