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Sonderforschungsbereich 1439 (RESIST)

Degradation und Erholung von Fließgewässerökosystemen unter multiplen Belastungen

Flüsse und Bäche sind Zentren der Biodiversität und für den Menschen lebenswichtig. Durch menschliches Zutun werden Gewässer und ihre Lebensgemeinschaften auf vielfältige Weise beeinträchtigt; mit einem breiten Maßnahmenspektrum wird versucht, diese Beeinträchtigungen wieder rückgängig zu machen. Die Mechanismen, die in Phasen von Degradation und Erholung wirken sind jedoch nur teilweise verstanden, insbesondere, wenn viele Beeinträchtigungen gleichzeitig vorliegen. RESIST untersucht die zu Grunde liegenden Mechanismen durch eine Verbindung von Freilanduntersuchungen und Mesokosmen-Experimenten mit statistischen und mechanistischen Modellierungen und Synthesen. Mit einem breiten Methodenspektrum werden die Effekte multipler Stressoren auf alle Komponenten des Nahrungsnetzes von Fließgewässern (von Viren bis zu Fischen) und auf vier ökosystemare Funktionen untersucht. Der Schwerpunkt der Untersuchungen liegt auf den Effekten dreier weltweit relevanter Stressoren: Temperaturerhöhung, Versalzung und hydromorphologische Degradation sowie der Kombination dieser Belastungsformen. Ziel ist es, die Effekte von Degradation und Erholung auf Biodiversität und Funktionen von Fließgewässern zu verstehen und vorherzusagen.

Neben 15 Forschenden der UDE sind Teams der Universitäten Bochum, Köln, Kiel und Koblenz-Landau sowie des Instituts für Gewässerökologie und Binnenfischerei (Berlin) und des Umweltforschungszentrums Halle-Leipzig am SFB RESIST beteiligt.

Im Projekt der IAC werden Nahrungsnetzanalysen mittels Stabilisotopenanalytik einzelner Aminosäuren in Macrozoobenthos, Fischen und Parasiten im Fokus stehen.

Exkursion zu der Kläranlage Du-Kaßlerfeld (Nur für die Studierende des Bachelor-Studiengangs Water Science)

Mehr...

New Articles Published:

Anam Asghar, Holger V. Lutze, Jochen Tuerk, Torsten C. Schmidt

Influence of water matrix on the degradation of organic micropollutants by ozone based processes: A review on oxidant scavenging mechanism

Journal of Hazardous Materials, Volume 429, 5 May 2022, 128189
https://doi.org/10.1016/j.jhazmat.2021.128189© 2022 Elsevier B.V. All rights reserved.

Vanessa Wirzberger, Valentina I. Merkus, Michelle Klein, Lotta Hohrenk-Danzouma, Holger V. Lutze, Torsten C. Schmidt

Bromide strongly influences the formation of reaction products during the ozonation of diclofenac, metoprolol and isoproturon

Science of The Total Environment, Volume 815, 1 April 2022, 152427
https://doi.org/10.1016/j.scitotenv.2021.152427© 2022 Elsevier B.V. All rights reserved.

Jens Terhalle, Simon E. Nikutta, Dawid L. Krzeciesa, Holger V. Lutze, Maik A. Jochmann, Torsten C. Schmidt

Linking reaction rate constants and isotope fractionation of ozonation reactions using phenols as probes

Water Research, Volume 210, 15 February 2022, 117931
https://doi.org/10.1016/j.watres.2021.117931© 2022 Elsevier B.V. All rights reserved.

Farshid Soleimani, Sina Dobaradaran, Gabriel E. De-la-Torre, Torsten C. Schmidt, Reza Saeedi

Content of toxic components of cigarette, cigarette smoke vs cigarette butts:
A comprehensive systematic review

Science of the Total Environment, Volume 813, 20 March 2022, 152667
https://doi.org/10.1016/j.scitotenv.2021.152667/© 2022 Elsevier B.V. All rights reserved.

Cheolyong Kim, Torsten C. Schmidt, Holger V. Lutze

Oxidation of bromide by heat-activated persulfate – Effects of
temperature and the organic matter surrogate phenol on kinetics
and stoichiometry

Chemical Engineering Journal, Available online 12 November 2021, 133533

https://doi.org/10.1016/j.cej.2021.133533/© 2021 Elsevier B.V. All rights reserved.

Abstract:

Reaction mechanisms of sulfate radical with bromide and organic substances can be largely altered at elevated temperature in heat-activated persulfate process due to different activation energies. This study investigated kinetics and stoichiometry of bromide oxidation in the heat-activated persulfate process. We postulated that reaction of sulfate radical with persulfate, which has relatively low reaction rate (6.3×105 M–1s–1), may become an important reaction at elevated temperatures. Persulfate decomposition was inhibited in the presence of sulfate radical scavenger phenol at low temperature (40℃) whereas phenol affected persulfate decomposition only at < 50°C but not at higher temperatures. This was because the second order reaction rate constant of sulfate radical with persulfate became higher (assumed as 1010 M–1 s–1) than with phenol at temperature > 50°C, which can be explained by a high activation energy (estimated activation energy: 311 kJ·mol–1). Bromate formation was inhibited in the presence of phenol. However, phenol oxidation was not affected by the presence of Br–, even though Br– reacts faster with sulfate radicals than phenol and was present in excess. This indicated that formed reactive bromine species such as Br• and Br2•– oxidize phenol under reformation of bromide. Formation of insoluble products was also observed indicating polymerization of phenol. This can be explained by lack of dissolved oxygen under conditions of heat-activation.

Oliver Höcker, Dirk Flottmann, Torsten C. Schmidt, Christian Neusüß

Non-targeted LC-MS and CE-MS for biomarker discovery in bioreactors:

Influence of separation, mass spectrometry and data processing tools

Science of the Total Environment 798 (2021) 149012

https://doi.org/10.1016/j.scitotenv.2021.149012

0048-9697/© 2021 Elsevier B.V. All rights reserved.

Abstract:

Liquid separation coupled to mass spectrometry is often used for non-targeted analyses in various fields, such asmetabolomics. However, the combination of non-standardized methods, various mass spectrometers (MS) andprocessing tools for data evaluation affect biomarker discovery potentially. Here, we present a comprehensivestudy of these factors based on non-targeted liquid chromatography coupled to time-of-flight (TOF) and Orbitrap MS and capillary zone electrophoresis to Orbitrap analyses of the same bioreactor samples, describing the correlation

of its gas yield with changing feature signal intensity. The three datasets were processed with MZmine 2 and XCMS online and subsequential Partial Least Square Regression (PLSR) with Variable Importance in Projection (VIP) ranking for feature prioritization. The six feature tables were compared to evaluate their overlap of shared features and the influence of the processing software and MS instrument on the VIP values and fold

changes. The overlaps, defined as a fraction of one feature table found in the comparative table, were from 27% to 57% for the comparison of MZmine and XCMS and from 15% to 50% between Orbitrap and TOF data sets, respectively.

Considering the most relevant features only (VIP >1.5), the overlaps were increased significantly in all cases from26% to 95%. For the same data set, both VIP values and fold changeswere well correlated, however, varied significantly between TOF and Orbitrap. CE-MS showed higher total feature numbers compared to LC-MS,

most likely due to its more appropriate selectivity, different sample preparation, and/or the sensitive nano-ESI interface. Since only less than 10% of MS/MS data overlapped, CE-MS provided complementary information to LC-MS. Overall, our systematic study proves the benefits of using different separation techniques and processing tools but also indicates a significant influence of mass spectrometry on comprehensive biomarker discovery.

© 2021 Elsevier B.V. All rights reserved.

Razegheh Akhbarizadeh, Sina Dobaradaran, Gohar Parhizgar, Torsten C. Schmidt, Reza Mallaki

 Potentially toxic elements leachates from cigarette butts into different types of water: A threat for aquatic environments and ecosystems?

Environmental Research 202 (2021) 111706

journal homepage: www.elsevier.com/locate/envres https://doi.org/10.1016/j.envres.2021.111706

Abstract:

 Trillions of cigarette butts (CBs) are released into the environment and the leached potentially toxic elements (PTEs) from CBs may contaminate the environments. In this study, the leaching of PTEs including both heavy metals and metalloids (metal(loid)s) from CBs into deionized water (DW), tap water (TW), and seawater (SW) was checked during the different contact times (from 60 min to 60 days). According to the results, PTEs were leached from CBs into different water samples. However, there were no significant differences between leachates in DW and TW samples (p > 0.05). The results of the distribution coefficient indicated the high tendency of most PTEs to enter the liquid phase. The levels of leached PTEs into DW and TW exceeded the standards of surface freshwater to maintain aquatic life. Although the maximum level of leached metal(loid)s into DW, TW, and SW occurred at different times, for each type of water sample no significant differences were found among the levels of most PTEs at various contact times. Based on the results, the levels of leached metal(loid)s from CBs in seawater peak soon after being released into the water, while for the freshwater, they occur after some days. This phenomenon could possibly have short-term and long-term effects on marine and freshwater organisms, respectively. Due to the ability of the dissolved PTEs to integrate into the aquatic/terrestrial food web and threaten human health, some control measures regarding the disposal of CBs are necessary.

Matin Funck, Mohammed M.S. Al-Azzawi, Aylin Yildirim, Oliver Knoop, Torsten C. Schmidt, Jörg E. Drewes, Jochen Tuerk

 Release of microplastic particles to the aquatic environment via wastewater treatment plants: The impact of sand filters as tertiary treatment

Chemical Engineering Journal 426 (2021) 130933

 https://doi.org/10.1016/j.cej.2021.130933, Elsevier

Abstract:

 Monitoring of microplastics (MP) release into the aquatic environment is an important topic and proposed point sources for microplastics are wastewater treatment plants (WWTPs). Three full-scale WWTPs (A, B, C) were investigated to compare the effect of continuously and discontinuously backwashed sand filters to retain microplastics from secondary treated wastewater effluents. A cascade filtration unit using steel basket filters with mesh sizes of 100 μm, 50 μm and 10 μm was employed for sampling. The subsequent analysis used thermal extraction desorption gas chromatography mass spectrometry (TED-GC–MS). This combined analytical approach offered the benefit of sampling multiple cubic meters of WWTP effluent and using a robust quantification analytical method for microplastic without the need for an additional chemical-based sample preparation step. Due to the different capacities of the three WWTPs, the results were normalized based on population equivalents (P.E.). Four common polymers were targeted in this study (i.e., PE, PS, PP, and PET). PE was the most common polymer detected in secondary effluents, with normalized annual loads ranging between 2.8 mg yr–1P.E.-1 and 8.4 mg yr-1P.E.-1. Results showed that sand filters offered additional efficient MP retention capabilities, with the sand filters offering, on average, an extra 79% ± 11% of MP retention when compared to secondary treatment. Finally, one filter cell with aged and one with restored granular media were compared. The aged cell did not indicate

Sina Dobaradarana, Torsten C. Schmidt, Wiebke Kaziur-Cegla, Maik A. Jochmann

BTEX compounds leachates from cigarette butts into waterenvironment: A primary study

Abstract

Cigarette butts (CBs) are the most abundant types of litter in the environment and may contain toxic chemicals such as BTEX that pose serious risks to the water bodies and health of aquatic organisms. So far there is no systematic study on BTEX compounds (benzene, toluene, ethylbenzene, o-xylene, and p-xylene) leaching from CBs into water environments. In this work, the leaching concentrations of BTEX compounds in deionized water (DW) and river water (RW) samples were studied for the first time. The mean concentrations of benzene, toluene, ethylbenzene, p-xylene, and o-xylene at contact times of 15 min to 1 day in water samples ranged from 0.13 to 0.18, 0.39–0.9, 0.11–0.25, 0.12–0.38, and 0.09–0.19 μgL⁻¹ respectively. Benzene, toluene, ethylbenzene, o-xylene and p-xylene were detected at all contact times in both DW and RW samples. There were no significant differences of the leachate levels of BTEX compounds between DW and RW samples. The highest and lowest mean concentration levels in both DW and RW samples were determined for toluene and o-xylene respectively. The time after smoking had a significant effect on BTEX levels in leachates. The concentration levels of benzene, toluene, ethylbenzene, o-xylene and p-xylene leachates in water samples, after only 15 min, were reduced by 100, 93, 70, 68, and 59 percent respectively. Our data revealed that leached concentrations of benzene did not exceed the Water Framework Directive (WFD) guidelines, but with regard to the amount of CBs littered each year and other toxic chemicals contents of CBs this can still be a threat for aquatic creatures and possibly humans as well. Further studies are needed to cover the knowledge gap on the toxic leachates from CBs into water systems.

Mohaned Hammad, Paolo Fortugno, Sebastian Hardt, Cheolyong Kim, Soma Salamon, Torsten Schmidt, Heiko Wende, Christof Schulz, Hartmut Wiggers
Large-scale synthesis of iron oxide/graphene hybrid materials as highly efficient photo-Fenton catalyst for water remediation
Environmental Technology & Innovation (Free Access till December 31, 2020)

RezaLofti Kahtoonabadi, Maryam Vosough, Lotta Hohrenk, Torsten Schmidt
Employing complementary multivariate methods for a designed nontarget LC-HRMS screening of a wastewater-influenced river
Microchemical Journal, Volume 160, Part A, January 2021, 105641 (Free Access till December 31, 2020)

Collaborative Research Centre (CRC) 1439

Multilevel response to stressor increase and release in stream ecosystems (RESIST)

Rivers and streams are centres of biodiversity and vital to humans. Human activities impair water bodies and their communities in many ways, and a wide range of measures are in place to reverse these stressors. However, the effects of degradation and recovery are only partially understood, especially when many stressors act simultaneously. RESIST investigates the underlying mechanisms by combining field studies and mesocosm experiments with statistical and mechanistic modelling and synthesis. This broad range of methods is used to investigate the effects of multiple stressors on all components of the stream food web (from viruses to fish) and on four ecosystem functions. The focus of the studies is on the effects of three globally relevant stressors: temperature increase, salinization, and hydromorphological degradation, and the combination of these forms of stress. The goal is to understand and predict the effects of degradation and recovery on stream biodiversity and functions.

In addition to 15 researchers from the UDE, teams from the universities of Bochum, Cologne, Kiel and Koblenz-Landau as well as the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (Berlin) and the Helmholtz-Centre for Environmental Research Halle-Leipzig are involved in the CRC RESIST.

Landesregierung bewilligt Projekte

Der FutureWaterCampus kommt

• von Cathrin Becker
• 16.12.2020

Wasser: Weltweit eine wesentliche Ressource – und an der UDE ein Forschungsschwerpunkt. Er wird nun kräftig gestärkt. „Die Bezirksregierung hat die ersten beiden Projekte unseres FutureWaterCampus bewilligt“, freut sich Dr. Michael Eisinger, Geschäftsführer am Zentrum für Wasser- und Umweltforschung (ZWU). Der dazugehörige Forschungsbau wird voraussichtlich im Sommer ebenfalls grünes Licht bekommen. Hier sollen die UDE-Aktivitäten im Bereich der Wasserforschung gebündelt werden.

Der Bewilligung waren zwei Jahre intensiver Arbeit und eine erfolgreiche Prüfung des Projekts vorausgegangen. Die Mühe hat sich gelohnt: Für die Forschung zu innovativen Wassertechnologien stehen jetzt rund 2 Millionen Euro zur Verfügung, Organisation und Management des neuen FutureWaterCampus werden mit 300.000 Euro unterstützt. Das Geld fließt über den Wettbewerb „Forschungsinfrastrukturen NRW“ in das Vorhaben. So will die Landesregierung die regionale Innovationskraft der Wirtschaft stärken und Auf- und Ausbau von Forschungsinfrastrukturen und Kompetenzzentren unterstützen – mit Mitteln des Landes und des Europäischen Fonds für regionale Entwicklung (EFRE).

Ende 2021 soll der Bau des eigenen Forschungszentrums auf dem Essener Thurmfeld beginnen, eröffnet werden soll der FutureWaterCampus 2023. Er wird dynamischer Treffpunkt zahlreicher Expertenteams aus verschiedenen Fachrichtungen sein. Das ZWU-Netzwerk besteht mittlerweile aus über 90 UDE-Forschenden aus 29 Lehrstühlen der Natur- und Ingenieurwissenschaften, der Medizin und der Gesellschaftswissenschaften sowie Wissenschaftler*innen der Universitätsallianz Ruhr und Praxispartnern wie den regionalen Wasserverbänden, so dass viele unterschiedliche Partnerkonstellationen in zukünftigen Projekten denkbar sind“, so Eisinger. Sprecher des Gesamtvorhabens ist Prof. Dr. Torsten C. Schmidt, Vorstandsvorsitzender des ZWU.

Die Beteiligten im ZWU-Netzwerk erforschen gemeinsam, wie der Umgang mit Wasser und Abwasser nachhaltig gestaltet werden kann. Entwickelt werden sollen u.a. gekoppelte Verfahren, Prozesse und Technologien. Dazu zählt auch die geplante Verwendung innovativer technischer Membranen in der Wasserwirtschaft mit weitreichenden Einsatzgebieten.

Weitere Informationen:
Dr. Michael Eisinger, ZWU, Tel. 0201/18 3-3890, michael.eisinger@uni-due.de

Redaktion: Cathrin Becker, Tel. 0203/37 9-1488, cathrin.becker@uni-due.de

ZIM-Projekt wurde zum Erfolgspbeispiel:

Humboldt Stipendiatin am ZWU: Dr. Anam Asghar

New Articles Published:

Preis der Wasserchemischen Gesellschaft
für Dr. Holger Lutze

New Articles Published:

T.H. Uber, T. Hüffer, S. Planitz, T.C. Schmidt
Sorption of non-ionic organic compounds by polystyrene in water
Science of the Total Environment 682(2019), 348-55

Abstract
Polystyrene (PS) is a plastic material that is well known for its use in many different applications, e.g. as shock sensitive packaging.With its prevalence across society, PS contributes significantly to the overall plastic load in aqueous systems. Sorption of organic compounds by the plastics, especiallymicrometer-sized particles, in the environment has become a concern in the past years. The aim of this study was to improve the understanding of sorption properties of PS, one of the major plastic pollutants in the aqueous environment. Batch experiments with PS film (29 μmthickness)were performed for 4 days using a diverse set of 24 sorbates to account for varying molecular properties like polarity or molecular volume. Isotherms were evaluated using different sorption models to elucidate the sorption process of PS. Sorption to PS film was non-linear and absorption into the bulk materialwas the dominant sorption mode. A clear discrimination between the specific and non-specific interactions in the aqueous environment could be shown. The non-linear sorption to PS was shown to be controlled by themolar volume but also by the polarizability/dipolarity parameter (S) of the ppLFER model. The latter is influenced by the aromaticπ-π-interactions of PSwith the sorbate. Similar to other plastics like polyethylene, sorption to PS is driven by hydrophobic interactions but phase descriptors of pristine PS were significantly different than descriptors for other environmental relevant plastics.

S. Dobaradaran, T.C. Schmidt, N. Lorenzo-Parodo, M.A. Jochmann, I. Nabipour, A. Raeisi, N. Stojanovic, M. Mahmoodi
Cigarette butts: An overlooked source of PAHs in the environment?
Environmental Pollution 249 (June 2019), 932-9

Abstract
Cigarette butts (CBs) are the most common littered objects in the environment and may contain high amounts of polycylic aromatic hydrocarbons (PAHs) from incomplete tobacco leave burning. But to date there is no comprehensive study on environmental emissions of PAHs by CBs. So the main aim of this study was to compare the concentration levels of 16 PAHs in freshly smoked CBs and CBs from the environment (collected from urban streets and river areas) with different exposure times to the environment. The results showed that the mean concentration levels of 4 PAHs including naphthalene, acenaphthylene, acenaphthene, and fluorene were significantly higher in the freshly smoked CB samples compared to the street samples and were the lowest in the river samples. Considering the number of CBs annually littered, considerable amounts of these 4 PAHs may be released to the environment, which may be a threat to the quality of water resources.

N.Lorenzo-Parodi, W. Kaziur, N. Stojanovic, M.A. Jochmann, T.C. Schmidt
Solventless microextraction techniques for water analysis
Trends in Analytical Chemistry 113(April 2019), 321-31

Abstract
Microextraction techniques have been proven to provide similar or better results in terms of sensitivity and reproducibility in comparison to liquid-liquid extraction (LLE) and solid-phase extraction (SPE). Furthermore, the high time efficiency and decreased workload leads to a higher sample throughput. In this review the state of the art of some of these techniques, namely solid-phase microextraction (SPME), stir-bar sorptive extraction (SBSE), solid-phase dynamic extraction (SPDE), in-tube extraction-dynamic headspace (ITEX-DHS) and PAL SPME Arrow is shown. Furthermore, their benefits and drawbacks are discussed, together with their applicability to the analysis of water samples. To that end, the latest publications of microextraction techniques for a selection of regulated compound classes (chlorophenols (CPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, short-chained chlorinated paraffins (SCCPs) and volatile organic compounds (VOCs)) are compared. Finally, a guideline for choosing the best microextraction technique for different analytical needs is described.

 

D. Köster, M.A. Jochmann, H.V. Lutze, T.C. Schmidt
Monitoring of the total carbon and nitrogen balance during the mineralization of nitrogen containing compounds by heat activated persulfate
Chemical Engineering Journal (367), 1 July 2019, 160-8

 

​

​
​Abstract
Peroxydisulfate (S₂O₈²⁻) is widely applied in environmental remediation and water treatment as an agent for the unselective oxidation of organic contaminants. S₂O₈²⁻ itself is a strong oxidation agent but activation by heat, UV radiation, or metal catalysts forms sulfate radicals (SO₄⁻), which offer a higher oxidation potential and faster reaction kinetics. The mechanism of degradation for many organic contaminants by sulfate radicals is well studied, but the final mineralization products are not commonly evaluated. Nitrogen containing compounds are known to produce different mineralization products depending on their structure and the reaction conditions. For the identification of the main mineralization products, two approaches for the determination of nitrogen mass balances were evaluated. The first approach was based on a combination of total organic carbon (TOC), and total nitrogen bound (TNb). The second approach used a combination of TOC and ion chromatography (IC). The evaluation based on the TOC and TNb by high temperature combustion was found to be significantly biased as measured ammonium concentrations were underestimated by the TNb measurements in the presence of peroxydisulfate. With the TOC/TNb method, 83.2 ± 1.1% of the initial nitrogen could be recovered after the oxidation. The TOC/IC based approach led to an overall recovery of 91.1 ± 1.4%, where NO₃⁻ and NH₄⁺ were identified as the main products. Based on the fraction of ammonium provided by the IC measurements, the TOC/TNb based results could be corrected for the underestimation of ammonium which led to a recovery of 95.9 ± 3.1%. The presented methods are applicable for the determination of nitrogen mass balances in lab-scale studies, as well as for the monitoring of mineralization products in field applications.

T.H. Uber, T. Hüffer, S.Planitz, T.C. Schmidt
Characterization of sorption properties of high-density polyethylene using the poly-parameter linearfree-energy relationships
Environmental Pollution (248), May 2019, 312-19

​

​
Abstract

High-density polyethylene (HDPE) is a known sorbent for non-ionic organic compounds in technical applications. Nevertheless, there is little information available describing sorption to industrial HDPE for a broad range of compounds. With a better understanding of the sorption properties of synthetic polymers, environmental risk assessment would achieve a higher degree of accuracy, especially for microplastic interactions with organic substances. Therefore, a robust methodology for the determination of sorbent properties for non-ionic organic compounds by HDPE is relevant for the understanding of molecular interactions for both technical use and environmental risk assessment.

In this work, sorption properties of HDPE material used for water pipes were characterized using a poly-parameter linear free-energy relationship (ppLFER) approach. Sorption batch experiments with selected probe sorbates were carried out in a three-phase system (air/HDPE/water) covering an aqueous concentration range of at least three orders of magnitude. Sorption in the concentration range below 10⁻² of the aqueous solubility was found to be non-linear and the Freundlich model was used to account for this non-linearity. Multiple regression analysis (MRA) using the determined distribution coefficients and literature-tabulated sorbate descriptors was performed to obtain the ppLFER phase descriptors for HDPE. Sorption properties of HDPE were then derived from the ppLFER model and statistical analysis of its robustness was conducted. The derived ppLFER model described sorption more accurately than commonly used single-parameter predictions, based i.e., on log K_o/w. The ppLFER predicted distribution data with an error 0.5 log units smaller than the spLFERs. The ppLFER was used for a priori prediction of sorption by the characterized sorbent material. The prediction was then compared to experimental data from literature and this work and demonstrated the strength of the ppLFER, based on the training set over several orders of magnitude.

New Articles Published:

C. Becker, M. A. Jochmann, T. C. Schmidt
An overview of approaches in liquid chromatography flame ionization detection
TrAC Trends in Analytical Chemistry 110(2019), 143-9

Abstract
Several attempts to combine high performance liquid chromatography (HPLC) with flame ionization detection (FID) have been made since the 1960s. Elaborated systems were developed to overcome problems such as detector overload by use of organic solvents in HPLC or transfer of non-volatile analytes into FID. Almost twenty years after the first successful applications by solvent evaporation based techniques, subcritical water high temperature liquid chromatography opened the door for novel approaches to combine HPLC with FID. Direct coupling without pre-evaporation steps of signal disturbing organic solvents became possible and new instrumental developments resulted in capillary jet interface systems. These systems are suitable for a broad range of volatile and non-volatile analytes, which led to a significant increase of publications. This review discusses the most important developments of LC/FID coupling and summarizes its field of applications.

Neues ZIM-Projekt bewilligt:

Multi-Ion - Nicht-radioaktive, energetisch variable lonisationseinheit zur schnellen und selektiven Schadstoffanalyse in Baustoffen auf der Basis der FAIMS-Technologie
Laufzeit: 1.10.2018-31.07.2021

Ziel dieses Projektes ist es, eine nicht-radioaktive, energetisch variable lonisationseinheit zu entwickeln, die in Kombination mit der Gaschromatographie (GC) - lonenmobilitätsspektrometrie (FAIMS) die schnelle Vor-Ort-Analyse von toxikologisch relevanten Substanzen sowohl in älteren, bereits verbauten (Altholz) als auch in neuen Bauprodukten (meist moderner Dämmstoffen) erlaubt. Dabei sollen die Substanzen sowohl qualitativ als auch quantitativ sicher erfasst werden. Als Modellsubstanzen werden Pentachlorphenol, Lindan, Tolylfluanid, Propiconazol sowie Formaldehyd ausgewählt. Die Entwicklung einer geeigneten Probenvorbereitung und Kalibriermethode ist ebenfalls Schwerpunkt des beantragten Projektes. Mit dem zu entwickelnden Gerät werden Hersteller von neuen Bauprodukten ein System zur Verfügung haben, mit dem im Rahmen der laufenden Prozesskontrolle und unter den werkseigenen Bedingungen die Produktemissionen überprüft werden können. So könnte sehr schnell auf den Produktionsprozess eingewirkt werden um die Schadstoffemission zu kontrollieren und schließlich zu senken.

New Articles Published:

J. Terhalle, P. Kaiser, M. Jütte, J. Buss, S. Yasar, R. Marks, H. Uhlmann, T. C. Schmidt, H. V. Lutze
Chlorine dioxide-Pollutant transformation and formation of hypochlorous acid as a secondary oxidant
Environm. Sci. Technol. 2018, 52, 9964-71

Abstract
Chlorine dioxide (ClO₂) has been used as a disinfectant in water treatment for a long time, and its use for micropollutant abatement in wastewater has recently been suggested. Surprisingly, a mechanistic understanding of ClO₂ reactions in (waste)water matrices is largely lacking. The present study contributes to this mechanistic understanding by performing a detailed investigation of ClO₂ reactions with organic matter using phenol as a surrogate for reactive phenolic moieties. A concept for indirectly determining HOCl using 2- and 4-bromophenol was developed. The reaction of phenol with ClO₂ formed chlorite (62 ± 4% per ClO₂ consumed) and hypochlorous acid (HOCl) (42 ± 3% per ClO₂ consumed). The addition of ClO₂ to wastewater (5 × 10⁻⁵ M ClO₂) resulted in 40% atenolol and 47% metoprolol transformation. The presence of the selective HOCl scavenger glycine largely diminished their transformation, indicating that atenolol and metoprolol were transformed by a fast reaction with HOCl (e.g., k (atenolol + HOCl) = 3.5 × 10⁴ M⁻¹ s⁻¹) that formed in ClO₂ reactions with the wastewater matrix. The formation of HOCl may thus increase the number of transformable micropollutants in ClO₂ applications. However, chlorine related byproducts may also be formed.

O. Knoop, M. Woermann, H.V. Lutze, B. Sures, T.C. Schmidt
Ecotoxicological effects prior to and after the ozonation of tamoxifen
Journal of Hazardous Materials, 358 (108), 286-93

A.R. Ribeiro, B. Sures, T.C. Schmidt
Cephalosporin antibiotics in the aquatic environment: A critical review of occurrence, fate, ecotoxicity and removal technologies
Environmental Pollution 241(2018), 1153-66

Abstract

A. Barion, P. Balsaa, F. Werres, U. Neuhaus, T.C. Schmidt
Stability of organochlorine pesticides during storage in water and loaded SPE disks containing sediment
Chemosphere, 210 (2018), 57-64

Abstract
With regard to the Water Framework Directive (WFD) and the required investigation of the whole water sample including suspended particulate matter (SPM), a storage stability study was conducted to determine the suitable storage time and conditions of 21 organochlorine pesticides (OCPs) spiked in water samples and pre-concentrated on solid-phase extraction disks (SPE disks). Furthermore, this work demonstrates the behaviour of three different certified sediment reference materials (CRMs) contaminated with OCPs in water samples as well as loaded on SPE disks under different temperature conditions and storage time periods. Extracts collected on SPE disks were stored for 3, 14 and 30 days at both 4 °C and −18 °C in darkness covered in (a) freezer bags and (b) aluminum foil. With few exceptions the results of these tests demonstrate stability of OCPs up to 30 days at −18 °C. The recoveries for most substances range between 84% and 133%. Furthermore, the stability of OCPs in water samples additionally spiked with CRM up to 500 mg and stored at a temperature of 4 °C in darkness up to 56 days was investigated. The addition of sodium azide enhanced the stability of some substances during storage, especially the endosulfans (I, II) but most substances were stable regardless of sodium azide addition over the entire storage period. An important conclusion of this study is that the storage of loaded SPE disks is an appropriate alternative to storing water samples.

Sina Dobaradaran, Torsten C. Schmidt, Iraj Nabipour, Nahid Khajeahmadi, Saeed Tajbakhsh, Reza Saeedi, Mohammad Javad Mohammadi, Mozhgan Keshtkar, Maryam Khorsand, Fatemeh Faraji Ghasemi
Characterization of plastic debris and association of metals with microplastics in coastline sediment along the Persian Gulf
Waste Management 78(2018), 649–58 

Abstract
This study reports number, size and color distribution, and metal contents of microplastics as well as adherent sediments along the Persian Gulf. Samples were collected from 9 stations in summer 2015 with a sampling time interval of 10 days. Plastic size of 2–5 mm, and ≤0.25 mm with 45 and 33% and white and colorless plastics with 62 and 33% had the highest abundance considering number per m², respectively. In general, the majority of collected plastics (79%) were smaller than 5 mm (defined size for microplastics). The mean Al, Fe, Mn, Cd, Cr, Ni, Pb, Cu contents of plastic fragments were 115, 531, 32.2, 0.035, 0.915, 2.03, 4.59, and 3.6 μg g⁻¹, respectively while the mean Al, Fe, Mn, Cd, Cr, Ni, Pb, Cu contents of sediments were 186, 3050, 127, 0.81, 5.01, 14.5, 48.6 and 5.43 μg g⁻¹ respectively. There were significant differences between the abundance of plastic items as well as the all examined metal concentrations of microplastics and sediments at different sampling times. As there is no regular cleanup program in the studied areas, significant differences between plastic items number at different sampling times (with higher plastic items number at the first day of sampling) showed that a large number of plastic items may enter from beaches to the sea and become available to marine organisms.

Torsten C. Schmidt
Recent trends in water analysis triggering future monitoring of organic micropollutants
Analytical and Bioanalytical Chemistry 410(17) 2018, 3933–41

Jahresbericht 2017 der IAC

Der Jahresbericht 2017 der Instrumentellen Analytischen Chemie ist fertig gestellt und steht zum Download bereit.

Das ZWU stellt sich und einen Auszug seiner Aktivitäten in der aktuellen UNIKATE-Ausgabe „Herausforderung Wasserforschung –lokal, regional und global“ vor.

Den aktuellen Band finden Sie hier als pdf Version zum Download: UNIKATE 51

mehr zu „UNIKATE-Band zur Wasserforschung...“

New Articles Published:

A.R. Ribeiro, H.V. Lutze, T.C. Schmidt
Base-catalyzed hydrolysis and speciation-dependent photolysis of two cephalosporin antibiotics, ceftiofur and cefapirin
Water Research 134(2018), 253-60

Abstract
Lately, special attention has been given to veterinary cephalosporin antibiotics due to their broad activity spectrum and significant consumption. Indeed, the determination of hydrolytic and photolytic kinetics provides a better comprehension of the undesired persistence of cephalosporins in aqueous matrices. In this work, the two widely used veterinary antibiotics ceftiofur (CEF) and cefapirin (CEPA) showed high instability under alkaline conditions, degrading in few minutes at pH > 11. In buffered solutions at neutral pH and natural temperature (T = 22 ± 1 °C), both drugs presented moderate stability (t½ = 3 d, CEPA and 1.4 d, CEF). Our study also demonstrated that CEPA and CEF speciation did not significantly influence the direct photolysis rates. Using a simulated water disinfection set-up (λ = 254 nm), all ionic species of CEF and CEPA presented fast and similar pseudo-first order degradation rates, k^app 0.0095 ± 0.0004 and 0.0092 ± 0.001 cm² mJ^-1, respectively. Furthermore, using surface water in hydrolysis experiments, CEF demonstrated significant matrix-dependent stability with a half-life (t½ = 14.7 d) tenfold higher than in buffered solutions. In contrast, CEPA presented a very similar hydrolysis rate in river water (t½ = 4.2 d) and a subtle faster photo-degradation rate in this same matrix (k^app 0.0128 ± 0.001 cm² mJ^-1), highlighting the importance of disinfection radiation for cephalosporin depletion in aqueous environments.

G. Renner, T.C. Schmidt, J. Schram
Analytical methodologies for monitoring micro(nano)plastics: Which are fit for purpose?
Current Opinion in Environmental Science & Health 1 2018, 55-61(55-61)

H.L. Wiegand, C.T. Orths, K. Kerpen, H.V. Lutze, T.C. Schmidt
Investigation of the Iron–Peroxo Complex in the Fenton Reaction: Kinetic Indication, Decay Kinetics, and Hydroxyl Radical Yields
Environmental Science & Technology 51(24) 2017, 14321-9
DOI: 10.1021/acs.est.7b03706

Abstract

The Fenton reaction describes the reaction of Fe(II) with hydrogen peroxide. Several researchers proposed the formation of an intermediate iron–peroxo complex but experimental evidence for its existence is still missing. The present study investigates formation and lifetime of this intermediate at various conditions such as different Fe(II)-concentrations, absence vs presence of a hydroxyl radical scavenger (dimethyl sulfoxide, DMSO), and different pH values. Obtained results indicate that the iron–peroxo complex is formed under all experimental conditions. Based on these data, stability of the iron–peroxo complex could be examined. At pH 3 regardless of [Fe(II)]₀ decay rates for the iron–peroxo complex of about 50 s^–1 were determined in absence and presence of DMSO. Without DMSO and [Fe(II)]₀ = 300 μM variation of pH yielded decay rates of about 70 s^–1 for pH 1 and 2 and of about 50 s^–1 at pH 3 and 4. Hence, the iron–peroxo complex becomes more stable with increasing pH. Furthermore, pH-dependent hydroxyl radical yields were determined to investigate whether the increasing stability of the intermediate complex may indicate a different reaction of the iron–peroxo complex which might yield Fe(IV) instead of hydroxyl radical formation as suggested in literature. However, it was found that hydroxyl radicals were produced proportionally to the Fe(II)-concentration.

F. Itzel, K.S. Jewell, J. Leonhardt, L.Gehrmann, U. Nielsen, T.A. Ternes, T.C. Schmidt, J. Türk
Comprehensive analysis of antagonistic endocrine activity during ozone treatment of hospital wastewater
Science of The Total Environment 624(2018), 1443-54

H.V. Lutze, J. Brekenfeld, S.Naumov, C. von Sonntag, T.C. Schmidt
Degradation of perfluorinated compounds by sulfate radicals – New mechanistic aspects and economical consideration
Water Research 129(2018), 509-19

Mülheim Water Award 2018 open for application

The Mülheim Water Award 2018 will open for application on 1st December 2017. The Award is endowed with EUR 10.000, sponsored jointly by RWW Rheinisch-Westfälische Wasserwerksgesellschaft and GERSTEL, and coordinated by IWW Water Centre. The Mülheim Water Award aims at applied research and development projects as well as the implementation of innovative concepts for drinking water supply and water analysis.

Topic of the current submission is: "Innovations for water systems and water analysis for sustainable water management and safe and secure drinking water supply". Application deadline is February 28, 2018.

Natural or legal persons, groups of persons or institutions from Europe may apply for the Mülheim Water Award with projects delivering innovative procedures, solutions, products and concepts. Wanted for application are innovative, practice-orientated concepts as well as ready-for-use solutions to meet future challenges in water systems and water analysis.

The application procedure: Interested parties initially submit a short application. The application form will be available until February 28, 2018 at www.muelheim-water-award.com. From the pool of submitted applications, the jury will identify the most promising candidates, and will request information that is more detailed. Candidates selected for this second stage have good chances for the Mülheim Water Award 2018.

The Mülheim Water Award was first granted in 2006. In five competition rounds, more than 100 applications from 20 different European countries were submitted, covering the entire range of water management topics.

For more information visit www.muelheim-water-award.com.

Contact

Coordinating office of the Mülheim Water Award
c/o IWW Rheinisch-Westfälisches Institut für Wasser Beratungs- und Entwicklungsgesellschaft mbH
Peter Lévai
Moritzstraße 26
45476 Mülheim an der Ruhr
Germany

Phone: +49 208 40303-435
Fax: +49 208 40303-80
E-Mail: info@muelheim-water-award.com
Internet: www.muelheim-water-award.com

New Articles Published:

A.R. Ribeiro, B. Sures, T.C. Schmidt

Ecotoxicity of the two veterinarian antibiotics ceftiofur and cefapirin before and after photo-transformation
Science of The Total Environment 619–620(2018), 866–73

(HO)(H₃C)₂CH + O₃ → [(HO)(H₃C)₂C⁺ + HO₃⁻]_cage → (HO)(H₃C)₂C⁺ + HO₃⁻ → (H₃C)₂CO + H₂O + O₂

Arguments supporting this proposed mechanism are: high exergonicity of reaction (ΔG = −234 kJ mol⁻¹ for the first two steps), low HO yield - (2.4 ± 0.5)% and high acetone yield - (87.2 ± 1.5)%. Other oxidation products detected within the system are acetaldehyde - (1.4 ± 0.1)%, formaldehyde - (4.0 ± 0.1)%, acetic acid - (2.8 ± 0.2)%, formic acid - (0.6 ± 0.2)% and hydrogen peroxide - (1.5 ± 0.1)%. The temperature dependence of the second order rate constant for the reaction 2-propanol + O₃ → products is ln k_II = 29.64–8500 × T⁻¹. The activation energy and pre-exponential factor derived from this relationship are (71 ± 3) kJ mol⁻¹ and (7.5 ± 6.4) × 10¹² M⁻¹ s⁻¹, respectively. At 23 °C, the second order rate constant is k_II = (2.7 ± 0.1) M⁻¹ s⁻¹. The low reaction rate can be explained by the transfer of one hydride ion from 2-propanol to electrophilic ozone.

S. Wacławek, H.V. Lutze, K. Grübel, V.V.T. Padil, M. Černík, and D.D.Dionysiou:
Chemistry of persulfates in water and wastewater treatment: A review
Chem. Eng. J., 2017. 330(Supplement C): p. 44-62.

Neues ZIM-Projekt bewilligt:

Schnelle Vor-Ort-Analytik zur Detektion von Pestiziden in Wässern mittels 2D-Ionenmobilitätsspektrometrie (Hydro-2D-DMS)
Laufzeit: 1.11.2017-31.12.2019

Ziel des Projektes ist die Entwicklung eines kostengünstigen Systems, welches die schnelle Vor-Ort-Analyse von vier der in der WRRL aufgenommenen Substanzen (Quinoxyfen, Cybutryn, Dichlorvos, Terbutryn) als Analyten in Wässern mit unterschiedlichen Matrixbestandteilen unter Einbeziehung der rechtlich geforderten Grenzwerte erlaubt.
Zur Anwendung kommen soll ein Verfahren basierend auf der Technik der differentiellen Ionenmobilitätsspektrometrie. Herkömmlich zur Analyse verwendete DMS-Systeme sind beschränkt auf eine festgelegte Frequenz (ca. 1MHz) der elektrischen Felder. Zur Verbesserung der Leistungsfähigkeit soll im Rahmen dieses Projektes ein Detektor entwickelt werden, der eine Erweiterung des detektierbaren Massenbereiches erlaubt und eine hohe Nachweisempfindlichkeit haben soll. Probeneingabesystem und Ionenquelle sind an das Detektormodul anzupassen. Neben der Konstruktion und des Baus des Prototyps sind Optimierung der experimentellen Parameter, Kalibrierung sowie die Analyse realer Wässer mit unterschiedlicher Zusammensetzung ein weiterer Schwerpunkt des Projektes.

Neues DFG-Projekt bewilligt: „Charakterisierung des Metaboloms von P. aeruginosa im Biofilm als Lungeninfektionsmodell“

​​Im Rahmen dieses Projektes wird das Metabolom von P. aeruginosa unter lungenadaptierten Bedingungen als Biofilm charakterisiert. Um dies zu realisieren, soll ein Beprobungssystem für die Anzucht von P. aeruginosa entwickelt werden, welches es erlaubt aus dem Nährmedium, dem Biofilm und dem Dampfraum zeitabhängig Proben zu entnehmen. Der verfolgte Ansatz über das drei-Phasen-System erlaubt es, detektierte und charakterisierte Verbindungen entsprechend als Substrate oder Stoffwechselprodukte einzuordnen. Über verschiedene Extraktionsstechniken soll eine möglichst umfangreiche Anreicherung der gebildeten Metabolite erreicht werden.

Die qualitative und quantitative Bestimmung ausgewählter Metabolite erfolgt mittels GCxGC-EI-MS und LC+LC-IM-qTOF-MS. Die dabei notwendige Methodenentwicklung umfasst die Probenanreicherung und Optimierung relevanter experimenteller Parameter wie zum Beispiel, Auswahl der stationären Phasen, Analysenzeit in der zweiten Dimension (Modulationszeit) und Flussraten.

Durch die Zugabe von Benzothiazol als interner Standard zum Medium soll außerdem die Anreicherung, Diffusion und Verteilung der potentiellen Stoffwechselprodukte zwischen allen drei Phasen simuliert, untersucht und kontrolliert werden.

Anhand der Ergebnisse soll überprüft werden, ob P. aeruginosa über die im Dampfraum detektierten Metabolite repräsentiert wird und so eine Identifizierung von P. aeruginosa ausschließlich über die Dampfraumbeprobung möglich ist.

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In this project, the metabolome of P. aeruginosa will be characterized considering lung adapted conditions by using a biofilm as a lung infection model. Therefore, a sampling system for the cultivation of P. aeruginosa will be developed, which enables the sampling of the culture medium, the biofilm and the headspace over time. This three-phase approach allows the classification of detected and characterized substances as substrates or metabolites. A comprehensive preconcentration of the metabolites shall be achieved by application of various extraction techniques.

The qualitative and quantitative determination of selected metabolites will be carried out by GCxGC-EI-MS and LC+LC-IM-qTOF-MS. The sample preconcentration and experimental parameters e.g. stationary phase, analysis time in the 2^nd dimension (modulation time) and flow rates will be optimized. 

As an internal standard, Benzothiazole will be added to the culture medium in order to investigate and control the preconcentration, diffusion and distribution of the potential metabolites.

Based on the results, it shall be verified if P. aeruginosa is represented by detecting only the metabolites in the headspace of a biofilm sample. This should answer the question whether the identification of P. aeruginosa is possible only by head space analysis or not.

Unikids:
„Wasser baut Brücken, aber hat es auch ein Gedächtnis?“

​​

​Am 8. März 2017 fand die Auftaktveranstaltung der „Unikids“ in diesem Frühjahr statt. 600 Kinder im Alter zwischen 8-12 Jahren erhielten passend zum Thema ein blaues T-Shirt und sahen ein bisschen aus wie Wassertropfen. Gespannt und aufgeregt verfolgten sie eine Stunde lang die Vorlesung von Torsten Schmidt, Ursula Telgheder und Claudia Ullrich zum Thema Wasser unter dem Titel „Wasser baut Brücken, aber hat es auch ein Gedächtnis?“. Mit anschaulichen Beispielen, Filmausschnitten  und eindrucksvollen Experimenten wurden die Eigenschaften von Wasser und ihre Wirkung auf Mensch und Umwelt nahegebracht. 

​​

​​​Besonders begeistert waren die Kinder von der Wasserbrücke, die zwischen zwei Gefäßen beiAnlegen einer sehr hohen Spannung entsteht und den bei verdunkeltem Hörsaal deutlich sichtbaren Überschlägen. Im zweiten Teil erfuhren die Kinder, warum es so viel  Hokuspokus im Wasserbereich gibt, z. B. das angebliche Wassergedächtnis. An einem einfachen Beispiel wurde ihnen gezeigt, wie sie mit wissenschaftlicher Methodik Unsinn entlarven können.

​​

Den Kindern hat die Vorlesung sichtlich viel Spaß gemacht, aber auch das Team war begeistert von den aktiven Zuhörern.

Neue Auflage erschienen:

​
​

Die verschiedenen Bücher von Prof. Georg Schwedt zur analytischen Chemie gelten bereits als Klassiker. Dazu trägt das Konzept der Verbindung von Grundlagen, Methoden und Praxis bei, aber auch die hochwertige graphische Gestaltung. Abbildungen aus „dem Schwedt“ finden sich sicherlich in allen Vorlesungen zur analytischen Chemie wieder. Das fundamentale Lehrbuch „Analytische Chemie“ ist im Dezember 2016 nun in der dritten Auflage bei Wiley-VCH erschienen. Alle relevanten Aspekte der Analytischen Chemie werden in diesem Lehrbuch, das gleichzeitig auch als Referenz für Praktiker dient, umfassend und klar auf den Punkt gebracht. Ab dieser Auflage wird das Lehrbuch nicht mehr von Prof. Schwedt alleine verantwortet, sondern unter Beteiligung der beiden Professoren für analytische Chemie an der Universität Duisburg-Essen, Oliver Schmitz und Torsten Schmidt. Die beiden haben in dieser Auflage Kapitel inhaltlich neu gestaltet, für die infolge der methodischen und technologischen Entwicklungen eine Aktualisierung erforderlich war. So wurden von Oliver Schmitz hauptsächlich die Kapitel über Qualitätssicherung, Massenspektrometrie, chromatographische Trennverfahren und elektrophoretische Trennverfahren überarbeitet. Torsten Schmidt hat vor allem das Kapitel zur Probenvorbereitung aktualisiert und das Grundlagenkapitel ergänzt.

ISBN: 978-3-527-34082-8 Link zum Buch bei Wiley-VCH

Neues ZIM-Projekt bewilligt:

Entwicklung eines kombinierten ln-situ-Sanierungs- und Monitoringverfahrens für die Behandlung von Grundwasserschäden (Luft-Untergrund-Kontamination-Erfassung "LUKE")
Laufzeit: 1.10.2016-31.3.2019

Ziel des Projektes ist die Entwicklung eines preiswerten ln-situ-Verfahrens für die Sanierung von mit BTEX kontaminiertem Grundwasser. Hierfür wird ein spezielles Multiparameter-Lanzensystem zur Aufnahme eines Gasinjektionssystems, zur kontinuierlichen Probenahme sowie zur direkten Bestimmung der Parameter pH-Wert, 0₂-Gehalt, C0₂- bzw. CH₄-Gehalt, Leitfähigkeit und Feuchte im Grundwasserleiter (Aquifer) entwickelt. Hiermit ist sowohl eine Überprüfung der Vitalitätsparameter als auch eine direkte Kontrolle über die Bildung von C0₂ und CH₄ aus Stoffwechselprozessen möglich. Die Sanierung erfolgt durch die reversible Einbringung einer glasfaserverstärkten Polymermembran in den Aquifer, die Sauerstoff auf diffusivem Wege freisetzt. Dieser dient der schadstoffzehrenden Mikrobiologie als Co-Substrat für ihren Stoffwechsel. Gegebenenfalls können über das
Lanzensystem zusätzliche Nährstoffe zugegeben werden. Mit dem System gekoppelt, ist ein modifiziertes FAIMSSpektrometer mit Fernsteuerung, welches eine kontinuierliche Überwachung der Schadstoffkonzentration in den Beobachtungspegeln erlaubt und somit eine schnelle Bewertung der Sanierungseffizienz ermöglicht.

New article published in ABC

New article published in JAAS

A. Kuklya, C. Engelhard, K. Kerpen, Ursula Telgheder, Spectroscopic characterization of a low-temperature plasma ambient ionization probe operated with helium/nitrogen plasma gas mixtures, J. Anal. At. Spectrom., 2016, 31, 1574-1581

http://dx.doi.org/10.1039/C6JA00148C

In this study, a systematic spectroscopic characterization of a low-temperature plasma (LTP) probe operated with He/N₂ gas mixtures is carried out. The influence of several experimental parameters (e.g., different He/N₂ gas mixtures, discharge voltage, and gas flow rate) on the dielectric-barrier discharge afterglow was studied. It was found that an increase of the nitrogen concentration in the helium discharge gas (to values higher than 0.5% N₂) leads to a significant decay of N₂⁺, He, and O emission intensities. At 1% N₂ and 99% He, oxygen emission bands were not detectable and intensity of He and N₂⁺ emission bands were reduced by approximately five times compared to features in a 100% He discharge. Interestingly, the opposite trend was observed for NO, OH, and N₂ species. Here, increasing the N₂ fraction in the discharge gas mixture led to an enhancement of emission intensities. Maximum emission bands intensities of OH, NO, and N₂ were detected at N₂ concentrations of 0.5, 0.6, and 1.0%, respectively. A further increase of the N₂ fraction leads to a decrease of emission intensities for all observed species (OH, NO, N₂, He, and N₂⁺). In general, an increase in discharge gas flow rate resulted in a significant increase of NO emission band intensities for all N₂/He mixtures tested. However, only a minor effect was observed for N₂ emission bands. Increasing the discharge voltage resulted in an increase of emission intensities of all detected species. Combined with spatially resolved investigations of the afterglow, these results are considered helpful to further optimize LTP performance. This is especially important for portable and direct analysis instrumentation, where LTP can be used as the ionization source and lower helium gas consumption is desirable because of cost and availability.

New article published in Water Research

Tekle-Röttering, A., von Sonntag, C., Reisz, E., vom Eyser, C.,
Lutze, H.V., Türk, J., Naumov, S., Schmidt, W., Schmidt, T.C., 2016. Ozonation of anilines: Kinetics, stoichiometry, product identification and elucidation of pathways. Water Research 98, 147-159

Evonik Stipendium für Nerea Lorenzo Parodi

Nerea Lorenzo Parodi erhält durch die Evonik Industries AG ein Stipendium für Ihr Promotionsvorhaben „Aromatische Amine als Biomarker im menschlichem Urin: analytische Methodenentwicklung und epidemiologische Untersuchung“ an der Universität Duisburg-Essen.

Die Evonik Industries AG vergibt 3 Doktorandenstipendien mit dem Ziel der Förderung des hochbegabten wissenschaftlichen Nachwuchses an der Fakultät für Chemie der Universität Duisburg-Essen.

Evonik Scholarship for Nerea Lorenzo Parodi

Nerea Lorenzo Parodi was awarded with a scholarship for the realization of her PhD project “Aromatic amines as biomarkers in human urine: analytical method development and epidemiological studies” at the University of Duisburg-Essen by the Evonik Industries AG.

Evonik Industries AG awards three scholarships for the realization of a Doctoral thesis with the objective of promoting highly talented young researchers at the faculty of Chemistry of the University Duisburg-Essen.

Poster-Preis für Oliver Knoop

Auf der IWA-Konferenz Micropollutants and Ecohazards (MicroPol 2015) im November gewann Oliver Knoop mit seinem Poster "Degradation of Tamoxifen During Ozonation: pH Dependency" den Best Student Poster Award. Damit setze er sich gegen über 50 andere Teilnehmer mit Posterbeiträgen durch.

Drei neue ZIM-Projekte bewilligt:

Schnelle Vor-Ort-Analytik zur Detektion von Sulfonamiden in Wässern mittels 2D-Fluoreszenzspektroskopie (MultiDimSpec)
Laufzeit: 1.10.2015-31.3.2018

Ziel des Projektes ist die Entwicklung eines miniaturisierten Systems, welches die schnelle Vor-Ort-Analyse von ausgewählten Sulfonamiden in Wässern mit unterschiedlichen Matrixbestandteilen unter Einbeziehung der rechtlich geforderten Orientierungswerte erlaubt. Als Detektionsmethode wird die 2D-Fluoreszenzspektroskopie eingesetzt, da aufgrund der intensiven Fluoreszenz der Sulfonamide die Sensitivität groß genug ist, um die als Orientierungswerte geforderten Konzentrationen bestimmen zu können. Die notwendige Selektivität wird durch Aufnahme und multivariater Datenanalyse der Emissionsspektren bei unterschiedlichen Anregungswellenlängen erreicht.
Neben dem in der aquatischen Umwelt häufig nachgewiesenen Antibiotikum Sulfamethoxazol werden als weitere lndikatorsubstanzen p-Toluolsulfonamid, o-Toluolsulfonamid, Benzolsulfonamid, Sulfadiazin und Sulfamethazin gewählt.
Der in Laborversuchen getestete Prototyp wird in ein Multisensorsystem integriert und anschließend in Feldstudien erprobt. Neben der Steuerungssoftware sind komplexe Softwaremodule für die Datenauswertung zu erstellen .

Entwicklung eines DIP-APPI-IMS-Systems zur Qualitätskontrolle von chemischen und pharmazeutischen Produkten (DIPPI-IMS)
Laufzeit: 1.7.2015-31.7.2017

Im Fokus des Forschungsvorhabens steht die Entwicklung eines Direct Inlet Probe - Atmospheric Pressure Photoionization – Ion Mobility Spectrometers (DIP-APPI-IMS) als sensitives, kostengünstiges und schnelles Verfahren für die Produkt- und Qualitätskontrolle in der chemischen und pharmazeutischen Industrie. DasProbenaufgabesystem (DIP) ermöglicht das Einbringen und Verdampfen fester und flüssiger Proben. Nach der Vorabtrennung von Matrixbestandteilen, werden die Analyten mittels Photoionisation bei Atmosphärendruck (APPI) ionisiert und innerhalb weniger Millisekunden im miniaturisierten Ionenmobilitätsspektrometer separiert und detektiert. Die Leistungsfähigkeit des DIP-APPI-IMS-Systems wird anhand der Analyse von ausgewählten Wirkstoffen in Tabletten und Salben geprüft. Als Vertreter flüssiger Proben sind unterschiedliche Speiseöle zu analysieren. Als Beispiel für die Oberflächenanalytik von Produkten sollen Weichmacher in Kunststoffen herangezogen werden. 

Entwicklung einer oxidativen Abwasseraufbereitungsmethode auf der Basis von Chlordioxid (ABC)
Laufzeit: 1.7.2015-31.12.2017

Ziel des Projektes ist die Entwicklung einer neuen Abwasseraufbereitungsmethode zur Elimination von Spurenstoffen und Desinfektion durch Chlordioxid. Wegen der hohen Selektivität von Chlordioxid ist das Potenzial zur Bildung unerwünschter Nebenprodukten schwächer ausgeprägt als bei dem zur Zeit diskutierten Einsatz von Ozon zur weitergehenden Abwasserbehandlung.  Zur Realisierung des neuen Oxidationsverfahrens wird ein von a.p.f  Aqua System AG entwickelter Chlordioxidgenerator an die Abwasseranwendung angepasst und im Rahmen einer mehrmonatigen Pilotierungsphase die Langzeitstabilität des Verfahrens ermittelt sowie eine Abschätzung der Kosten dieses Verfahrens durchgeführt.

Neue Mitarbeiter in der IAC: 

Nenad Stojanovic und Vanessa Hinnenkamp

Promotionspreis der Wasserchemischen Gesellschaft für
Dr. Holger Lutze

Dr. Holger V. Lutze (Universität Duisburg-Essen) erhält 2015 den "Promotionspreis auf dem Gebiet der Wasserchemie – gefördert von der Walter-Kölle-Stiftung". Der Vorstand der Wasserchemischen Gesellschaft, eine Fachgruppe in der Gesellschaft Deutscher Chemiker e.V. (GDCh), konnte diese Auszeichnung 2015 aufgrund hervorragender Arbeiten an zwei Kandidaten verleihen.

Dr. Lutze beschäftigt sich in seiner Arbeit "Sulfate radical based oxidation in water treatment"³ mit einem innovativen radikalbasierten Wasseraufbereitungsverfahren zum Abbau persistenter Schadstoffe.

Dr. Walter Kölle, der 1971 als erster Wissenschaftler mit dem Fachgruppenpreis der Wasserchemischen Gesellschaft ausgezeichnet wurde, richtete 2010 bei der GDCh eine Stiftung ein, um den wissenschaftlichen Nachwuchs in der Wasserchemie zu fördern. Der Promotionspreis auf dem Gebiet der Wasserchemie – gefördert von der Walter-Kölle-Stiftung - wird für herausragende Dissertationen auf den in der Fachgruppe vertretenen wissenschaftlichen Gebieten verliehen, die mit der Gesamtnote sehr gut oder besser bewertet wurden und eine besondere Leistung für die Weiterentwicklung des Fachgebiets darstellen.

Die Verleihung erfolgt einmal jährlich im Rahmen der Jahrestagung der Wasserchemischen Gesellschaft

Prof. Torsten C. Schmidt unter den Preisträgern der UDE Diversity-Preise 2015

Die Universität Duisburg-Essen feierte am 09. Juni 2015 den 3. bundesweiten Diversity-Tag, in dessen Rahmen auch die Diversity-Preise verliehen wurden. Der Diversity-Engagementpreis ging diesmal an die Fakultät für Chemie: Prof. Bettina Siebers und Prof. Dr. Torsten Schmidt