Peter Krebs

Technische Universität Dresden, Dresden, Saxony, Germany

Are you Peter Krebs?

Claim your profile

Publications (120)147.72 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Wastewater treatment plants (WWTPs) are not designed to purposefully eliminate antibiotics and therefore many previous investigations have been carried out to assess their fate in biological wastewater treatment processes. In order to consolidate previous findings regarding influencing factors like the solid and hydraulic retention time an intensive monitoring was carried out in a municipal WWTP in Germany. Over a period of 12 months daily samples were taken from the in- and effluent as well as diverse sludge streams. The 14 selected antibiotics and one metabolite cover the following classes: cephalosporins, diaminopyrimidines, fluoroquinolones, lincosamide, macrolides, penicillins, sulfonamides and tetracyclines.
    No preview · Article · Dec 2015 · Science of The Total Environment
  • Source
    Jin Zhang · Pei Hua · Peter Krebs
    [Show abstract] [Hide abstract]
    ABSTRACT: This study investigates the build-up dynamics of heavy metals on impervious urban surfaces with different antecedent dry-weather periods (ADPs) and land-use types. Solid-phase concentration (mg/kg), surface load (mg/m(2)), and chemical fractionation of Zn, Cu and Cd in bulk- and size-fractionated road-deposited sediment were determined. The inherent correlations among particle size distribution, ADP, land use, and chemical fractionation were analysed by hierarchical cluster analysis. Results show a clear build-up phenomenon of Cu and Zn at a city commercial centre and a highway area. Cd had complex build-up patterns. With regard to chemical fractionation, Zn and Cd could pose higher risks than Cu to aquatic biota after a longer ADP. Special attention should be paid to the significant risk in a rural area because of the high proportion of exchangeable chemical fractionation in terms of the unstable Cd component. Hierarchical cluster analysis indicates that ADP had a strong influence on build-up processes of sediments and associated metals. The metal contents were very dependent on the particle size distribution. However, the chemical fractionation of metals was dependent to a lesser extent on the land-use type. Copyright © 2015 Elsevier B.V. All rights reserved.
    Full-text · Article · Nov 2015 · Science of The Total Environment
  • Jin Zhang · Jiayu Lin · Pei Hua · Thomas Kaeseberg · Peter Krebs

    No preview · Conference Paper · Sep 2015
  • Jin Zhang · Pei Hua · Peter Krebs

    No preview · Conference Paper · Sep 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: The interaction-based hazard index (HIint) allows a prediction of mixture effects different from linear additivity by including information on binary mixtures between the chemicals. The aim of this study is to make a solid estimate on the possible synergistic potential of combined antibiotics and to quantify the subsequent effect for the case of the receiving river Elbe, Germany. Pieces of information on binary interactions between antibiotic groups were used from literature and from knowledge on human antibiotic combination therapy. Applying a moderate and a worst-case scenario, in terms of the interaction magnitude, resulted in 50 to 200% higher environmental risks, compared to the classical assessment approach applying simple concentration addition. A subsequent sensitivity analysis revealed that the data strength for some binary antibiotic combinations is too low to be considered for a solid estimate of synergistic effects. This led to the definition of certain preconditions in order to decide whether or not to include certain interaction information (e.g. the necessary number of interaction studies). The exclusion of information with low data strength resulted in an attenuated risk increase of 20 to 50%, based on the currently available scientific information on binary antibiotic mixtures. In order to include antibiotics with the highest share in the overall risk (macrolides, quinolones, and cephalosporins) as well as their corresponding metabolites, investigations should focus on binary interactions between them. Copyright © 2015 Elsevier B.V. All rights reserved.
    No preview · Article · Aug 2015 · Science of The Total Environment
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A municipal drainage concept resistant to climatic conditions must guarantee a reasonable protection against flooding also taking into account future climatic changes. For this, potential risksfirst have to be identified in the greatest possible detail and existing drainage concepts are, if necessary, adjusted through appropriate measures. Due to the high expense for comprehen­ sive, detailed assessments with a large urban area, a system is developed for the classification of hazards which is based on comparatively simple overdam calculations using a hydrody­ namic sewer network model. Extensive risk analyses and adjus­ ting measures are to be carried out first in conjunction with a complex coupled sewer network and two-dimensional flooding simulations for the identified relevant areas. The developed ap­ proaches were tested an the example of the Dresden city centre. Thefi.ndings from the described proj ect flow not only into con­ ceptual but also into practical planning and the decisions with the Dresden municipal d rainage.
    Full-text · Article · Aug 2015
  • Source
    Jin Zhang · Pei Hua · Peter Krebs
    [Show abstract] [Hide abstract]
    ABSTRACT: This study showcases the chemical fractionation and primary source identification of Cu, Zn and Cd in road-deposited sediment. Results show that Zn and Cd were identified as easily mobilised and biologically available metals that pose high risks to the receiving aquatic environments. However, Cu was released in substantial amounts only under relatively extreme conditions. With the assistance of principal component analysis and chemical fractionation, two primary contributors to heavy metals in road-deposited sediment were tentatively identified as vehicle-related sources (especially, auto brake pad erosion for Cu and tyre debris for Zn) and atmospheric deposition (especially for Cd).
    Full-text · Article · Jul 2015 · Water Science & Technology
  • Source
    Jin Zhang · Pei Hua · Peter Krebs

    Full-text · Dataset · Jul 2015
  • Mitra Nikpay · Detlef Lazik · Peter Krebs
    [Show abstract] [Hide abstract]
    ABSTRACT: Surfactants are the main active agents in detergents products. Our investigation dealt with the effects of surfactants as a wastewater constituent on the infiltration process of wastewater through saturated soil. In order to more closely observe the flow’s interaction, in a laboratory experiment, a 2D Plexiglas model was filled with fine-grained soil and saturated with degassed water. The particle-free artificial laboratory wastewater was created by adding a commercially available detergent to degassed tap water producing a surfactant concentration with the strength equivalent of up to about 15 times of its critical micelle concentration. The visualization of flow was improved by adding a brilliant blue dye tracer enhancing the color contrast. Photographs were taken from the 2D model using conventional imaging equipment and were processed by image analysis to distinguish the dynamic flow interface between dyed and non-dyed areas. Primarily, the images of vertical flows were analyzed after reducing the contrast range. Next, utilizing an image analysis method, 2D images were reconstructed into 3D visualization models. Three-dimensional and cross-sectional images of the fluid–fluid–soil boundary layer revealed a rapid solute transport prevailing at the dynamic interfaces. This was confirmed with image analysis showing geometric irregularities on the soil surface.
    No preview · Article · Jun 2015 · Environmental Earth Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Predicting the input loads of antibiotics to wastewater treatment plants (WWTP) using certain input data (e.g. prescriptions) is a reasonable method if no analytical data is available. Besides the spatiotemporal uncertainties of the projection itself, only a few studies exist to confirm the suitability of required excretion data from literature. Prescription data with a comparatively high resolution and a sampling campaign covering 15 months were used to answer the question of applicability of the prediction approach. As a result, macrolides, sulfamethoxazole and trimethoprim were almost fully recovered close to 100% of the expected input loads. Nearly all substances of the beta-lactam family exhibit high elimination rates during the wastewater transport in the sewer system with a low recovery rate at the WWTP. The measured input loads of cefuroxime, ciprofloxacin and levofloxacin fluctuated greatly through the year which was not obvious from relatively constant prescribed amounts. The latter substances are an example that available data are not per se sufficient to monitor the actual release into the environment. Furthermore, the extensive data pool of this study was used to calculate the necessary number of samples to determine a representative annual mean load to the WWTP. For antibiotics with low seasonality and low input scattering a minimum of about 10 samples is required. In the case of antibiotics exhibiting fluctuating input loads 30 to 40 evenly distributed samples are necessary for a representative input determination. As a high level estimate, a minimum number of 20-40 samples per year is proposed to reasonably estimate a representative annual input load of antibiotics and other micropollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · Jun 2015 · Water Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Due to rapid economic development and population growth, China is facing severe water problems that include sea-level rise and increasing salinization, floods, water pollution, water shortage, soil erosion and ecosystem deterioration, as well as biodiversity loss. In recent decades, China is progressively more concerned with its water issues that are now at the center of social and political attention. Having to overcome similar challenges, Germany has taken a leading role in the field of water sciences and tech- nology. In particular, China can benefit from the lessons learnt in Germany concerning the rehabilita- tion of water resources in areas heavily affected by chemical industry and mining after the reunification in 1989. German-Chinese cooperation in water sciences started over 25 years ago and dealt with increasing challenges in the 21st century. Following the open space workshop during the Water Research Horizon Conference in Berlin 2014, this article provides a view of some of the challenges and potential opportunities of German-Chinese cooperation in water science and technology.
    Full-text · Article · Feb 2015 · Environmental Earth Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Urban areas are among the main sources which release antibiotics into the environment. The fate of antibiotics during their passage through the human body, the sewer system and the waste water treatment processes can be estimated and used for ecological risk assessment. The present approach deals with the possibility of addressing the ecological impact on individual trophic levels using a probability function to attenuate the classical PNEC approach. The species sensitivity distribution (SSD) is based on available long-term toxicity data and was fitted using the Hill-equation. The species-related toxicity threshold was merged with the slope characteristics gathered from SSD to express the risk probability of each species level. The results for algae and crustaceans show that azithromycin, clarithromycin and ciprofloxacin contribute the highest risk portions to the risk index (RI). The determined RI for fish was found to be below the threshold value of 1 and thus no risk is expected for this species.
    No preview · Article · Jan 2015 · Stochastic Environmental Research and Risk Assessment
  • Mitra Nikpay · Detlef Lazik · Peter Krebs
    [Show abstract] [Hide abstract]
    ABSTRACT: Leakage of wastewater from sewer lines may result in contamination of soil and groundwater. The widespread use of detergents is causing relatively high concentrations of surfactants in wastewater. We studied the effects of surfactants on the infiltration process of wastewater through soil. To that aim, in a laboratory experiment three micro-pore glass filters were installed. A laboratory wastewater substitute was created by adding a commercially available detergent to degassed tap water producing surfactant concentrations of 100, 200 and 400 mg l−1. Rapid changes in permeability after using the surfactant solution were detected. These were further examined during a process of washing the glass filters with water. The experimental results indicated that changes in permeability were induced by significant adsorption of surfactant molecules on the solids surfaces and thus reducing the size of the pores. Higher levels of permeability changes were detected for higher surfactant concentrations. Additionally, the efficiency of washing process of an adsorbed surfactant molecular layer at the pore surfaces was greater that before the critical micelle concentration.
    No preview · Article · Jan 2015 · Environmental Earth Sciences
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The International Water Research Alliance Saxony (IWAS) is addressing the global challenges concerning water quality in the areas of drinking water and sanitation, agricultural irrigation and the quality of surface and ground waters, as well as developing specific ecosystem-relevant services to be implemented on an exemplary basis in selected model regions. Locations (model regions) have been selected in Eastern Europe (R1), Central and Southeast Asia (R2 and R3), the Middle East (R4) and Latin America (R5) that are representative international regions with respect to climate, land use and demographic change (Ibisch et al., Helmholtz Centre for Environmental Research—UFZ, Department of Aquatic Ecosystem analysis and management, 2013). The causes of water problems and the relevant boundary conditions vary from region to region (Borchardt and Ibisch, Integrated water resources management in a changing world : lessons learnt and innovative perspectives, pp 225, 2013). Mongolia and Vietnam were selected model regions in the first IWAS phase; the research was transferred and continued in one of the cross-cutting projects in IWAS II (Vietnam → capacity development) or in the frame of related project activities in Central Asia (R2 Mongolia, Karthe et al., Environ Earth Sci, doi:10. 1007/ s12665-014-3789-1, 2014). The IWAS consortium exists on scientific institutions like the Technische Universität Dresden and the Helmholtz Centre for Environmental Research—UFZ, Leipzig, as well as partners from industry like the Stadtentwässerung Dresden GmbH (SE-DD), DREBERIS—Dresden consulting for international strategies, and itwh—institute for technical-scientific Hydrology, Hanover. This thematic issue compiles the most important scientific results of the second phase of the IWAS project. The project itself and findings of the first phase were already introduced in a previous special issue by Kalbus et al. (Environ Earth Sci 65:1363–1366, 2012). Main results: The IWAS project is structured by the model regions (R) as well as by cross-cutting activities scenario analysis (Q1), technology development (Q2), governance (Q3) and capacity development (Q4).
    Full-text · Article · Dec 2014 · Environmental Earth Sciences
  • Source

    Full-text · Article · Dec 2014 · Environmental Earth Sciences
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The release of antimicrobial substances into surface waters is of growing concern due to direct toxic effects on all trophic levels and the promotion of antibiotic resistance through sub-inhibitory concentration levels. This study showcases (1) the variation of antibiotics in sanitary sewage depending on different timescales and (2) a method to assess the antibiotic resistance based on an inhibition test. The test is based on the measurement of the oxygen uptake rate (OUR) in wastewater samples with increasing concentrations of the selected antibiotic agents. The following antibiotics were analysed in the present study: clarithromycin (CLA) was selected due to its high toxicity to many microorganisms (low EC50), ciprofloxacin (CIP) which is used to generally fight all bacteria concerning interstitial infections and doxycyclin (DOX) having a broad spectrum efficacy. Results show that CLA inhibited the OUR by approximately 50% at a concentration of about 10 mg L(-1), because Gram-negative bacteria such as Escherichia coli are resistant, whereas CIP inhibited about 90% of the OUR at a concentration equal to or greater than 10 mg L(-1). In the case of DOX, a moderate inhibition of about 38% at a concentration of 10 mg L(-1) was identified, indicating a significant antibiotic resistance. The results are consistent with the corresponding findings from the Clinical and Laboratory Standards Institute. Thus, the presented inhibition test provides a simple but robust alternative method to assess antibiotic resistance in biofilms instead of more complex clinical tests.
    Full-text · Article · Nov 2014 · Water Science & Technology

  • No preview · Conference Paper · Oct 2014
  • Mitra Nikpay · Detlef Lazik · Peter Krebs
    [Show abstract] [Hide abstract]
    ABSTRACT: Leakage of wastewater from sewer lines may result in contamination of soil and groundwater. Our investigation dealt with the effects of surfactant as one of the constituents of wastewater on the infiltration process of wastewater through soil. To that aim, in a laboratory experiment, a column was uniformly packed with glass beads of 0.25–0.50 mm diameter and equipped with sensors to measure local fluid pressure at three observation points along the direction of flow. The artificial laboratory wastewater was created by adding a commercially available detergent to degassed tap water producing surfactant concentrations between 8 and 16 mg l-1. The displacement process of degassed tap water by such a particle-free artificial wastewater was studied by loading the surfactant solution into the saturated glass beads column. Short-term pressure changes were observed while the interface between water and surfactant solution passed the observation points within the column. The pressure peaks increased for higher surfactant concentrations. The theory of growing interface between surfactant solution and clean water by aggregation of monomers to a double layer could be supported by the column experiments.
    No preview · Article · Oct 2014 · International journal of Environmental Science and Technology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: IWRM education: e-learning module on Integrated Water Resources Management The International Water Research Alliance Saxony (IWAS) and the German Secretariat of the International Hydrological Programme of UNESCO and Hydrology and Water Resources Programme of WMO (IHP/HWRP) have jointly developed an e-learning module on IWRM. The video/lecture production and the graphic design were done by A. Weßler from IHP/HWRP Secretariat. This work was funded by the German Federal Ministry for Education and Research (BMBF) within the project ‘‘IWAS—International Water Research Alliance Saxony’’ and by the German Federal Ministry for the Environment (BMU). It would not have been possible without the enormous contribution by participating lecturers.
    Full-text · Article · Oct 2014 · Environmental Earth Sciences
  • Source
    Jin Zhang · Jing Wang · Pei Hua · Peter Krebs

    Full-text · Dataset · Oct 2014

Publication Stats

1k Citations
147.72 Total Impact Points

Institutions

  • 1998-2015
    • Technische Universität Dresden
      • Institute of Clinical Pharmacology
      Dresden, Saxony, Germany
  • 2014
    • University Malaysia Sarawak
      Kuching, Sarawak, Malaysia
  • 2013
    • The University of Sheffield
      Sheffield, England, United Kingdom
  • 2012
    • University of Belgrade
      Beograd, Central Serbia, Serbia