Water analysis Conducting and evaluating physical-chemical and microbiological water testing in accordance with the German Drinking Water Ordinance and other relevant legal regulations.
Testing of products and devices Initial testing of products and materials in contact with drinking water. Our Test Centre is accredited for more than 200 different product standards according to DIN EN ISO 17025. Test and develop UV technology.
Treatment technologies Develop sustainable water supply concepts. Implement, monitor and optimise new technologies. Test and further develop existing treatment methods.
Micropollutants and microorganisms Develop and improve the method of determination using cutting-edge equipment. Investigate the presence, behaviour and retention of inorganic and organic micropollutants in the water cycle and drinking water treatment.
Networks and drinking water distribution Microbiological quality change, deposit formation and cleaning and optimisation of the distribution network operation. Evaluate and analyse corrosion damage.
Risk management Support for water supply companies to establish a Water Safety Plan. Benefit from our extensive expertise.
Contaminated sites Evaluation of the decomposition potential at contaminated locations. Development of sustainable ways to eliminate pollutants from the environment. Employ a combination of microbiological and technical methods.
- About TZW
Providing drinking water of highest quality at the tap is one of the primary goals of water supply. This places high requirements on the drinking water network operator. Despite all efforts, it is not possible to entirely exclude variations in quality during water distribution. Targeted measures need to be taken to control and eliminate abnormalities. These measures frequently require detailed knowledge of the complex processes involved in the distribution system. TZW works hard to clarify these processes using specialist methods of analysis and concepts. We offer water supply companies consultation on all aspects of drinking water quality assurance in the distribution system and support them in the development of specific network management strategies.
Pitting corrosion and perforations in galvanised steel, copper and stainless steel can cause damage to water supply systems. We have in-depth technical expertise on this subject and offer comprehensive damage investigations.
Condition-based flushing of drinking water networks
Brown or turbid water is a frequent quality issue in drinking water distribution and is caused by the mobilisation of deposits in the pipes. TZW has developed the concept of condition-based network flushing. This is based on flushing individual network sections once deposit build-up has reached a critical potential. TZW offers its support for the implementation of a condition-based flushing strategy. This includes developing flushing schedules, conducting, evaluating and scientifically assessing the flushing processes as well as defining tailored flushing intervals and districts.
Assessment of corrosion inhibitors
Corrosion inhibitors are primarily used in water distribution with the aim of avoiding rusty water. Continuous turbidity measures are ideal for assessing the need to add inhibitors or to optimise the inhibitor composition as well as the additive quantity under the specific distribution system conditions. The corrosion behaviour of the pipe materials in the network can be evaluated in detail using turbidity curves. TZW defines the representative measurement points, provides the measuring instruments and prepares recommendations on inhibitor use after evaluating the turbidity curves.
Identification of microbiological contamination points
In practice, routine testing is frequently revealing isolated findings of coliform bacteria or enterococci. Findings may relate to an indicator for latent pollution or for a sporadic contamination. TZW established the following approaches to quickly and clearly identify contamination points, which have been tried and tested in a range of cases in practice:
- Microbiological sampling in conjunction with systematic flushing to check colonisation in the network.
- On-site enrichment of bacteria using the MikroSens filtration system, developed by TZW, to increase test sensitivity.
- Molecular biological identification to assess hygienic relevance
Anomalies caused by invertebrates can also arise in water distribution. Using a filtration system developed by TZW, invertebrates are enriched as part of network irrigation and these are then quantified and identified in the lab. As part of a systematic procedure, the exact population density per pipe section is determined and corrective measures are devised and/or evaluated.
Multicriteria data analysis
Extensive data series are generated by studies and sensors in water treatment and distribution. A multicriteria assessment of time series can analyse links, detect anomalies and identify optimisation potentials. TZW has developed algorithms, for example, to predict water requirements in the short term or to detect events. The analyses provide an important basis for optimising the system and network management.
Cause analysis for corrosion damage
Corrosion damage negatively impacts water quality and in the worst case it may cause water leaks. These issues often cause consequential damage to buildings. In addition to a thorough survey taking into account all associated aspects, we conduct corrosion-chemical investigations and cut materials which help to determine the type and cause of damage for the most diverse metallic and non-metallic materials.
Methods and equipment
- Utility vehicles with flushing device to record the deposit situation and flushing speed
- Mobile online turbidity measuring devices for installation in the network
- TZW software “OptFlush” to calculate flushing intervals
- On-site bacteria enrichment systems “MikroSens”
- Molecular biological identification procedure
- Filtering system for enriching invertebrates
- Algorithms for time series analysis
Fourier transform infra-red spectrometer (ftir spectrometer)
Wricke, B.; Korth, A.; Richardt, S.: Minimierung sedimentbürtiger Gütebeeinträchtigungen durch modellgestützten Rohrnetzbetrieb. Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Minimisation of sediment-induced quality issues by means of model-based pipeline operation. Publications from TZW Karlsruhe]. Volume 48, (2010)
Korth, A., Donath, O.: Zustandsorientierte Spülstrategie für Trinkwassernetze [Condition-based flushing strategy for drinking water networks]. Energie- und Wasserpraxis, 11/2018, (2018), p. 38-41
Wricke, B., Korth, A.: Hygienische Sicherheit im Verteilungsnetz – Teil 2: Erkennen und Beseitigen der Ursachen mikrobiologischer Güteveränderungen [Hygienic safety in distribution networks – Part 2: identification and elimination of the causes of microbiological quality changes].. Energie- und Wasserpraxis 11/2016, (2016), p. 32-41
Korth, A. and Lohmann M.: Bewertung der Wirkung von Korrosionsinhibitoren im Verteilungsnetz
Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Assessment of the effect of corrosion inhibitors in distribution networks. Publications from TZW Karlsruhe]. Volume 82, (2018)
Hügler, M., Petzoldt, H., Korth, A.: Innovativer Ansatz zur Ursachenanalyse mikrobiologischer Belastungen. Veröffentlichungen aus dem Technologiezentrum Wasser Karlsruhe [Innovative approach for the cause analysis of microbiological pollution. Publications from TZW Karlsruhe]. Volume 70, (2015), p. 45-57
Volumes from the TZW publication series can be purchased here.
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