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  • On-the-spot Analysis of Water Samples

    Rapid tests deliver immediate results

    A portable photometer and test kits provided by MACHEREY-NAGEL enable the project team to analyze sample content on-site. Our scientists will be testing for turbidity, chemical oxygen demand (COD) values, total organic carbon (TOC) values, and levels of ammonium, oxygen, nitrates, and phosphates. With these values, variations in concentrations along the Tennessee River can quickly be identified.


    Filter Analysis in Labs

    Searching for the component parts

    Every day, a specified amount of water will be filtered with a special filter system from Wolftechnik Filtersysteme GmbH & Co. KG. The filter cake will be stored and at the end of the project tested under an infrared microscope to determine microplastics type and particle size distribution. The sampling process, as well as the testing and evaluation of the samples, will be supported and carried out by Furtwangen University.

    Furtwangen University Wolftechnik

    How Even the Smallest Particles Become Visible

    Modern measurement methods in use

    During the swimming phase a portable ATR-IR spectrometer provided by Perkin Elmer will be used to test visible plastic particles on-the-spot. Visitors can give it a try, too if they are interested. Invisible particles which are < 6 µm in size will be examined at HFU with a Perkin Elmer infrared microscope.


    The Passive Sampler

    Like a fish – constantly in contact with water

    With a so-called passive sampler the swimmer collects all adsorbable materials which he comes into contact with in the Tennessee River. The sampler is a membrane placed on the swimmer’s leg or back. At the end of the swim stage the contents of the sampler are extracted at EAWAG and carefully tested for multiple water-soluble organic chemicals. Using this method, several hundred known substances can be determined. An unknown substance analysis can also be done on any particularly intensive residual substance peaks in order to find any until-now undiscovered chemicals and possibly identify them with the help of high-resolution mass spectrometry.

  • What happens to the water samples?

    Analyses on site and in the lab

    Every day that Andreas Fath swims the Tennessee River, water samples will be taken by the team. They will be tested for multiple parameters including redox potential, pH value, conductivity, temperature and dissolved oxygen. Additionally, the quantity of microplastics will be analyzed by random sampling.

    Some of the measurements can be evaluated on site. More complex tests will be carried out in the labs of Furtwangen University and those of their "Tenneswim" project partners (for example, the testing for heavy metals such as lead, arsenic, nickel, chrome and cadmium).


    The Tennessee River – one big sewer?

    A lot of waste is washed into the river

    Fluorinated industrial chemicals (such as PFOS and PFOA) taken from the daily samples will be analyzed using a normed process at the Water Technology Centre in Karlsruhe. Softeners (such as Diisisononylphthalat) from the daily samples will be analyzed at HFU at the end of the swimming phase of the project.

    Technologiezentrum Wasser

    From drugs to artificial sweeteners

    What substances are there in the Tennessee River?

    Samples taken constantly via a microfabric that is attached to the swimmer will be analyzed for over 600 different substances. These include pesticides and biocides (such as Isoproturon, Diuron, and DEET), drugs (such as codeine, methadone, and amphetamines), pharmaceuticals (such as antibiotics, painkillers, betablockers, and antidepressants), artificial sweeteners (such as cyclamate and saccharine) and corrosion inhibitors (such as benzotriazole).

  • Analysis of daily field samples via quick tests

    Tennessee River
    Minimal Maximal
    Nitrat unter 0,3mg/L 0,95mg/L
    Phosphat unter 0.05mg/L 0,45mg/L
    CSB 5,5 mg/L über 40 mg/L
    pH-Wert 7,8 9,1
    Leitfähigkeit 144µS/cm 215µS/cm
    Temperatur 23,5°C 30,2°C
    O2-Gehalt 3,3 mg/L 7,9 mg/L
    Schwellenwert Erwartete Werte Minimal Maximal
    Nitrat 50 mg/L 2,57 mg/L 1 mg/L 3,5 mg/L
    Blei 10 µg/L 1,1 µg/L 0,5 µg/L 2,5 µg/L
    Phosphat 0,5 - 6,0 mg/L 0,041 mg/L 0,03 mg/L 0,17 mg/L
    CSB 1–2 mg/l 3,4 mg/L 2 mg/L 7 mg/L
    Ammonium-Stickstoff 1 mg/L 0,05 mg/L 0,05 mg/L 0,05 mg/L
    pH-Wert 7-8,5 8,05 7,5 8,5
    Leitfähigkeit 500-1000 µS/cm 792 µS/cm 500 µS/cm 800 µS/cm
    Temperatur - - 4°C 24°C
    O2 -Gehalt 7 mg/L 11,3 mg/L 8 mg/L 15 mg/L

    Why do we measure these parameters?

    Nitrate: Nitrate nitrogen usually results from vehicle emissions or from agricultural fertilizers. Large amounts of nitrogen, usually in the form of nitrates, can under neutral, aerobic conditions cause eutrophication, meaning that an overdose of nutrients leads to a lack of oxygen that causes fish to die (see DO).

    Lead: The heavy metal lead, in a constant concentration of more than 10µg/l, leads to chronic poisoning and hematopoietic stem cell defects. It also affects the metabolism of vitamin D and calcium and causes brain damage in infants.

    Phosphate: Increased levels of phosphate in water, along with ammonium and nitrate, could be an indication of possible pollution by feces or the overuse of phospate-rich fertilizers. Also linked to this is the unwanted or harmful growth of certain plants such as algae and the resulting ecological imbalance.

    COD: The chemical oxygen demand is, as a cumulative parameter, a measure of the total oxidable substances in the water under certain conditions. It defines the amount of oxygen (in mg/l) which would be necessary to cause oxidation, if oxygen were the means of oxidation. The COD is thus an indicator of the level of water pollution by oxidable organic substances.

    NH4 nitrogen: Ammonia nitrogen generally results from ammonia emissions from agriculture, animal husbandry in particular. Ammonia is not normally found in drinking or groundwater so if this occurs, it is a strong indicator of pollution through wastewater and landfill water seepage. By measuring ammonia levels, it is possible to determine the level of pollution and the quality of the water.

    pH: The pH value indicates whether a water body is acidic or basic. This parameter influences the metabolism of aquatic wildlife and the solubility of minerals. For instance, a low pH (which may be the result of acid rain or industrial effluents) increases the solubility and thus the toxicity of many heavy metals in water.

    Conductivity: Dissolved substances such as salts can increase water's capability to pass an electrical current. Increased conductivity therefore indicates pollution, resulting from storm water runoff or untreated wastewater; however, it can also result from natural sources such as soil erosion.

    Temperature: Water temperature is considered a water quality indicator, because thermal pollution (changes in water temperature that, for example, result from industrial cooling processes) can alter the existing species composition in natural water bodies.

    Dissolved Oxygen (DO): Oxygen dissolved in water is critical for aquatic organisms to survive. Oxygen-consuming bacteria (which increasingly occur when lots of organic matter decays) can cause whole water bodies to "die" since less oxygen is available to other organisms such as fish. This process is called "eutrophication".

    Substances that will be evaluated 4-10 weeks after termination of the project

    • Microplastics (Furtwangen University)
    • Heavy metals (Perkin Elmer)
    • Pharmaceuticals, hormones, and fertilizers (Perkin Elmer & Furtwangen University)
    • Fluorinated chemicals (Technologiezentrum Wasser)