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Die „Tesla Gigafactory Berlin-Brandenburg“ wird in der 1. Ausbaustufe 1,4 Mio. m3/a Wasser benötigen. Das geklärte Abwasser mitsamt der problematischen Inhaltsstoffe soll in nur schwach durchflossene, intensiv genutzte Berliner Gewässer eingeleitet werden. Wie sind solche Industrieansiedlungen aus Sicht der Gewässerforschung zu bewerten?

The hyporheic zone (HZ) is considered a hydrodynamically-driven bioreactor with significant pollutant removal capacities and can therefore not only improve wholestream water quality but also preserve human and ecosystem health. Microbial metabolism is hypothesized to play a key role in pollutant transformation in hyporheic sediments of natural streams. However, previous work investigating the influence of microbial metabolism on pollutant transformation has been predominantly laboratory studies. The key challenge for field studies is the appropriate determination of net microbial metabolism, i.e. information on the actual exposure times to specific microbial processes in the investigated system. The present study uses reactive fluorescent tracers to determine microbial metabolism and ultimately its influence on pollutant transformation, e.g. for trace organic compounds, in hyporheic sediments under natural conditions. In particular, the reactive fluorescent tracers resazurin and its main transformation product resorufin were used to determine the microbial metabolism of facultative or obligate aerobes. The influence of the derived microbial metabolism on the transformation of 20 trace organic compounds, such as pharmaceuticals, including 3 parent-daughter pairs, was examined. The present findings validate laboratory results on the microbially-mediated transformation of the anticonvulsant gabapentin to its main transformation product gabapentin lactam under natural conditions. All other TrOCs investigated did not show a clear link between TrOC reactivity to the microbial metabolism informed by the resazurin-resorufin-system. Overall, the present study not only demonstrates the use of the fluorescent tracer-system resazurin and resorufin for determining microbial metabolism of facultative or obligate aerobes but also generally highlights the potential of reactive fluorescent tracers to disentangle specific reactive properties and ultimately their influence on the fate of pollutants in natural HZs.

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Attenuation of trace organic compounds (TrOCs) in a river occurs to a large extent in its hyporheic zone. A major part of the attenuation of polar TrOCs is of microbial origin. As microbial activity depends on temperature and redox conditions, seasonal differences in TrOC attenuation are likely. We investigated TrOC attenuation at a river influenced by treated wastewater during two sampling campaigns, one in summer and one in winter. In addition to redox conditions and temperature, we also determined residence times of porewater in sediment using three methods: (a) non‐parametric deconvolution of electrical conductivity time series, (b) the model VFLUX 2.0 based on temperature time series (only summer), and (c) applying Darcy's law to differences in hydraulic heads (only summer). Contrary to our expectations, we found higher attenuation for 12 out of 18 TrOCs in winter, while three TrOCs were better attenuated in summer. Sediment conditions varied between seasons as more of the top sandy layer with a higher hydraulic permeability accumulated on the river bed in summer. As a result, residence times in the sediment were shorter in summer. In winter, longer residence times, lower temperatures, and a steeper oxygen gradient in sediment coincided with higher TrOC attenuation. Further research is needed to understand our unexpected findings and underlying mechanisms., Key Points: The attenuation of 12 out of 18 trace organic compounds (TrOCs) in the hyporheic zone was higher in winter while three TrOCs were attenuated better in summer. Residence times in sediment were longer and more diverse in winter. The extent of the oxic sediment was similar between seasons but the gradient from the oxic to anoxic zone was steeper in winter., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, EC | H2020 | H2020 Priority Excellent Science | H2020 Marie Skłodowska‐Curie Actions (MSCA) http://dx.doi.org/10.13039/100010665, University of Western Australia ‐ University Postgraduate Award, Australian Government Research Training Program Scholarship, Bundesministerium für Bildung und Forschung (BMBF) http://dx.doi.org/10.13039/501100002347, https://doi.org/10.18728/igb-fred-578.0

Introduction Mammography is the gold standard for early breast cancer detection, but shows important limitations. Blood-based approaches on basis of cell-free DNA (cfDNA) provide minimally invasive screening tools to characterize epigenetic alterations of tumor suppressor genes and could serve as a liquid biopsy, complementing mammography. Methods Potential biomarkers were identified from The Cancer Genome Atlas (TCGA), using HumanMethylation450-BeadChip data. Promoter methylation status was evaluated quantitatively by pyrosequencing in a serum test cohort (n = 103), a serum validation cohort (n = 368) and a plasma cohort (n = 125). Results SPAG6, NKX2-6 and PER1 were identified as novel biomarker candidates. ITIH5 was included on basis of our previous work. In the serum test cohort, a panel of SPAG6 and ITIH5 showed 63% sensitivity for DCIS and 51% sensitivity for early invasive tumor (pT1, pN0) detection at 80% specificity. The serum validation cohort revealed 50% sensitivity for DCIS detection on basis of NKX2-6 and ITIH5. Furthermore, an inverse correlation between methylation frequency and cfDNA concentration was uncovered. Therefore, markers were tested in a plasma cohort, achieving a 64% sensitivity for breast cancer detection using SPAG6, PER1 and ITIH5. Conclusions Although liquid biopsy remains challenging, a combination of SPAG6, NKX2-6, ITIH5 and PER1 (SNiPER) provides a promising tool for blood-based breast cancer detection.

Trace organic compounds (TrOCs) enter rivers with discharge of treated wastewater. These effluents can contain high loads of dissolved organic matter (DOM). In a 48 h field study, we investigated changes in molecular composition of seven DOM compound classes (FTICR-MS) and attenuation of 17 polar TrOCs in a small urban stream receiving treated wastewater. Correlations between TrOCs and DOM were used to identify simultaneous changes in surface water and the hyporheic zone. Changes in TrOC concentrations in surface water ranged between a decrease of 29.2% for methylbenzotriazole and an increase of 152.2% for the transformation product gabapentin-lactam. In the hyporheic zone, only decreasing TrOC concentrations were observed, ranging from 4.9% for primidone to 93.8% for venlafaxine . TrOC attenuation coincided with a decline of molecular diversity of easily biodegradable DOM compound classes while molecular diversity of poorly biodegradable DOM compound classes increased. This concurrence indicates similar or linked attenuation pathways for biodegradable DOM and TrOCs. Strong correlations between TrOCs and DOM compound classes as well as high attenuation of TrOCs primarily occurred in the hyporheic zone. This suggests high potential for DOM turnover and TrOC mitigation in rivers if hyporheic exchange is sufficient.

Rivers being influenced by treated wastewater are characterized by an altered water chemistry compared to their natural state. Downstream of the outlet of a wastewater treatment plant (WWTP), concentrations of dissolved organic matter (DOM) and trace organic compounds (TrOCs) in the receiving river are increased. As DOM might serve as a metabolic co-substrate during microbial TrOC degradation, DOM influences the attenuation of TrOCs. Due to steep biochemical gradients at the surface water - groundwater interface, the hyporheic zone is considered a hotspot for microbial activity. Therefore, turnover rates in the hyporheic zone of a stream are high in comparison to the turnover rates in the water column. The River Erpe is a sandy lowland river in the East of Berlin, Germany, which receives treated wastewater from the WWTP Muenchehofe. In order to study the simultaneous fate of TrOCs and DOM in surface water and the hyporheic zone, a field sampling campaign was conducted at a side channel of the River Erpe. Surface water samples were taken at site A and both surface and pore water samples from 25 cm sediment depth were taken at site B which is 850 m downstream of site A. The sampling interval was every three hours over 48 hours. Samples were analysed for 17 TrOCs (HPLC-MS/MS) and the molecular composition of DOM (FT-ICR MS). DOM compound classes were calculated semi-quantitatively as the percentage share of each class of the whole DOM composition. Mean concentrations of the TrOCs analysed changed by an increase of 200 % to a decrease of 29 % in the surface water between site A and B and by a decrease of 5 to 93 % in the hyporheic zone at site B. The molecular composition of DOM changed at most by a single digit percentage per compound group with the attenuation being larger in the hyporheic zone. The percentage share of two out of seven DOM compound classes significantly correlated with the concentration of at least ten TrOCs between surface water at site A and B. Such a correlation was observed for five compound classes in the hyporheic zone at site B. The present study shows that the attenuation of both TrOCs and DOM in a sandy urban river mainly takes place in the hyporheic zone but it is not capable of assuming a causal relationship between the attenuation of TrOCs and DOM.

The interactions between streamwater and hyporheic or riparian porewater are tightly linked to the biogeochemical and ecological processes within fluvial ecosystems. The analyses of hyporheic biogeochemical cycles or hyporheic exchange fluxes often involves manual sampling of porewater or measurement of temperature time series in the streambed. Here, we compare these two techniques with electrical conductivity time series from a cluster of small, hyporheic EC sensors and discuss their implications on the interpretation of groundwater – surface-water interactions in a first-order boreal stream.Based on repeated measurements and the co-located small, hyporheic EC sensors, we found that even small sampling-rates of sediment porewater alter the hyporheic flow at some locations significantly. However, since porewater samples are necessary for the analysis of hyporheic biogeochemical cycles and water source partitioning, we recommend for future experiments to either co-locate small, continuous sensors with the sampling ports or to conduct experiments quantifying the induced flux.Calculated 1D fluxes based on profiles of temperature time series are often integrated over many centimetres to a few decimetres, if the sensors spacing is not very small. This might be the reason, why fluxes based on our temperature and EC measurements do not always have the same direction, especially if the fast hyporheic exchange fluxes are very shallow.We conclude, that using several, co-located techniques together can compensate for the limitations of each technique and reduce the risk of misleading conclusions.

Mammography is the gold standard for early breast cancer detection, but shows important limitations. Blood-based approaches on basis of cell-free DNA (cfDNA) provide minimally invasive screening tools to characterize epigenetic alterations of tumor suppressor genes and could serve as a liquid biopsy, complementing mammography.Potential biomarkers were identified from The Cancer Genome Atlas (TCGA), using HumanMethylation450-BeadChip data. Promoter methylation status was evaluated quantitatively by pyrosequencing in a serum test cohort (Although liquid biopsy remains challenging, a combination of

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by multiple scientific disciplines for almost half a century. These previous efforts have shown that the hyporheic zone is a modulator for most metabolic stream processes and serves as a refuge and habitat for a diverse range of aquatic organisms. It also exerts a major control on river water quality by increasing the contact time with reactive environments, which in turn results in retention and transformation of nutrients, trace organic compounds, fine suspended particles, and microplastics, among others. The paper showcases the critical importance of hyporheic zones, both from a scientific and an applied perspective, and their role in ecosystem services to answer the question of the manuscript title. It identifies major research gaps in our understanding of hyporheic processes. In conclusion, we highlight the potential of hyporheic restoration to efficiently manage and reactivate ecosystem functions and services in river corridors. Horizon 2020 Deutsche Forschungsgemeinschaft

The pollution and impairment of stream waters by chemical compounds is one of the threats currently targeted by the enforcement of the EuropeanWater Framework Directive in Denmark. The groundwater/surface water interaction is one the pathways for the release of contaminant in streams. In this study, a 2D advection-dispersion model associated to field measurements was used to investigate the mixing and dilution of pollutants discharging from a groundwater plume to a stream at different times of the year. The model is a continuation of the work by Aisopou et al. (2015) which simulates the mixing of groundwater pollutant plumes seeping into a stream. Extra features such as drains or sewers can also be accounted for as additional point sources in the adapted model presented here, as well as the dilution effect of tributaries to better simulate the possible urbanization of streams. The model was used to characterize a plume of chlorinated compounds that discharges into a small stream at a former industrial site in Raadvad, Denmark (Average stream width: 10 m; average flow: 300 l/s; contaminant mass discharge: ca. 1 kg/y). The simulation was combined with streambed and surface water sampling, as well as monthly flow rate monitoring and groundwater fluxes. The use of the model facilitated the identification of a possible discharge area of the groundwater plume and successfully captured the evolution of the pollutant concentration and mixing. At the time of measurement, the groundwater plume seeped mostly through a narrow area of the streambed, which was confirmed by high concentration results from the streambed water sampling and identification of an upward groundwater flux into the stream. The measurements and simulations carried out at later times of the year revealed the existence of temporal and spatial variations: 1) in the overall quantity of chlorinated compound discharged, 2) in the discharge pathways with additional contribution from a drain, and 3) in the contaminant mixing itself. The results highlight the complexity and variability of the contaminant fluxes at the interface between a groundwater contaminated plume and stream water, and the need for a better understanding of the general dynamics of these fluxes.