Landeswasserversorgung (Germany)

Reversed-phase liquid chromatography coupled to high-resolution mass spectrometry (RP-LC-HRMS) is the standard for nontarget screening (NTS) of environmental samples but lacks retention of highly polar contaminants. We compared 12 chromatographic methods across four platforms, RP-LC, anion chromatography (IC), supercritical fluid chromatography (SFC), and hydrophilic interaction chromatography (HILIC), using 127 environmentally relevant compounds (logDpH7.4 -5.6 to 6.6). Compounds were analyzed in solvent and for a polar subset, in groundwater enriched by vacuum evaporation. Data were collected across four laboratories using 5 RP-LC-, 3 HILIC-, 2 SFC-, and 2 IC-HRMS setups. Feature detection with standard tools yielded more false negatives for SFC and IC. To enable a fair and method-agnostic comparison, an extracted ion chromatogram (EIC)-based workflow was used. Of the 127 compounds, 125 were detected by at least one platform. For logDpH7.4 > 0, RP-LC covered ∼90%, followed by SFC (∼70%), while IC and HILIC each covered <30%. For very polar compounds (logDpH7.4 < 0), coverage dropped across all platforms. SFC and HILIC detected up to 60% of polar analytes; IC performed better in negative ionization mode, consistent with anion-exchange separation. Detection frequency declined with polarity, reflecting analytical limitations. Combining RP-LC with either SFC or HILIC increased coverage to 94%. In spiked groundwater, coverage was lower (73%) due to matrix effects and losses during vacuum enrichment. Peak widths were narrowest for SFC (∼2.5 s) and RP-LC (∼4 s) and broadest for HILIC (∼7 s) and IC (∼17 s). Retention times showed limited cross-platform correlation while ionization efficiency was consistent, except for SFC. As no single method provided full coverage, combining RP-LC with one complementary platform (SFC, HILIC, or IC) is required to extend chemical space in environmental NTS.

Riverbed clogging compromises the ecological functioning of gravel-bed rivers. Physical clogging affects aquatic habitats and occurs when fine sediments infiltrate coarser substrates, reducing permeability, porosity, and oxygenation. Clogging analyses mostly rely on methods or models that assess the clogging state from field data without predictive capacity. However, predictive tools are essential to optimize habitat restoration in mountain rivers. This study evaluates a two-dimensional numerical model for simulating fine sediment infiltration and mobilization around two large wood pieces in a fully controlled morphodynamic gravel-bed channel. Field data from the morphodynamic channel, collected before and after an artificial flood, were used to calibrate the model and compare its outputs with measured sediment parameters. The model reproduces fine sediment fractions in the surface and subsurface layers, especially in a shallow, high-velocity zone that underwent substantial declogging. In contrast, fine sediment fractions increased in a deeper, slower-flowing zone. Additionally, simulated suspended sediment concentration and fine sediment fraction maps highlight how a swale saturated with fine sediment on the floodplain contributed to increased fine sediment infiltration and clogging downstream. These findings demonstrate that a robust 2d model capturing fine sediment dynamics can effectively identify clogging-prone areas in gravel-bed rivers.

Bisphenol-S (BS) has recently raised public concerns for its adverse effect on the health safety and ecological security. BS concentrations were detected in many water resources, ranging from 10 ng L−1 to 300 μg L−1, so that various purification techniques have been sought to remove BS. This study investigated the performance of ozonation and ferrate oxidation in the degradation of BS since they are both promising oxidants with high redox potential among water treatment chemicals. It was observed that both ozone and ferrate can achieve over 99% of BS concentration reduction and up to 22.5% of DOC reduction for dosing 0.036 mM of either ferrate or ozone. The vibrio fisheri toxicity exhibited a decline in the treated samples after ozonation or ferrate oxidation. According to the mass spectra analyzed, the degradation pathways were proposed and oxidation products (OPs) were identified. BS degradation by ozonation and ferrate oxidation followed a similar route and four common OPs (OP-249; OP-497-a; OP-497-b, and OP-201) were detected. While ferrate treatment produced one more intermediate (OP-217), ozonation did not, which is attributed to the intensified decomposition of BS by ozonation. The major impact of this study is that ferrate treatment is comparable to the ozonation in removing BS, and further research continuing from this study is necessary to explore the BS removal in various waters with more complex matrixes (e.g., high natural organic matter contents), to investigate BS degradation mechanisms in depth, and to conduct pilot-scale and full-scale trials to establish operational database in running ferrate oxidation and/or ozonation for the treatment of BS in practical world.

This study addresses the selectivity of liquid chromatography with tandem mass spectrometry for the analysis of the polar analytes trifluoroacetic acid and sulfamic acid in water samples. Such analytes often lack sufficient retention in standard reversed-phase liquid chromatography and rarely produce mass spectrometry transition products of high diagnostic evidence by collision-induced dissociation. The chromatography based on an extra-dense bonding liquid chromatography column for trifluoroacetic acid and on hydrophilic interaction chromatography for sulfamic acid. This enabled sufficient retention of more than twice the void volume for both analytes. Liquid chromatography coupled to low-resolution mass spectrometry was compared with high-resolution mass spectrometry. The limits of quantification for direct injection analysis were determined to<0.05μg/L for trifluoroacetic acid and<0.5μg/L for sulfamic acid. Correction of matrix effects either by internal standards or the standard addition is strongly recommended as matrix effects may vary strongly. The concentrations determined for trifluoroacetic acid and sulfamic acid for real samples were comparable between low and high-resolution mass spectrometry. However, low-resolution mass spectrometry does not fulfill the identification criteria of the analytes following the European Commission council directive 96/23/EC or the SANTE/11945/2015. Since low-resolution mass spectrometry for these analytes may result in false-positive findings, such findings may be controlled by high-resolution mass spectrometry.

Die statistische Modellierung des baulich-betrieblichen Zustandes der Grundstucksanschlusse stutzt sich auf zwei Stichproben, die die zur Verfugung stehende Datenbasis bilden. Die erste Stichprobe setzt sich aus 673 Anschlussleitungen aus Steinzeug DN 100–200 mm mit einer Gesamtlange von 5600 m zusammen, die oberhalb des Grundwassers funktionieren. Die zweite Stichprobe umfangt 100 Anschlussleitungen ebenfalls aus Steinzeug DN 100–200 mm mit einer Gesamtlange von 800 m, die allerdings im Schwankungsbereich des Grundwassers verlegt sind. Es wird zusatzlich, unabhangig vom Grundwasser, der Einfluss der Grundungstiefe auf den technischen Zustand der Grundstucksanschlusse untersucht.

The paper presents the methodology formulated for determining the critical technical state of operating sewer pipes that is based on statistical-stochastic modeling. It describes the theoretical boundary between the area comprised of pipes that do not show any damage or require only maintenance measures and the area comprised of pipes that require renovation. The study includes concrete collectors with dimensions of DN 600/1100, 800/1200, and 900/1350 mm, stoneware pipes of with diameters ranging from DN 200 mm to 400 mm, and stoneware connections (DN 100-200 mm). The statistical modeling phase was carried out using Weibull distribution, and its parameters were evaluated by the method of moments. In contrast, the stochastic studies were based on a combination of the method of moments and Monte-Carlo mathematical simulations. On the basis of the proposed forecasting, it was possible to carry out a qualitative and quantitative analysis of the technical condition of the exploited sewage systems. Quantitative analysis helped us to determine the necessary range of renovation, which is an important operation component of every linear sewage network.