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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).

  • Daily field samples via flash tests

    Substance Threshold Expected value Minimum Maximum
    Nitrates 50mg/L 2,57 mg/L 1mg/L 3,5mg/L
    Lead 10µg/L 1,1 µg/L 0,5µg/L 2,5µg/L
    Phosphates 0,5 - 6,0mg/L 0,041 mg/L 0,03mg/L 0,17mg/L
    COD 1–2 mg/l 3,4 mg/L 2mg/L 7mg/L
    Ammonia nitrogen 1 mg/L 0,05 mg/L 0,05 mg/L 0,05 mg/L
    pH value 7-8,5 8,05 7,5 8,5
    Conductivity 500-1000µS/cm 792 µS/cm 500µS/cm 800µS/cm
    Temperature - - 04°C 24°C
    O2 content 7mg/L 11,3 mg/L 8mg/L 15mg/L

    What are the effects of the substances and parameters listed here?

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

    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.

    Phosphates: The overuse of phospate-rich fertilizers can lead to very high concentrations of phosphates in the soil. Leaching of land used intensively for agriculture can cause higher levels of phosphates in the groundwater and surface water. Increased levels of phosphates in drinking water, along with ammonium and nitrates, are a strong indication of possible pollution of water by faeces. 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 value: The pH value of water influences the metabolism of aquatic wildlife and the solubility of minerals. With a pH value it is possible to determine the main type of bonding in the water system.

    Conductivity: The electrical conductivity of water is an indicator of the concentration of dissolved salts and thus the level of pollution by soluble anorganic substances.

    Temperature: The oxygen saturation is directly linked to the water temperature. The higher the temperature, the less oxygen is dissolved in the water and the worse the living conditions for organisms in the water.

    O2 level: The oxygen level in the water is critical for micro-organisms and fish. At 20°C the maximum level allowable is 9.1 mg/l. This is dependent on the temperature and the concentration of dissolved salts. (See conductivity)

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

    • Microplastics (Furtwangen University)
    • Heavy metals (Perkin Elmer)
    • Pharmaceuticals/Hormones/Fertilizers (Perkin Elmer, Furtwangen University)
    • Fluorinated chemicals (TZW/Karlsruhe)
Rheines Wasser EN

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