1. Ozonation of amoxicillin and ciprofloxacin in model hospital wastewater to increase biotreatabilitySeverina Aleksić, Andreja Žgajnar Gotvajn, Katarina Premzl, Mitja Kolar, Sonja Šostar-Turk, 2021, original scientific article Abstract: Amoxicillin (AMX) and Ciprofloxacin (CIP) are antibiotics commonly used in human medicine with high environmental toxicity and poor biodegradability. They have been found in various hospital effluents and groundwater, and their environmental impact is still not fully understood. In this work, we investigated the possibility of treating model wastewaters containing the antibiotics AMX and CIP using ozonation, with the addition of H$_2$O$_2$ under various conditions, including different pH values, H$_2$O$_2$, and ozone dosages. The quantification of and treatment efficacy for antibiotic removal were determined via solid phase extraction followed by chromatographic separation by liquid chromatography coupled with tandem triple quadrupole mass spectrometry (LC/MS/MS). This analytical system is quite efficient for the detection of all major antibiotic classes, even if they are present at very low concentrations. The efficiency of ozonation was determined by measuring the TOC (Total Organic Carbon) changes after ozonation of the model wastewater and by measuring the concentration of the two antibiotics. In a sequential activated sludge process of ozone-treated model wastewater, almost complete TOC removal and an overwhelming decrease in antibiotic concentrations (up to 99%) were observed. Ozonation resulted in complete removal of AMX and CIP in less than 30 and 120 min, respectively. The results of this work indicate that ozonation could be a suitable pretreatment method to reduce the toxicity of contaminants (AMX and CIP) and improve the biodegradability of hospital wastewater. Keywords: antibiotics, amoxicillin, AMX, ciprofloxacin, CIP, hospital wastewater, hydrogen peroxide, ozone, sludge, water treatment Published in DKUM: 06.08.2024; Views: 75; Downloads: 14
Link to full text This document has many files! More... |
2. Mechanistic insights of polyphenolic compounds from rosemary bound to their protein targets obtained by molecular dynamics simulations and free-energy calculationsSamo Lešnik, Marko Jukič, Urban Bren, 2023, original scientific article Keywords: rosemary, carnosic acid, carnosol, rosmanol, rosmarinic acid, polyphenols, molecular docking, molecular dynamics simulations, linear interaction energy calculations, water-mediated hydrogen-bonds, HIV-1 protease, K-RAS protein, factor X Published in DKUM: 22.04.2024; Views: 185; Downloads: 26
Full text (2,99 MB) This document has many files! More... |
3. Magnetic field effects on redox potential of reduction and oxidation agentsMojca Božič, Lucija Črepinšek-Lipuš, Vanja Kokol, 2008, original scientific article Abstract: Redox potentials of two reducing (sodium dithionite and glucose) and two oxidizing (hydrogen peroxide and sodium hypochlorite) agents were monitored at various concentrations and at different temperatures for 30-75 minutes after the exposure of their water solutions (glucose and hypochlorite solutions once; sodium dithionite and hydrogen peroxide solutions one, two and/or three-times) to the static magnetic field of flux density of 0.9 V s M-2 . The aim of the investigation was to suggest improvements, i.e., intensification and stability, of the reduction-oxidation ability of selected agents applicable in textile fibre processing, primarily bleaching and vat dyeing. Results of the experiments show that magnetic treatment (of solutions) raises both the reducing ability of glucose and the oxidation ability of hydrogen peroxide and sodium hypochlorite, promising some technological and economical benefits for the textile industry as well as forother fields of chemistry. Keywords: magnetic water treatment, sodium dithionite, glucose, hydrogen peroxide, sodium hypochlorite, redox potential, textile vat processing Published in DKUM: 05.07.2017; Views: 1207; Downloads: 129
Full text (206,88 KB) This document has many files! More... |