Projects finished

Groundwater treatment for removal of arsenic and chromium(VI) using innovative adsorbing and filtration technologies


Groundwater treatment for removal of arsenic and chromium(VI) using innovative adsorbing and filtration technologies



Duration:01.03.2016 – 31.12.2017

project management / project work:

Prof. Dr.-Ing. M. Ernst / M. Langer


The ACR-Tech project was granted within the „PPP-IKYDA 2016“ call of the German Academic Exchange Service (DAAD). IKYDA is a bilateral scientific fundig measurement of DAAD and the Greec State Scholarship Foundation (I.K.Y.) with the objective to support cooperation between Greec and German research groups, especially between young academics.

Since March 2016, there is a lively exchange with the Aristotle University of Thessaloniki about the removal of arsenic and chromium from groundwater.

  • Investigate innovative technological approaches for efficient arsenic and chromium removal from groundwaters coupled with filtration / membrane filtration
  • Monitor such innovative treatment lab pilots for long term (several months) and evaluate their practical applicability, especially with emphasis to the low energy, low cost, low maintenance and operational requirements
  • Promote mobility, training and specialization of young academics
  • Initiate a closer collaboration for future joint research projects





Duration:01.10.2016 – 30.09.2020

project management / project work:

Prof. Dr.-Ing. M. Ernst / M. Usman, M.Sc.


Arsenic is internationally one of the major pollutants in municipal drinking water and a worldwide concern because of its toxicity and chronic effects on human health. To remove arsenic from drinking water several techniques including adsorption onto iron oxide-based adsorbents exist. Granular ferric hydroxide (GEH, Wasserchemie GmbH & Co. KG, Osnabrück) with individual particle size ranges between 0.320 – 2.0 mm can be applied in fixed bed columns for continuous media filteration. However, this porous media is relatively cost intensive. During industrial production of GEH a fine fraction of grains with particle size less than 0.25 mm is generated that cannot be applied in continuous filtration systems as it leads to rapid clogging of fixed-bed columns. In the current project, arsenic removal is to be achieved using adsorption-low pressure membrane filtration hybrid system.

The fine fractions of GEH and other adsorbents are used for arsenic removal from drinking water in adsorption-membrane hybrid system at various operation conditions. In hybrid system the entire treatment activity (such as adsorption, liquid-solid separation, and sludge accumulation and withdrawal) will be carried out in a single unit. The results will be compared with known transport models (homogeneous surface diffusion model) and, if necessary, model adjustments will be carried out. Model predictions will be based on adsorption equilibrium and kinetic parameters determined from isotherm and batch experiments, respectively.



BMBF-Fördermaßnahme: Intelligente und multifunktionelle Infrastruktursysteme für eine zukunftsfähige Wasserversorgung und Abwasserentsorgung - Wissenschaftliches Koordinierungsvorhaben für Transfer und Vernetzung

BMBF-Fördermaßnahme: Intelligente und multifunktionelle Infrastruktursysteme für eine zukunftsfähige Wasserversorgung und Abwasserentsorgung -
Wissenschaftliches Koordinierungsvorhaben für Transfer und Vernetzung



Finanzierung: BMBF
Laufzeit: 01.01.2013 - 30.06.2016
Projektpartner: Difu - Deutsches Institut für Urbanistik (Projektleitung),
DWA - Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e.V.


Margarethe Langer


Die Folgen des Klimawandels und eine veränderte Demografie stellen weltweit neue Anforderungen an eine nachhaltige Bewirtschaftung von Wasserressourcen. Dies stellt in Deutschland die Infrastrukturen der Wasserversorgung und der Abwasserentsorgung vor erhebliche Herausforderungen, da die Anpassungsfähigkeit der teilweise veralteten Systeme verbessert und neue flexible Lösungen entwickelt werden müssen. Vor diesem Hintergrund fördert das Bundesministerium für Bildung und Forschung (BMBF) im Rahmen des Förderschwerpunktes „Nachhaltiges Wassermanagement" (NaWaM) mit der Fördermaßnahme „Intelligente und multifunktionelle Infrastruktursysteme für eine zukunftsfähige Wasserversorgung und Abwasserentsorgung" (INIS) die Erforschung und Erprobung neuer Ansätze in der Wasserwirtschaft

Die Forschungs- und Entwicklungsvorhaben dieser Fördermaßnahme werden durch ein wissenschaftliches Koordinierungsvorhaben (WK INIS) begleitet. Ziele und Aufgaben sind dabei:

  • Die Durchführung der Öffentlichkeitsarbeit, wie Internetpräsenz, Informationsbroschüren, Newslettern, Flyern, und Pressmitteilungen.
  • Die Vernetzung der Verbundforschungsvorhaben und die Unterstützung des Informationsfluss, insbesondere zu projektübergreifenden Querschnittsthemen.
  • Die Organisation von projektübergreifenden Workshops und Statuskonferenzen.
  • Die Information der Fachöffentlichkeit über die Fördermaßnahme und ihre Ergebnisse.
  • Die Vorstellung von Forschungsergebnissen im Rahmen des bestehenden Bildungsangebots von Difu, DVGW und DWA.
  • Die Einbringung der Forschungsergebnisse in das einschlägige Regelwerk.
  • Die Unterstützung der Überführung von Forschungsergebnissen in die Anwendung und praktische Umsetzung.





Sub-project 2: Effects of cleaning and disinfection procedures on the survival of pathogens in biofilms and their discharge into drinking water under close-to-practice conditions

Sub-project 2: Effects of cleaning and disinfection procedures on the survival of pathogens in biofilms and their discharge into drinking water under close-to-practice conditions


Research partners:Biofilm Centre, Universität Duisburg-Essen (Koordination)
Institut für Hygiene und Öffentliche Gesundheit der Universität Bonn
IWW Zentrum Wasser, Mülheim/Ruhr
Fachgebiet Umweltmikrobiologie, TU Berlin

Funding:BMBF, DVGW und 15 Industriepartner
Duration:01.09.2010 - 28.02.2014

Project management / project work:

Dr. Bernd Bendinger / Dipl.-Biol. Thomas Meier


Pseudomonas aeruginosa (P. a.) and Legionella pneumophila (L. p.) are able to contaminate and persist in drinking water biofilms. It has been observed that after incorporation into biofilms P. a. can switch into a viable but nonculturable (VBNC) state i.e. it is no longer detectable with cultivation methods. In this state individual cells can possibly survive a disinfection with chlorine dioxide and can afterwards switch back into a culturable state. It is to clarify under which operating conditions and with which disinfectants this phenomenon occurs and hopefully also which measures can prevent this. Unlike P. a., L. p. remains in biofilms predominantly in a culturable state for a long time but single cells are also able to survive a disinfection and multiply again.


Long term experiments are performed in two close-to-practice test rigs simulating a household drinking water installation under varying operational conditions (temperature, pipe materials, DOC, nutrient supply). After autochthonous drinking water biofilms have been contaminated with P. a. and L. p. a cleaning procedure and prevalent disinfection procedures are performed. Biofilm and drinking water samples will be analyzed with standard and molecular methods (FISH, qPCR) after contamination and disinfection, in order to quantify the bacteria in their culturable and/or their nonculturable VBNC state. The goal is to define cleaning and disinfection measures for drinking water installations that can ensure an enduring hygienic safety because the cells in the VBNC state will also be inactivated. Thereby the unrecognized distribution of pathogens inside drinking water installations can be prevented and the risk of infection for the consumer can be minimized.


see project homepage

Executive Summary




Chromium removal through iron reductive precipitation in drinking water treatment

Chromium removal through iron reductive precipitation in drinking water treatment


Duration: 01.05.2016 – today

project management / project work:

M. Langer


Chromium is commonly used in a broad range of industrial applications, such as leather tanning, production of steel and other alloys and textile processing. Depending on production conditions chromium can often be found in soil and groundwater. Apart from contamination, chromium can be naturally washed into groundwater by erosion of ophiolithic and metamorphic rocks. In aqueous solutions hexavalent (Cr(VI)) and trivalent chromium (Cr(III)) are the predominant redox species. While Cr(III) at low concentrations is essential for metabolic processes, Cr(VI) is highly toxic due to  its carcinogenic and mutagenic properties. This fact has triggered an ongoing discussion of existing standards in different countries. As a consequence it is expected that the European commission will reduce the acceptable limits of Cr(VI) in drinking water (currently 50 μg/L of total chromium) to much lower values (<10 μg/L of Cr(VI)).

As Cr(VI) does not precipitate readily, chemical reduction followed by precipitation is a widely used technique for Cr(VI) removal. The resulting Cr(III) has low solubility in water and can either be precipitated as Cr(III) hydroxide or adsorbed on iron hydroxides and subsequently being removed from water through filtration. However, in this treatment process the role of natural organic matter has rarely been investigated and is not sufficiently understood. As a result the removal of Cr(VI) from natural organic containing ground water is a delicate task, especially if low concentration of total chromium are targeted.

Recent project results: Download



DVGW project: Removal of dissolved organic carbon from groundwater containing humic acids (decolorization) – possible applications and limits of treatment processes

DVGW project: Removal of dissolved organic carbon from groundwater containing humic acids (decolorization) – possible applications and limits of treatment processes (COL_EX)


DVGW (Förder-Nr. W201719)
Duration: 01.07.2018 – 31.03.2021
Project partner: DVGW-Forschungsstelle TUHH
DVGW-Technologiezentrum Wasser, Außenstelle Dresden
Cooperation of 5 water suppliers in northern/eastern Germany

Project management / project work:

Dr.-Ing. Barbara Wendler, Jakob Kämmler


Many groundwaters exhibit a coloration caused by organic components due to regional deposits of peat or lignite sands in the aquifers.

  • The coloration of drinking water is limited by German Drinking Water Ordinance (spectral absorption coefficient, SAC436 = color, < 0.5 m-1).
  • Though increased coloration by humic substances is typically non-hazardous, it might cause aesthetic problems, leading to complaints by consumers.
  • Increased concentrations of humic substances are undesired, as they increase the bioavailability of the DOC and may be initiators in the formation of disinfection by-products.
  • Groundwaters with high coloration values are typically anaerobic and contain high concentrations of iron and manganese.  Presence of organic components in water may negatively affect removal of iron and manganese

Currently, the DVGW set of rules does not contain any information on process selection to achieve decolorization in the context of groundwater treatment, in a sustainable and cost-efficient manner.



Both in the laboratory and at selected waterworks sites, three technologies (flocculation / precipitation, oxidation, adsorption) are examined for their decolorization efficiency and the respective performance limits. As an innovative method, ozonation with downstream biofiltration is used. This technique is used almost exclusively in surface waters for other treatment purposes (disinfection, odorants, pre-flocculation). Ozone selectively attacks chromophoric molecules and is therefore well suited for decolorization. In contrast to other technologies, no residues (sludge, concentrates) are generated. However, questions about the resulting DOC bioavailability and the formation of bromate depending on technical parameters and water quality have to be answered.

The participating water suppliers offer access to their plants and previous experience in dealing with the problem. Thus, the application possibilities and limitations of the considered methods become clear.

The evaluation of the results of the analyzed treatment processes is carried out with the aim of developing recommendations for action in the DVGW set of rules, as well as minimizing the use of energy and chemicals and the entire life cycle costs.

Recent project results: Download



Decalcification of mobile drinking water systems
Funding:BMWi (Lufo IV), Airbus
Duration:01.08.2012 - 31.01.2015

project management / project work:

Dr. B. Bendinger / Dr. A. Höckendorf


In this project decalcification procedures with organic acids and their impact on water quality are investigated in a mobile drinking water facility.

In mobile drinking water facilities, e.g. on board of aircrafts, fuelling of water with different scaling potentials and heating of the water in the kitchen may lead to partially strong scale deposits. This causes constrictions in water distribution, breakdown of devices for hot water production, and finally an off time of the transport vehicle, when the whole facility has to be decalcified. Conventionally, for decalcification of the potable water system organic acids like acetic acid or citric acid are used. Thereby, the risk of microbial growth arises because bacteria are able to utilize not completely rinsed acid as a food source and consequently their growth is promoted.


For comparable conditions in the decalcification experiments a special facility had been built. Herein pipes can be calcified under defined conditions resulting in reproducible solid calcite deposits in stainless steel tubes.

In a true-to-original mobile drinking water facility these calcified pipes are decalcified with acids in various concentrations and subsequently rinsed with potable water. Afterwards, the facility is operated with a flow-stagnation-program and the water phase is examined under operation conditions in the following weeks. Diverse chemical and microbiological parameters are analyzed including total and dissolved organic carbon (TOC and DOC), calcium carbonate precipitation potential (Dc), total cell count, and colony counts at 20 °C and 36 °C according to the german drinking water directive 1990.

The aim of this study is to find an optimized decalcification procedure which provides a more efficient decalcification performance without microbial regrowth after restart of operation. The existing decalcification instruction will be critically examined and evaluated and in addition recommendations for decalcification will be developed.

Figure 1: (A) Calcified pipes, such as those used for decalcification, (B) pipes after decalcification

Outcomes:The results of this study impact the existing decalcification procedure in the sort and concentration of the applied acid as well as in the quantity and intensity of the rinsing steps with drinking water following the acid treatment. Based on these findings a new decalcification instruction for mobile drinking water systems may be defined.



Energy efficiency/energy saving in water supply
Duration:01.07.2007 - 31.08.2010

project management / project work:

Prof. Dr.-Ing. K. Wichmann / Dr.-Ing. Michael Plath


As part of the debate on the modernization of the water management the energy use is discussed as a part of sustainability and profitability. Especially the specific consumption of electricity is considered. The specific energy requirement depends on the topographical conditions, the structure of the supply area, the type of water extraction, treatment process, the pipe network dimensioning etc. and is in each case different.



Systematic assessment of the energy performance, in collaboration with 14 participating water utilities with approximately 40 water works, allows to determine real operating data. Drawn up together with the catalog of energy saving potentials energy savings can be identified and recommendations can be established. For each water company, there will be a catalog with specific recommendations generated. The participating water companies will ensure that the development of the system is practical and at the same time during the project they achieve better knowledge of energy balances and savings in their own company.

Outcomes:DVGW-Information Wasser Nr. 77
„Handbuch Energieeffizienz/Energieeinsparung in der Wasserversorgung“



BMWi-funding measure: Energy efficiency in water extraction - applied studies and recommendations for practice

BMWi-funding measure: Energy efficiency in water extraction - applied studies and recommendations for practice


Duration:01.07.2014 - 30.06.2018

BWB - Berliner Wasserbetriebe AöR
HWW - Hamburger Wasserwerke GmbH

Project management / project work:

Prof. Dr.-Ing. M. Ernst / Dr.-Ing. M. Beck


With continuously increasing energy costs and the expected contribution of water utilities to reduce greenhouse gas emission, these companies face the challenge of providing drinking water more energy efficient.
The objective of this project is the sustainable improvement of energy efficiency with focus on water extraction including economic aspects.
For this purpose energy saving potentials are examined and the increase of energy efficiency is investigated after implementations of the proposed measures into the technical process. The knowledge and experience gained from the applied research are gathered in recommendations of actions that will allow all german water utilities to contribute effectively to the increase of energy efficiency.



DVGW Research Institute at TUHH is coordinating the research and development project. Goals and tasks are:

  • data collection, preparation of energy audits und planning of measures for energy saving,
  • implementation of measures and monitoring success,
  • presentation of results and development of recommendations of action.
Project page:



Capacity building for optimising water supply through performance indicators with the aim of reducing chemical use, improving energy efficiency and reducing water losses in the distribution network

European Community
10th European Development Fund: ACP-EU Water Facility

Duration:01.01.2013 - 31.12.2015


Implemented partner 1:

Implemented partner 2:

Beneficiary partner:

Supporting partner:

Hamburger Wasserwerke GmbH (HWW), Germany

DVGW-Forschungsstelle TUHH (DVGW-TUHH), Germany

Consulaqua Hamburg Beratungsgesellschaft, Germany

Energy, Water and Sanitation Authority (EWSA), Rwanda

Kigali Institute of Science and Technology (KIST), Rwanda


Project management / project work:

Dr. Christoph Czekalla (HWW) / Dr. Bernd Bendinger (DVGW-TUHH)


Different measures have to be executed in order to improve the completely inadequate providing of water and basic sanitation for the total of 9.3 million inhabitants of Rwanda. Objectives of the actions are to contribute to enhanced and secured long-term supply of clean drinking water to the population of Rwanda by implementation of modern optimization strategies for public water supply based on capacity building and enhancement of technical efficiency.

The DVGW-TUHH is involved in the capacity building and staff training as seen as key factors for sustainable development. DVGW-TUHH will introduce the knowhow on modern optimization strategies for water treatment and supply systems into higher student education at KIST.


DVGW-TUHH will perform following activities:

  • Block lectures at KIST on modern optimization strategies for drinking water treatment and drinking water supply
  • Involvement of KIST representatives and students into project workshops and project activities
  • Supervision of research projects at KIST
  • Initiation of applied research cooperation with KIST
  • Participation in project development, execution and evaluation of project results



Environment: Reduction of the considerable amount of chemicals used for mainly surface water treatment

Energy efficiency: An increase of energy efficiency of supply systems from water abstraction, water treatment to water distribution

Infrastructure: Reduction of technical losses in water distribution

Capacity building: Education of well qualified university graduates able to combat the predominate problems of Rwanda water supply



FlowDetect: Further development and validation of flow cytometry as a fast detection method for bacteria in raw water and drinking water

FlowDetect: Further development and validation of flow cytometry as a fast detection method for bacteria in raw water and drinking water



DVGW, Bonn
Duration:01.10.2017 – 31.03.2020
Project partner:TZW: DVGW-Technologiezentrum Wasser, Karlsruhe   
IWW Zentrum Wasser, Mülheim/Ruhr   
Berliner Wasserbetriebe     
Landeswasserversorgung Stuttgart   
Hamburg Wasser   
Trinkwasserversorgung Magdeburg   

Project management / project work:

Prof. Andreas Tiehm (TZW), Dr. Bernd Bendinger / Anne-Madeleine Trimbach, Dorota Bruniecka-Sulewski


Flow cytometry (FCM) is a powerful method for the quantification of all bacteria in a water sample (total cell count, TCC). After staining with a DNA-specific fluorescent dye every single cell is excited by a laser beam and its light scattering and fluorescence intensity is detected by optical sensors. The combination of different signals gives a specific fingerprint of a water sample showing e.g. the proportion of small cells with a low DNA content (LNA) to big cells with a high DNA (HNA) content.

The measurement of a TCC takes only a few minutes. In contrast culture methods detect only 0.01 to 0.1 % of the TCC and the determination of colony counts according to the german drinking water ordinance require at least 48 hours. The time saving and the availability of mobile and recently also of online-instruments are important arguments for a promising application of FCM in water analysis.

Additionally, FCM can differentiate between live (membrane intact) and dead (membrane damaged) cells which allows the detailed investigation of the efficacy of disinfection methods. Several publications propose the general application of FCM for the surveillance of disinfection methods. However, this has to be regarded critically due to different mechanisms of action of disinfectants - especially with regard to UV-disinfection.

The objective of the project is to determine the potential and the frontiers of this forward-looking method. The FCM should be further developed and validated for different fields of application:

  • Fast measurement of total cell counts (TCC) in different matrices
  • Fast characterization of raw water and drinking water
  • Specific detection of fecal indicators
  • Surveillance of the efficacy of disinfection

The comparison of the results from FCM with classical culture methods should reveal the relevance of FCM data for the assessment of the hygienic quality of the water. For an as far as possible close-to-practice development of flow cytometry real water samples of preferably different compositions from water utilities will be analyzed.


The DVGW-Forschungsstelle TUHH performs the following work program in the overall project:

  • Participation in interlaboratory tests for the determination of TCC, LNA/HNA-ratio and proportion of live (membrane intact) cells
  • Analysis of the microbial dynamics in treatment processes of different raw waters and during distribution (long-distance water main)   
  • Surveillance of disinfection: investigation of the effect of chlorine dioxide on the live/dead differentiation of cells in laboratory experiments with different drinking water qualities
  • Measurement of the effect of different water matrices (e.g. particles, dissolved compounds) on bacterial FCM-signals
  • Hygienic relevance of the data: interpretation of FCM-data and evaluation of their hygienic relevance by comparison with the results from routine culture techniques
  • Adaptation of standard operation procedures (SOPs) for sampling, sample fixation, instrument settings and quality control



BMBF - Collaborative research project in its funding area ReWaM: Parametrization and quantification of groundwater ecosystem services as a basis of sustainable water resource management”

BMBF - Collaborative research project in its funding area ReWaM: Parametrization and quantification of groundwater ecosystem services as a basis of sustainable water resource management”

Subproject 2B: Indicator parameters for evaluation of the microbiological state and activity of anaerobic ground water”


Research partners:

  • Coordination: Helmholtz Zentrum München GmbH, Institut für Grundwasserökologie, Neuherberg
  • DVGW Technologiezentrum Wasser - TZW, Karlsruhe,
  • Justus-Liebig-Universität Gießen, Gießen
  • Bayerisches Landesamt für Umwelt, Zentrale Analytik, Trinkwasser, Augsburg und Hof
  • Gelsenwasser AG, Gelsenkirchen
  • Westfälische Wasser- und Umweltanalytik GmbH, Gelsenkirchen
  • Boden- und Grundwasserlabor GmbH, Dresden
  • Institut für Grundwasserökologie IGÖ GmbH, Landau
  • Limco International GmbH, Konstanz


BMBF – Federal Ministry of Education and Research
Duration:June 2015 – December 2018

project management / project work:

Dr. B. Bendinger /  Anne Madeleine Trimbach, M. Sc.


In Germany, groundwater is the most important resource for drinking water. Due to land use changes, river development, extreme weather events and substance deposition, the quality and availability of groundwater is at risk. To encounter this trend it is essential to develop and standardize new concepts and tools to evaluate the ecological status and the self-cleaning potential of water. Only this allows for a sustainable resource management of groundwater on a regional scale.

The aim of this multidisciplinary project is to develop methods and biological-ecological concepts which are applicable for groundwater monitoring in water management practice. After comprehensive testing and standardization these will be provided to environmental authorities and water management organizations as a modular system. The main tasks of this project network are:

  • Identification and implementation of ecological criteria for evaluating the ecological status of groundwater
  • Standardization of sampling techniques for ecological indicators and development of an online-measurement-system to evaluate the ecotoxicological effects of pollutants
  • Evaluation of the ecosystem services of chosen groundwater systems with regard to extreme weather events
  • Evaluation and validation of concepts and methods at chosen project sites differing in land use
  • Development of guidelines for water management practice
Methodology of subproject Hamburg:

Two third of the drinking water in Germany is produced from groundwater of which a big part is anaerobic groundwater, i.e. it contains no free oxygen and varying concentrations of reduced compounds. These can precipitate upon contact with oxygen from air, thus leading to alterations of a water sample. Therefore, standard methods for examination of water must be adapted to these special conditions. The objective is to obtain a compilation of robust and practicable methods for the evaluation of the microbiological status of anaerobic groundwater.

  • Selection of meaningful indicator parameters for use in anaerobic groundwater
  • Development, adaptation and standardization of selected methods based on anaerobic groundwater samples from the Fuhrberger Feld
  • Comparative measurements between project partners
  • Quantification and characterization of total and biologically degradable organic carbon

Anaerobic groundwater can fulfill an important ecosystem service for the reduction of high anthropogenic nitrate input into near-surface groundwater resulting in low-nitrate groundwater for drinking water production. The responsible process for this is microbiological denitrification. The objective is to determine activity and resilience of the pyrite-dependent nitrate reduction.

  • Establishing of a laboratory test for the measurement of the autotrophic denitrification potential in groundwater samples from the Fuhrberger Feld (activity test)
  • Comparison of the activity measurements with the abundance of denitrifying bacteria or denitrification enzymes with molecular biology
  • Determination of the most important denitrifying bacteria
  • Effects of selected pollutants on the autotrophic denitrification potential in laboratory tests for the evaluation of the sensitivity of this ecosystem service

Associated partner of the subproject is the utility enercity, Hannover with its groundwater abstraction field Fuhrberger Feld where the groundwater samples will be taken.




Effect of natural organic compounds on scaling processes during high-pressure membrane filtration
Duration:01.09.2012 - 31.08.2016

project management / project work:

Prof. Dr.-Ing. M. Ernst / Dipl.-Ing. Jan Benecke


Local water supply shortages are one of the biggest global challenges of today's generation. The only way to extend existing drinking water resources beyond what is available from the water cycle is through water reuse or desalination of sea and brackish water.

At present, the most energy-efficient technology to desalinate saline waters is high pressure membrane filtration using solution-diffusion-membranes (RO: reverse osmosis). However, membrane scaling poses a major challenge on the performance of a reverse osmosis process. Membrane scaling is the deposition, accumulation and growth of crystals on the membrane surface and may occur as a consequence of surpassing solubility limits of different salts (e.g. gypsum/CaSO4∙2H2O) during filtration. Scaling layers block the membrane surface and may create an additional hydraulic resistance thus leading to loss in filtration performance and possible process failure.

Numerous publications demonstrate that the presence of impurities, such as natural organic matter (NOM), can interfere with the crystallization process in aqueous solutions. In the case of membrane desalination processes, it has been shown that interactions between NOM and scaling mechanisms may alter the overall performance. An improved knowledge of these interactions supports the development of tailored measures to prevent or minimize membrane scaling.



Different experimental setups including a lab-scale automated high pressure membrane desalination system and experimental procedures were established to investigate the impact of NOM on crystallization of common scalants in aqueous solution and RO desalination. First results show that the presence of NOM retards crystallization in aqueous solution. During RO desalination, the presence of NOM leads to distortion of crystal development and growth, i.e. a change in crystal size, morphology and number. Future investigations aim at assessing the impact of membrane surface properties altered by NOM accumulation on scaling processes. For characterization of relevant NOM fractions in natural waters, procedural experiments are supplemented with size exclusion chromatography (LC OCD) and fluorescence spectroscopy. Crystals and scaling layers are characterized by means of microscopic investigations.



Klimzug-Nord - Teilprojekt 1.2
Groundwater impact due to climate change in the tidally influenced Elbe river basin - quantification of the cause-effect relationships and countermeasures
Duration:01.04.2009 - 31.12.2014

Project magagement / project work:

Prof. Dr. W. Schneider / J. Palm / A.-G. Meier


Climate change is expected to influence the groundwater regime of low lying areas of the River Elbe valley. Higher groundwater potentials can lead to soil wetness. Due to sea level rise brackish water will travel upstream the river and can intrude further into the aquifer.

Within this project interdependencies between climate change and groundwater shall be quantified. Also, counter measures shall be identified which lead to an optimal adaptation to a changing environment.
Therefore two study areas are focused: the river island Hamburg Wilhelmsburg as well as an area within the Elbe valley called “Altes Land”.


Outcomes:see Project homepage



Klimzug-Nord - Teilprojekt 3.2
Adaptation strategies in the biosphere reserve Niedersächsische Elbtalaue using the example of floodplain habitats

Teilprojekt 3.2 Anpassungsstrategien im Biosphärenreservat Niedersächsische Elbtalaue am Beispiel der Auenlebensräume


Finanzierung: BMBF
Laufzeit: 01.04.2009 - 31.12.2014

Projektleitung / Projektbearbeitung:

Prof. Dr. W. Schneider / Herr M. Scharnke


Die Funktionenvielfalt der Auenlandschaft spiegelt sich in dem dichten Beziehungsgeflecht wider, das aus landwirtschaftlichen Interessen, Anforderungen der Hochwasservorsorge, einer touristischen Nutzung und naturschutzfachlichen Belangen geknüpft ist. Insofern ist die grundlegende Fragestellung, wie der derzeit noch häufig sektoral und ressortspezifisch geprägte Umgang mit den Auenlebensräumen im Bezugsraum langfristig auf die klimainduzierten Rahmenbedingungen eingestellt und zu einem klimaangepassten integrierten „Flussauenmanagement“ weiterentwickelt werden kann, außerordentlich praxisrelevant und exemplarisch für komplexe Problemlagen im Umgang mit Kulturlandschaften.

Arbeitspaket hydro(geo)logische Folgen des Klimawandels

Die Untersuchungen im Labor- und Feldmaßstab werden durch numerische Simulationsmodelle für den Bodenwasserhaushalt ausgewertet. Auf diesem Wege werden die bodenhydraulischen Funktionen durch inverse Modellierung parametrisiert. Die dabei ermittelten van Genuchten Parameter werden zur bodenhydraulischen Charakterisierung der Standortgegebenheiten benutzt. Es werden anschließend numerische Prognosen des Bodenwasserhaushalts unter den veränderten Klimabedingungen durchgeführt. Für die veränderten Klimabedingungen werden Szenarien entwickelt, die auf bestehenden Klimaprojektionen basieren. Anhand dieser Szenarien kann unabhängig von zur Zeit vorhandenen Projektionen der Einfluss des Klimawandels in größerem Ausmaß untersucht werden.

  • Das Modell Wehninger Werder ist weitestgehend kalibriert, Modelläufe und erste Auswertungen des Referenzzeitraums sind erfolgt
  • Erste Modellläufe mit Klimaszenarien wurden durchgeführt





Materials in contact with drinking water and preventive measures for new building distribution systems

Materialien in Kontakt mit Trinkwasser und Präventivmaßnahmen für neue Gebäudeverteilsysteme


  • Eawag, Dübendorf, CH
  • Geberit International AG, Jona, CH
  • Georg Fischer JRG AG, Sissach, CH
  • Industrielle Werke Basel / Wasserlabor, Basel, CH
  • Wasserversorgung Zürich, Zürich, CH
  • Kantonales Labor Zürich (KLZH)
  • Hochschule Luzern (HSLU)/Zentrum für Integrale Gebäudetechnologie (ZIG)
  • SVGW Schweizerischer Verein für Gas und Wasser (SVGW)
Finanzierung: Kommission für Technologie und Innovation KTI, Bern, CH
Laufzeit: Januar 2014 - Dezember 2016

Projektleitung / Projektbearbeitung:

Projektleitung (Eawag):
Dipl.-Ing. Stefan Kötzsch, Dr. Frederik Hammes

Projektbearbeitung (Eawag):
Franziska Rölli, Romina Sigrist

Projektkommission/-bearbeitung (DVGW-TUHH):
Dr. Bernd Bendinger / Dorota Bruniecka-Sulewski


In häuslichen Trinkwasser-Installationen können Werkstoffe aus Kunststoff einen erheblichen Einfluss auf die chemische und mikrobiologische Trinkwasserbeschaffenheit ausüben. Mittels des Methodenpakets „BioMig“, sollen Hersteller ihre Kunststoffprodukte für den Einsatz im Trinkwasserbereich effektiver optimieren können und der Endverbraucher soll durch Produktvergleiche eine bessere Orientierungshilfe über Produktqualitäten erhalten. Zusätzlich sollen geeignete Präventivmaßnahmen bei der Inbetriebnahme der Trinkwasser-Installationen den Endverbrauchern mehr Sicherheit bieten.


Vorgehensweise: Teil 1: Bewertung von Werkstoffen in Kontakt mit Trinkwasser und Möglichkeit zur Produktoptimierung für Hersteller

Das Methodenpaket „BioMig“ ermöglicht die Bewertung von Kunststoffen mit hoher Reproduzierbarkeit innerhalb von 14 Tagen. Dabei wird zum einen die Migration von organischem Kohlenstoff ins Wasser und dessen biologische Verwertbarkeit bestimmt. Zum anderen werden das Biofilmbildungspotenzial auf der Oberfläche des Werkstoffes und das Wachstum von Bakterien in der Wasserphase des Testwassers bestimmt.

Im Rahmen von Ringversuchen wird die Reproduzierbarkeit von Ergebnissen zwischen verschiedenen Laboren ermittelt.

Teil 2: Entwicklung, Prüfung und Etablierung von geeigneten Präventiv- und Langzeitmaßnahmen zur Verbesserung der hygienischen Situation in Trinkwasser-Installationen anhand von Prüfständen

An zwei Standorten mit unterschiedlichen Wasserbeschaffenheiten werden drei verschiedene praxisnahe Testsysteme zur Beantwortung verschiedener Fragestellungen betrieben.

Testsystem I: Welche Auswirkungen haben Präventivspülung, Hygienefilter und Desinfektion mit Chlor auf die Elimination von hygienisch relevanten Bakterien aus der Trinkwasser-Installation?

Es werden an beiden Standorten jeweils drei Prüfstände mit Trinkwasserleitungen und Verbindungsstücken aufgebaut. Jeder Prüfstand enthält wiederum jeweils drei Installationen aus verschiedenen Kunststoffen (PE-Xb, PE-Xc, PB). Zur Simulation einer Druckwasserbeprobung mit kontaminiertem Wasser werden Escherichia coli K12 und Pseudomonas fluorescens P 17 in das Befüllwasser gegeben.

Testsystem II: Wie entwickelt sich die mikrobiologische und chemische Wasserbeschaffenheit in Trinkwasserleitungen in Abhängigkeit von Werkstoff, Temperatur, und Trinkwasserbeschaffenheit?

Für fünf verschiedene Kunststoffe (PE-Xa, PE-Xb, PE-Xc, PE-RT, nicht für den Trinkwasserbereich zertifiziertes PE-Xc) werden in 9 m langen Leitungen mit praxisnahem Durchfluss- und Stagnationsprogramm unter Kalt- und Warmwasserbedingungen die Gesamtzellzahlen im Biofilm und in der Wasserphase untersucht. Zusätzlich werden der gesamte organische Kohlenstoff (engl. TOC) und seine biologische Verwertbarkeit bestimmt. Populationsanalysen werden für die Bakterien in der Wasserphase und im Biofilm durchgeführt.

Testsystem III: Kann eine automatischen Spüleinrichtung oder eine kontinuierliche Trinkwasser-Chlorung eine Verkeimungsquelle in der Trinkwasserleitung beseitigen?

In einer Metallleitung, die einen „Hot spot“ der Zellabgabe enthält, werden die Gesamtzellzahlen im Trinkwasser bei Einsatz der Präventivmaßnahmen untersucht. Außerdem sollen anhand des Testsystems u.a. Probenahmestrategien zur Lokalisation von Kotaminationsquellen entwickelt werden.

Teil 3: Untersuchung von neuen Trinkwasser-Installationen.

In realen Trinkwasser-Installationen, die neu in Betrieb genommen werden, sollen mikrobiologische Daten erhoben werden. Zusätzlich werden Beprobungsstrategien für komplexe Gebäudeinstallationen entwickelt. Wenn sich die Gelegenheit bietet, werden auch Neubauten mit bekannten hygienischen Problemen beprobt.



Ergebnisse: Das BioMig-Verfahren ermöglicht eine hohe Reproduzierbarkeit von Ergebnissen zur Bewertung von Kunststoffen in Kontakt mit Wasser. Mit dem Methodenpaket können verschiedene Effekte von Kunststoffen auf das Wasser erkannt werden.
  • Biologische Abbaubarkeit der migrierten organischen Kohlenstoffverbindungen
  • Inhibierung des mikrobiologischen Wachstums
  • Temperaturabhängigkeit der Migration von organischen Kohlenstoffverbindungen
  • Mikrobiologisch induzierte Migration von organischen Kohlenstoffverbindungen
Projekthomepage: keine



LbL-modification of UF-capillary membranes

LbL-modification of UF-capillary membranes

Funding: TUHH
Duration: 01.02.2017 – 31.01.2017

project management / project work:

Prof. Dr.-Ing. M. Ernst / S. Dillmann, M.Sc.


Commercial ultrafiltration membranes with a pore diameter of 10-20 nm are not suitable for the removal of dissolved water compounds. The layer-by-layer (LbL) technique is a possibility for the modification of these membranes to reach adequate rejection of substances like sulphate, hardness or dissolved organic compounds. The removal of these substances is currently realised by energy-intensive or environmentally critical processes like nanofiltration, reverse osmosis or ion exchange.
The process conditions of the LbL-modification have a great impact on the resulting membrane. Parameters as the number of double layers, the molecular weight of the polyelectrolytes, temperature, pressure, pH value or ionic strength during the coating influence the properties of the coated membrane.



The aim of this project is the determination of the process conditions during the LbL-coating of an UF-capillary membrane and the optimization of the separation properties of the resulting membrane. A laboratory filtration unit is used for the investigation of the permeability and rejection, as well as the inquiry of the stability of the coating and the backwash behaviour. Electron microscopy and the measurement of the zeta potential provide additional information about the coating structure.

Recent project results: Download




Methane in groundwater treatment: characterisation of methanotrophic bacterial populations in drinking water treatment plants with molecular biological methods
Duration:01.04.2014 - 30.06.2017

project management / project work:

Dr. B. Bendinger /  Julia Schmitt, M. Sc.


Although methane is widespread in anaerobic groundwater, it is not routinely considered as a relevant parameter in drinking water production. After oxygenation, methane can affect the treatment negatively since it promotes the growth of aerobic methane oxidizing bacteria (MOB). Especially in rapid sand filters (RSF) biomass and metabolic activity of MOB can cause diverse treatment problems like incomplete manganese and ammonium removal, biofilm formation as well as hygienic and filterhydraulic problems. Since a deduction of MOB biomass from raw water methane concentration is not possible, the characterization of MOB is obligatory to identify them as a (contributing) cause for treatment difficulties.


Methodology:In the project, a multi-parameter approach is applied for the characterization of MOB in filter material samples from water works treating methane-containing groundwater. The approach combines relative and absolute quantification of MOB by fluorescence in situ hybridization (FISH) and quantitative PCR (qPCR). The quantitative analyses are complemented by batch activity tests for measurement of the methane oxidation potential as well as 16S rRNA amplicon sequencing for MOB diversity analysis. The combined application of the methods allows the investigation of the effect of different influence factors like raw water quality and operation conditions on MOB quantity, diversity and activity in RSF and represents the basis to evaluate the relevance of MOB with respect to observed treatment problems.



Fouling of low-pressure membranes during water treatment: causes, analysis and strategies for reduction
Duration:01.10.2012 – 30.09.2016

project management / project work:

Prof. Dr.-Ing. M. Ernst / Dipl.-Ing. Martin Schulz


Low-pressure membrane techniques in water treatment, like microfiltration (MF) and ultrafiltration (UF) offer many advantages compared to conventional purification processes due to a small footprint, reliability in operation and high water quality effluent independent of the available raw water source. One of the main limitations of UF and MF systems is membrane fouling, which is the undesirable deposition and accumulation of particulate matter, microorganism, colloids, and solutes on and within the membrane matrix. Fouling is undesirable because it reduces membrane performance, increases operating costs, and shortens membrane lifetime.

The objectives of this project are to estimate the impact of different water constituents on the fouling layer formation during the filtration process by analyzing the composition of the feed water, to identify new analytical approaches to predict the fouling potential of varying raw water sources and, based on this, to develop suitable and sustainable strategies to stabilize the filtration process.



Lab-scale as well as pilot-scale systems are available for filtration and fouling experiments. The dissolved fraction of natural organic matter is quantified and characterized by methods of the analytic chemistry, like the Liquid Chromatography with Organic Carbon Detection (LC-OCD) and the Fluorescence Spectroscopy (EEM). Image analysis techniques like the Nanoparticle-Tracking-Analysis (NTA) are used to investigate the colloidal and particulate water constituents. A promising option to enhance this technique is the application of fluorescence marker for a further discrimination of specific colloidal groups. The impact of individual water constituents, as well as their complex interactions, on the membrane filtration behavior is investigated by tests with model waters. The results are verified by and critically compared to filtration performance with real waters of varying raw water sources. Using a statistical data analysis, fouling relevant substances shall be identified and – depending on the water composition – be reduced by means of different pre-treatment strategies (e.g. coagulation, adsorption or oxidation) in order to identify conditions, which allow an energy and cost efficient application of this technique.



Safe and reliable water systems for peri-urban, decentralized and rural areas: Integrating local needs, innovative materials and production methods to ensure safe water provision


Safe and reliable water systems for peri-urban, decentralized and rural areas: Integrating local needs, innovative materials and production methods to ensure safe water provision



Duration:01.06.2017 – 31.05.2018

project management / project work:

Prof. Dr.-Ing. M. Ernst / J. Benecke, M. Langer


The German Federal Ministry of Education and Research (BMBF) promotes the development of international research cooperation within the funding programme "International Cooperation in Education and Research – The Central, Eastern and South Eastern European Region" (Moel-Soel).

Together with partners from Greece and Poland, sustainable concepts for safe water supply will be developed to meet local challenges. The main objective of the SafeWatPRO project is the preparation of a successful proposal and application for the for  funding  of  the  EU  Framework  Programme  for Research  and  Innovation  Horizon  2020  and  other  research-relevant EU  programmes.


The main focus is on the development of a sustainable concept based on the application of new materials and energy efficient technologies for drinking water supply. For the submission of an H2020 proposal innovative water treatment processes are developed.



DVGW-Projekt: Innovations-Scouting Wasser

DVGW-Innovations-Scouting Water


Duration: 01.09.2019 – 31.08.2022
Project partner: Coordinated by TZW: DVGW-Technologiezentrum Wasser
IWW Water Centre
DVGW Research Centre TUHH
DVGW Research Centre Engler Bunte Institute at KIT

Project management / project work:

Prof. Mathias Ernst, Dr.-Ing. Barbara Wendler


Increasingly, water supply companies wish to capture and assess modern technology developments incorporating the international water market to resolve specific forthcoming challenges. Assessing technologies requires a neutral and technically competent screening of technology providers on the global market, including identifying the advantages and disadvantages for application under the conditions for water supply companies in Germany.

Methodology: The project identifies modern technical solutions on the national and international water market for specific forthcoming challenges faced by water suppliers. This is achieved with interviews and workshops with water suppliers based on scouting for innovations across disciplines. Together, DVGW Research Centre TUHH and DVGW Research Centre Engler Bunte Institute perform a trend study including evaluation of research activities to detect future trends in drinking water supply. The results of this scouting are also used to update the 2025 DVGW research strategy.
Project page:
Recent project results: Download



Selective Oxy-anion Removal from Drinking Waters by modified Hollow Fiber Membranes

Selective Oxy-anion Removal from Drinking Waters by modified Hollow Fiber Membranes


i³ Projekt der TU Hamburg
Duration: 01.01.2020 – 30.06.2022
Project partner: Helmholtz-Zentrum-Geesthacht – Institute for Polymer Research / Dr. Volkan Filiz

Project management / project work:

Prof. Dr.-Ing. M. Ernst / Tomi Mantel, M. Sc.


In 2020, 30% of the world population had no access to safe and clean drinking water supply. Some of the rreasons for this are microbiological pollution and the presence of arsenate and other heavy metals in raw water sources. High concentration of arsenate in ground water is a health problem for more than 300 million people in 100 countries in the world. Related to arsenate, chromate is another geogene pollutant that causes problems for the water supply of millions people worldwide. Both substances belong to the chemical group of the oxyanions (HAsO42-, CrO42-) and are highly carcinogenic and listed as most hazardous health issues by the WHO (World Heath Organization). Due the negative charge of this substances, ion exchange is a possible technology of the treatment of this raw water. However, this technology is technically complicated as well as cost and energy intensive.

Methodology: Goal of this project is the development of a new ultrafiltration membrane which is capable of rejecting microbiological pollutants as well as remove oxyanions by adsorption onto the membrane material. For this, the Institute for Water Resources and Water Supply (TUHH) and the Institute for Polymer Research (HZG) will collaborate interdisciplinary to develop a functionalized polymer membrane. The novel membrane should be able to remove particular substances due its small pore size (10-30 nm) and operate at moderate pressures of max. 0.3 bar. The membrane will be modified with anion exchange groups to create a selective adsorption capacity for arsenate and chromate ions. Due to a periodic backwash, particular fouling will be removed and anion exchange groups will be regenerated. By this technology, only a single filtration is necessary to produce microbiologically safe and oxyanion-free drinking water.
Recent project results: Download



BMWi-cooperation project: Treatment of groundwater with increased sulfate concentration: innovative options and limits of resource and energy efficient drinking water management

BMWi-cooperation project: Treatment of groundwater with increased sulfate concentration: innovative options and limits of resource and energy efficient drinking water management (SULEMAN)

Funding: BMWi und DVGW
Duration: 01.06.2018 - 28.02.2022
Project partner: DVGW-Forschungsstelle TUHH
Hamburger Wasserwerke GmbH
Berliner Wasserbetriebe AöR
KompetenzZentrum Wasser Berlin gGmbH
Surflay Nanotec GmbH

Projectmanagemanet / project work:

Dr.-Ing. Barbara Wendler, Jakob Stumme


Water suppliers have to deal with increasing sulfate concentrations in ground water and bank filtrate used for drinking water production. There are several reasons for the increase of sulfate concentration.

  • Shut-down and flooding of open brown coal pits cause increased sulfate concentration in surface water. From the surface water, sulfate can migrate into near-surface groundwater that is used for drinking water production
  • Increasing concentrations of nitrate and the related oxidation of pyrite in pyrite dominated extraction sites result in oxidation of sulfide to sulfate with consequential effects on the ground water quality
  • Deep groundwaters, as present in northern German extraction sites, are partially in exchange with salt domes (especially gypsum) and therefore enrich sulfate  

The limit value for sulfate in drinking water is at 250 mg/L as prescribed in the German Drinking Water Regulation and must be strictly adhered by all drinking water suppliers.


Within the project commercially available technologies (low pressure reverse osmosis LPRO, ion exchange process CARIX) are tested regarding energetically optimized, sustainable sulfate removal for the treatment of different raw waters for drinking water application.  In Hamburg, deep and salty ground waters (anaerobic before and aerobic after deferrization) are tested, in Berlin near-surface bank filtrate is treated.

Results from semi-technical scale (plant capacities ca. 1 m³/h) are extrapolated regarding available literature data and are compared through ecological (life cycle assessment) and economical assessment. Evaluation criteria are amongst others specific energy consumption, application behavior and sustainability of each technology under varying raw water compositions.

Beyond the industrially available technologies LPRO and CARIX a commercial Polymer-UF-Membrane is post modified by a novel coating process and thus optimized for the target substance sulfate. This innovative technology of Capillary-NF runs at low operating pressures compared to the state of the art processes and will therefore be able to realize operation at  lower energy demand for the treatment of waters with increased sulfate concentration. The experiments are run in parallel to the LPRO and CARIX trials in technical scale. The operation data of the Capillary-NF are regarded in the ecological assessment and are critically compared with results of LPRO and CARIX.

Project page: SULEMAN
Other project pages:

Recent project results: Download


Influence of surface potential of conductive polymer membranes (ZETA-Membrane) on the fouling- and separation behavior in water treatment

Influence of surface potential of conductive polymer membranes (ZETA-Membrane) on the fouling- and separation behavior in water treatment

Funding: DFG
Duration: 01.01.2015 - 30.06.2020

project management / project work:

Prof. Dr.-Ing. M. Ernst / Tomi Mantel, M. Sc.


The usage of membrane filtration in water treatment was rapidly increasing in the last 20 years. Despite of the rising number of applications of commercial membranes, the main drawbacks in this technology remain the formation of fouling layers. In low pressure membrane processes (micro- and ultrafiltration), mainly particles, colloids, organic macro molecule (organic fouling) and microorganisms (biofouling) lead to the formation of these layers. High pressure membrane processes like nanofiltration, are mainly affected by the adsorption of organic substances and biofouling. Measures for the reduction of fouling are ranging from the pre processing of incoming water, through the improvement of fluid dynamics within the membrane module to the physico-chemical modification of surface properties of the used materials (mainly polymers). In latter field, the present research project wants to investigate unresolved questions regarding the relationship between surface charge and resulting fouling and separation behavior.



Using ion beam enhanced deposition of metals, called plasma immersion ion implantation and deposition (PBII&D), the surface conductivity of common polymer membranes will be increased. By applying an external potential (-1.5 V to 1,5 V), these modified membranes will be examined on their fouling- and separation behavior in different aqueous solutions.  The results will be compared with existing transport models (electrokinetic models) and they will be adjusted, if necessary. These findings will be used to design a model which can be used for the simulation of the separation behavior under different operation conditions. More detailed and comprehensive understanding of the interactions between surface charge of the membrane (zeta potential) and resulting fouling- and separation behavior can be utilized for “potentially controlled functionalization” of membrane surfaces.

Recent project results: Download