Environmental Fate of Pharmaceuticals in Water/Sediment Systems

Abstract

In recent years there has been growing interest on the occurrence and the fate of pharmaceuticals in the aquatic environment. Nevertheless, few data are available covering the fate of the pharmaceuticals in the water/sediment compartment. In this study, the environmental fate of 10 selected pharmaceuticals and pharmaceutical metabolites was investigated in water/sediment systems including both the analysis of water and sediment. The experiments covered the application of four 14C-labeled pharmaceuticals (diazepam, ibuprofen, iopromide, and paracetamol) for which radio-TLC analysis was used as well as six nonlabeled compounds (carbamazepine, clofibric acid, 10,11-dihydro-10,11-dihydroxycarbamazepine, 2-hydroxyibuprofen, ivermectin, and oxazepam), which were analyzed via LC-tandem MS. Ibuprofen, 2-hydroxyibuprofen, and paracetamol displayed a low persistence with DT50 values in the water/sediment system < or =20 d. The sediment played a key role in the elimination of paracetamol due to the rapid and extensive formation of bound residues. A moderate persistence was found for ivermectin and oxazepam with DT50 values of 15 and 54 d, respectively. Lopromide, for which no corresponding DT50 values could be calculated, also exhibited a moderate persistence and was transformed into at least four transformation products. For diazepam, carbamazepine, 10,11-dihydro-10,11-dihydroxycarbamazepine, and clofibric acid, system DT90 values of >365 d were found, which exhibit their high persistence in the water/sediment system. An elevated level of sorption onto the sediment was observed for ivermectin, diazepam, oxazepam, and carbamazepine. Respective Koc values calculated from the experimental data ranged from 1172 L x kg(-1) for ivermectin down to 83 L x kg(-1) for carbamazepine.

First-Order Contaminant Removal in the Hyporheic Zone of Streams: Physical Insights from a Simple Analytical Model

“…The first-order rate constant corresponds to a contaminant half-life of 1.6 days, which is typical for the respiration of dissolved organic carbon in a stream 9 or the mineralization of a low persistence anthropogenic contaminant, such as the pharmaceutical compound paracetamol, in a sediment/water matrix under environmentally relevant conditions. 19 Contaminant concentrations predicted by the numerical simulation vary dramatically across the upwelling and downwelling zones of the bed form (Figure 2A). In the downwelling (high pressure) zone, contaminant-rich water penetrates approximately half a dune wavelength into the sediment (y ̅ ≈ − π).…”

Impacts of compound properties and sediment characteristics on the sorption behaviour of pharmaceuticals in aquatic systems

“…While research into the sorption of pharmaceuticals in water-sediment systems has recently increased [13,20,27,[33][34][35][36] data are still only available for a few active ingredients so our understanding of the factors and processes affecting sorption of pharmaceuticals is limited. A number of studies have also proposed predictive models for estimating the sorption behaviour of pharmaceuticals in sewage sludge and soil [37,38].…”

SALDI-MS Signal enhancement using oxidized graphitized carbon black nanoparticles

“…The occurrence of pharmaceuticals in the environment is well documented [19], although little is known about their environmental fate and availability [20] or their uptake, possible accumulation, and effects in biota [21]. The determination of the human pharmaceutical propranolol in Baltic Sea blue mussels (Mytilus edulus), exposed to the drug as part of a sublethal chronic exposure experiment, was chosen for an evaluation of the performance of quantitative SALDI analysis.…”