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Bactericides in the environment: Occurrence of selected bactericides in wastewater and their impact on the aquatic environment
DUŠÁNKOVÁ, Monika
Bactericides are a group of chemically active substances that exhibit antimicrobial effects. Their ability to kill or inhibit the growth of unwanted microorganisms is widely used in industry and healthcare, but also in household. However, the widespread use of bactericides has resulted in the abundant occurrence of these substances in surface water and wastewater, which subsequently supports the development of antibiotic resistance. Specifically wastewater treatment plants (WWTP) significantly influence the entry of antibiotic resistance genes into the environment. This study aimed to determine the occurrence of bactericides in wastewater and surface water samples, sediments and sewage sludge using high-performance liquid chromatography hyphenated with mass spectrometry. The detected concentrations were used to evaluate removal efficiency and impact on the recipient. The positive removal efficiency was confirmed mainly for the group of quaternary ammonium compounds and some antibiotics. Clarithromycin achieved the highest removal efficiency. Although some monitored substances had a high removal efficiency at the WWTP, their final occurrence proved to affect the aquatic environment. Quaternary ammonium compounds were effectively removed from the wastewater. But mainly thanks to their properties, such as strong sorption to solid substances, i.e., sediments and sludge, they were concentrated in sewage sludge. Using sewage sludge on agricultural land can cause problems by retaining some monitored substances in soils or leaching them into the surface and groundwater. This work briefly described the fate of selected bactericides at the sewage treatment plant and the adjacent recipient. The possible risks of using bactericides and their entry into the environment were pointed out. Given the variety and quantity of bactericides and the severe consequences of their excessive use, this topic deserves wider attention.
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Efficiency of the technology of WWTP České Budějovice for the elimination of pharmaceuticals
BARTOŇ, Jiří
The main aim of this study was to investigate the efficiency of wastewater treatment plant (WWTP) in České Budějovice for the elimination of selected pharmaceuticals (carbamazepine, diclofenac, atenolol, metoprolol, sotalol, bisoprolol, valsartan, verapamil and tramadol) over a long time period (March 2011 - February 2012). Time-proportional 24 hours pooled samples of wastewater from influent and effluent of the WWTP were used to assess the efficiency of WWTP. The concentrations of target compounds were determined by using in line SPE/LC-MS/MS analysis. The average annual concentrations in the effluent of WTP were in the range of 0,019 microgram/l (verapamil) to 1,00 microgram/l (atenolol). Average annual efficiencies of pharmaceutical elimination in WWTP based on pooled samples were found in the case of carbamazepine (-22 %), tramadol (-15 %), sotalol (-1 %), diclofenac (15 %), metoprolol (16 %), verapamil (43 %), bisoprolol (48 %) and valsartan (85 %). The statistical analysis of daily results in the winter and in the summer period showed significantly higher efficiency of the WWTP in the summer for 5 target compounds (diclofenac, atenolol, valsartan, sotalol and bisoprolol). Removal efficiency for the rest of pharmaceuticals did not show significant differences. Elevated temperature and longer irradiation period in summer can positively affect biodegradation or increased photolysis respectively.
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