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Veröffentlichung The fate of nitrification and urease inhibitors in simulated bank filtration(2023) Förster, Christina; Scheurer, Marco; Klitzke, Sondra; Ruhl, Aki Sebastian; Zeeshan, MuhammadThe application of nitrification and urease inhibitors (NUI) in conjunction with nitrogen (N) fertilizers improves the efficiency of N fertilizers. However, NUI are frequently found in surface waters through leaching or surface runoff. Bank filtration (BF) is considered as a low-cost water treatment system providing high quality water by efficiently removing large amounts of organic micropollutants from surface water. The fate of NUI in managed aquifer recharge systems such as BF is poorly known. The aim of this work was to investigate sorption and degradation of NUI in simulated BF under near-natural conditions. Besides, the effect of NUI on the microbial biomass of slowly growing microorganisms and the role of microbial biomass on NUI removal was investigated. Duplicate sand columns (length 1.7 m) fed with surface water were spiked with a pulse consisting of four nitrification (1,2,4-triazole, dicyanodiamide, 3,4-dimethylpyrazole and 3-methylpyrazole) and two urease inhibitors (n-butyl-thiophosphoric acid triamide and n-(2-nitrophenyl) phosphoric triamide). The average spiking concentration of each NUI was 5 ÎÌg/L. Experimental and modeled breakthrough curves of NUI indicated no retardation for any of the inhibitors. Therefore, biodegradation was identified as the main elimination pathway for all substances and was highest in zones of high microbial biomass. Removal of 1,2,4-triazole was 50% and n-butyl-thiophosphoric acid triamide proved to be highly degradable and was completely removed after a hydraulic retention time (HRT) of 24 h. 50% of the mass recovery for nitrification inhibitors except for 3,4-dimethylpyrazole was observed at the effluent (4 days HRT). In addition, a mild effect of NUI on microbial biomass was noted. This study highlights that the degradation of NUI in BF depends on HRT and microbial biomass. © 2023 ElsevierVeröffentlichung Levels and temporal trends of Trifluoroacetate (TFA) in archived plants: evidence for increasing emissions of gaseous TFA precursors over the last decades(2022) Freeling, Finnian; Scheurer, Marco; Hoffmann, Gabriele; Koschorreck, JanTrifluoroacetate (TFA) is a highly mobile and persistent compound that occurs ubiquitously in the environment. Results from previous studies suggested an increase in the atmospheric deposition of TFA in the Northern Hemisphere starting in the 1990s. Due to its physicochemical properties, TFA can be efficiently taken up and accumulated by vascular plants. Consequently, plants could serve as a biomonitoring tool to evaluate the presence of TFA in the terrestrial environment. This is the first study which describes the concentrations and temporal trends of TFA in biota by analyzing archived leaf samples of various tree species from the German Environmental Specimen Bank (observation period: 1989-2020). Samples from different locations of the same species were each in a similar concentration range. The highest concentrations (up to ca. 1000 mikrog/kg dry weight) were found in Lombardy poplar (Populus nigra "Italica") leaves. A statistically significant positive trend in the TFA concentration within the study period was found for most species/sites, which is likely the result of both bioaccumulation as well as increasing emissions of gaseous TFA precursors over the last three decades. These results contribute to the current discussion on the regulation of per- and polyfluoroalkyl substances (PFAS) to protect human and environmental health. Quelle: www.pubs.acs.org