Karlsruhe, Germany
Karlsruhe, Germany

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Burke V.,Carl von Ossietzky University | Richter D.,DVGW Technologiezentrum Wasser | Hass U.,Free University of Berlin | Duennbier U.,Free University of Berlin | And 2 more authors.
Environmental Earth Sciences | Year: 2014

The biodegradation of various wastewater-derived organic trace pollutants occurring in different aquatic compartments of the environment was previously reported to be influenced by the prevailing redox conditions. However, comparative studies on the redox-dependent degradation behavior of organic trace pollutants are scarce. The objective of the study presented herein, was to compile and evaluate data from several comparable previous tank experiments, thus, providing an overview on the redox-dependent removal of a total of 27 wastewater-derived trace compounds, including phenazone type compounds, antimicrobials, ß-blockers, psychoactive drugs and sulfonamides. Removal rate constants were fitted assuming first-order degradation kinetics. Six compounds were identified to be removed solely under oxic, three compounds solely under anoxic conditions. Others persisted under all experimental conditions, while some were removed under both oxic and anoxic conditions. © 2013 Springer-Verlag Berlin Heidelberg.


Wagner M.,DVGW Technologiezentrum Wasser | Schmidt W.,DVGW Technologiezentrum Wasser | Imhof L.,DVGW Technologiezentrum Wasser | Grubel A.,A.p.f. Aqua System AG | And 3 more authors.
Water Research | Year: 2016

In this article, two methods for in-depth analysis of humic substances fluorescence are presented. The first one allows the combined analysis of fluorescence excitation-emission matrix (EEM) with chromatography technique. The main issue is the coupling of size exclusion chromatography (SEC) with spectroscopy by the use of an absorption and a fluorescence spectrometer as additional detectors. These allow a detailed characterization of humic substances depending on their molecular size, concentration and optical properties. For the evaluation of the resulting complex data, a model based on non-negative matrix factorization, which is also presented in this article, was developed. From the results of the examined humic substances standards, the second method was developed. It allows the characterization and quantification of humic substances fluorescence of a natural water sample solely on the basis of an excitation-emission matrix. The validation of the model is carried out within the framework of extensive analysis of real water samples. © 2016 Elsevier Ltd.


PubMed | a.p.f. Aqua System AG and DVGW Technologiezentrum Wasser
Type: | Journal: Water research | Year: 2016

In this article, two methods for in-depth analysis of humic substances fluorescence are presented. The first one allows the combined analysis of fluorescence excitation-emission matrix (EEM) with chromatography technique. The main issue is the coupling of size exclusion chromatography (SEC) with spectroscopy by the use of an absorption and a fluorescence spectrometer as additional detectors. These allow a detailed characterization of humic substances depending on their molecular size, concentration and optical properties. For the evaluation of the resulting complex data, a model based on non-negative matrix factorization, which is also presented in this article, was developed. From the results of the examined humic substances standards, the second method was developed. It allows the characterization and quantification of humic substances fluorescence of a natural water sample solely on the basis of an excitation-emission matrix. The validation of the model is carried out within the framework of extensive analysis of real water samples.


Leusch F.D.L.,Global Water Research Coalition | Leusch F.D.L.,Griffith University | De Jager C.,University of Pretoria | Levi Y.,University Paris - Sud | And 6 more authors.
Environmental Science and Technology | Year: 2010

Bioassays are well established in the pharmaceutical industry and single compound analysis, but there is still uncertainty about their usefulness in environmental monitoring. We compared the responses of five bioassays designed to measure estrogenic activity (the yeast estrogen screen, ER-CALUX, MELN, T47D-KBluc, and E-SCREEN assays) and chemical analysis on extracts from four different water sources (groundwater, raw sewage, treated sewage, and river water). All five bioassays displayed similar trends and there was good agreement with analytical chemistry results. The data from the ER-CALUX and E-SCREEN bioassays were robust and predictable, and well-correlated with predictions from chemical analysis. The T47D-KBluc appeared likewise promising, but with a more limited sample size it was less compelling. The YES assay was less sensitive than the other assays by an order of magnitude, which resulted in a larger number of nondetects. The MELN assay was less predictable, although the possibility that this was due to laboratory-specific difficulties cannot be discounted. With standardized bioassay data analysis and consistency of operating protocols, bioanalytical tools are a promising advance in the development of a tiered approach to environmental water quality monitoring. © 2010 American Chemical Society.


Sperfeld P.,Physikalisch - Technische Bundesanstalt | Barton B.,Physikalisch - Technische Bundesanstalt | Pape S.,Physikalisch - Technische Bundesanstalt | Towara A.-L.,Physikalisch - Technische Bundesanstalt | And 2 more authors.
Metrologia | Year: 2014

In a joint project, sglux and PTB investigated and developed methods and equipment to measure the spectral and weighted irradiance of high-efficiency UV-C emitters used in water disinfection plants. A calibration facility was set up to calibrate the microbicidal irradiance responsivity of actinic radiometers with respect to the weighted spectral irradiance of specially selected low-pressure mercury and medium-pressure mercury UV lamps. To verify the calibration method and to perform on-site tests, spectral measurements were carried out directly at water disinfection plants in operation. The weighted microbicidal irradiance of the plants was calculated and compared to the measurements of various actinic radiometers. © 2014 BIPM & IOP Publishing Ltd.


Schmidt C.K.,RheinEnergie AG | Raue B.,DVGW Technologiezentrum Wasser | Brauch H.-J.,DVGW Technologiezentrum Wasser | Sacher F.,DVGW Technologiezentrum Wasser
International Journal of Environmental Analytical Chemistry | Year: 2014

A novel analytical method for the trace-level determination of the organic phosphonates 1-hydroxyethane(1,1-diphosphonic acid) (HEDP), nitrilotris(methylene phosphonic acid) (NTMP), ethylenediaminetetra(methylene phosphonic acid) (EDTMP), hexamethylenediaminetetra(methylene phosphonic acid) (HDTMP) and diethylenetriaminepenta(methylene phosphonic acid) (DTPMP) in natural waters is described. Key-elements of the novel method are the destruction of the various metal complexes which are present in natural water samples by a strong cation exchange resin, the subsequent 50-fold pre-concentration of the analytes by a weak anion exchanger and their final determination by ion chromatography and inductively coupled plasma mass spectrometry. Addition of the complexing agent diethylenetriaminepentaacetic acid (DTPA) to the eluent of the anion exchanger leads to a significant improvement of the chromatographic performance for all phosphonates, but especially for EDTMP. Detection of the phosphorous species in ICP-MS is done via the molecular ion 47PO+ which exhibits high sensitivity and which is only marginally affected by interferences. Validation of the method gives excellent performance parameters with recoveries close to 100%, limits of detection below 0.1 μg/L for each individual target compound and standard deviations for replicate analyses below 10%. Application of the novel method to environmental samples shows that trace amounts of HEDP and DTPMP may be found in river waters affected by discharges of municipal or industrial wastewater treatment plants. © 2013 © 2013 Taylor & Francis.


Richardt S.,DVGW Technologiezentrum Wasser | Korth A.,DVGW Technologiezentrum Wasser
Integrating Water Systems - Proceedings of the 10th International on Computing and Control for the Water Industry, CCWI 2009 | Year: 2010

To avoid discoloration events in water distribution networks a model for the calculation of optimized flushing intervals has been developed. The model is based on the network specific deposit situation as well as the hydraulic situation in the investigated network area and simulates the deposit growth in each pipe segment with consideration the mobilization. Together with the algorithm for the determination of the data base for the calculation, the model allows highly efficient network maintenance, which leads to a distinct reduction in customer complaints. The model was transferred in a self-running program that can be linked to any hydraulic simulation software. This enables a wide use of the research results under varying conditions. © 2010 Taylor & Francis Group, London.


PubMed | Griffith University, DVGW Technologiezentrum Wasser, KWR Watercycle Research Institute and Research & Innovation
Type: | Journal: Environment international | Year: 2016

The presence of endocrine disrupting chemicals in the aquatic environment poses a risk for ecosystem health. Consequently there is a need for sensitive tools, such as in vitro bioassays, to monitor endocrine activity in environmental waters. The aim of the current study was to assess whether current in vitro bioassays are suitable to detect endocrine activity in a range of water types. The reviewed assays included androgenic (n=11), progestagenic (n=6), glucocorticoid (n=5), thyroid (n=5) and estrogenic (n=8) activity in both agonist and antagonist mode. Existing in vitro bioassay data were re-evaluated to determine assay sensitivity, with the calculated method detection limit compared with measured hormonal activity in treated wastewater, surface water and drinking water to quantify whether the studied assays were sufficiently sensitive for environmental samples. With typical sample enrichment, current in vitro bioassays are sufficiently sensitive to detect androgenic activity in treated wastewater and surface water, with anti-androgenic activity able to be detected in most environmental waters. Similarly, with sufficient enrichment, the studied mammalian assays are able to detect estrogenic activity even in drinking water samples. Fewer studies have focused on progestagenic and glucocorticoid activity, but some of the reviewed bioassays are suitable for detecting activity in treated wastewater and surface water. Even less is known about (anti)thyroid activity, but the available data suggests that the more sensitive reviewed bioassays are still unlikely to detect this type of activity in environmental waters. The findings of this review can help provide guidance on in vitro bioassay selection and required sample enrichment for optimised detection of endocrine activity in environmental waters.


PubMed | DVGW Technologiezentrum Wasser
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2012

This study examines mechanisms for removal of bacteriophages (MS2 and phiX174) by ceramic membranes without application of flocculants. The ceramic membranes considered included ultra- and microfiltration membranes of different materials. Phages were spiked into the feed water in pilot scale tests in a waterworks. The membranes with pore sizes of 10 nm provided a 2.5-4.0 log removal of the phages. For pore sizes of 50 nm, the log removal dropped to 0.96-1.8. The membrane with a pore size of 200 nm did not remove phages. So, the removal of both MS2- and phiX174-phages depended on the pore size of the membranes. But apart from pore size also other factors influence the removal of phages. Removal was 0.5-0.9 log higher for MS2-phages compared with phiX174-phages. Size exclusion seems to be the major but not the only mechanism which influences the efficiency of phage removal by ceramic membranes.


PubMed | DVGW Technologiezentrum Wasser
Type: Journal Article | Journal: Water science and technology : a journal of the International Association on Water Pollution Research | Year: 2012

To determine the removal efficiency of ultrafiltration (UF) membranes for nano-particles in the size range of viruses the state of the art uses challenge tests with virus-spiked water. This work focuses on bench-scale and semi-technical scale experiments. Different experimental parameters influencing the removal efficiency of the tested UF membrane modules were analyzed and evaluated for bench- and semi-technical scale experiments. Organic matter in the water matrix highly influenced the removal of the tested bacteriophages MS2 and phiX174. Less membrane fouling (low TMP) led to a reduced phage reduction. Increased flux positively affected phage removal in natural waters. The tested bacteriophages MS2 and phiX174 revealed different removal properties. MS2, which is widely used as a model organism to determine virus removal efficiencies of membranes, mostly showed a better removal than phiX174 for the natural water qualities tested. It seems that MS2 is possibly a less conservative surrogate for human enteric virus removal than phiX174. In bench-scale experiments log removal values (LRV) for MS2 of 2.5-6.0 and of 2.5-4.5 for phiX174 were obtained for the examined range of parameters. Phage removal obtained with differently fabricated semi-technical modules was quite variable for comparable parameter settings, indicating that module fabrication can lead to differing results. Potting temperature and module size were identified as influencing factors. In conclusion, careful attention has to be paid to the choice of experimental settings and module potting when using bench-scale or semi-technical scale experiments for UF membrane challenge tests.

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