Paracetamol is an antipyretic analgesic widely used globally. It has been recurrently found in water bodies and is known to elicit toxic effects in aquatic species; however, its potential ability to induce oxidative stress in sentinel species remains unknown The objective was to establish a methodology to evaluate the toxicity elicited on the sentinel species Hyalella azteca by paracetamol-enriched sediment using oxidative stress tests. Concentrations used in assays were determined using the previously obtained median lethal concentration (72 h LC₅₀). The following oxidative stress biomarkers were evaluated: lipid peroxidation (LPO), protein carbonyl content (PCC) in order to determine oxidized protein content, and the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). LPO and PCC increased significantly while SOD, CAT, and GPX decreased significantly (p < 0.05) with respect to controls. Paracetamol induces oxidative stress on H. azteca, and the set of tests employed is helpful in evaluating the toxicity of this group of pharmaceuticals on aquatic species.

PURPOSE: The present research aims to optimize the removal of ibuprofen (IBP), a non-steroidal anti-inflammatory, analgesic, and antipyretic drug from the aqueous solution using a synthesized magnetic carbon–iron nanocomposite, and to investigate the individual and combined effects of the independent process variables. METHOD: Combining the adsorptive capability of carbon and magnetic property of iron, a carbon–iron nanocomposite was synthesized. A four-factor Box–Behnken experimental design-based optimization modeling was performed for maximizing the removal of IBP from water by the nanocomposite using the batch experimental data. A quadratic model was built to predict the responses. Significance of the process variables and their interactions was tested by the analysis of variance and t test statistics. RESULTS: The experimental maximum removals of IBP from the aqueous solution by carbon and magnetic nanocomposite were 14.74% and 60.39%, respectively. The model predicted maximum removal of 65.81% under the optimum conditions of the independent variables (IBP concentration 80 mg/l; temperature 48°C; pH 2.50; dose 0.6 g/l) was very close to the experimental value (65.12 ± 0.92%). pH of the solution exhibited most significant effect on IBP adsorption. CONCLUSION: The developed magnetic nanocomposite was found superior than its precursor carbon exhibiting higher removal of IBP from the water and can be easily separated from the aqueous phase under temporary external magnetic field. The developed magnetic nanocomposite may be used for an efficient removal of IBP from the water.

PURPOSE: Some of the pharmaceuticals that are not extensively investigated in the aquatic environment are the anesthetic lidocaine (LDC), the analgesic tramadol (TRA), and the antidepressant venlafaxine (VEN). LDC metabolizes to 2,6-xylidine (2,6-DMA) and monoethylglycinexylidine (MEGX), TRA to O-desmethyltramadol (ODT), and VEN to O-desmethylvenlafaxine (ODV). Within this study, the distribution and behavior of these compounds in German wastewater treatment plants (WWTPs) were investigated. METHODS: Samples of influents and effluents from WWTPs in Hesse, Germany were collected between January and September 2010. Analytes were extracted from wastewater samples by solid-phase extraction and from solid samples by sonication. Extracts were measured using gas chromatography/mass spectrometry. RESULTS: LDC, TRA, VEN, ODT, and ODV were detected in all analyzed influent and effluent samples. 2,6-DMA could not be identified. MEGX was not detected. TRA and ODV were present in untreated wastewater at the highest concentrations (max, 1,129 (TRA) and 3,302 ng L−1 (ODV)), while the concentrations of LDC and VEN were all significantly lower (mean, 135 (LDC) and 116 ng L−1 (VEN)). All of the analytes were only partially removed in the WWTPs. The mean ratios between the concentrations of the metabolites and their respective parent compounds in influents were 4.7 (ODV/VEN) and 0.7 (ODT/TRA). These values remain approximately constant comparing influents and effluents. CONCLUSIONS: LDC, TRA, VEN, ODT, and ODV are only partially removed from sewage water by WWTPs and thus are continuously discharged in respective recipient rivers. A further transformation of TRA and VEN into the known metabolites during treatment in the WWTPs is not observed.