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Experiments and analyses

Testing the performance of different VF CWs

We carried out the study at a test facility in the village Langenreichenbach outside Leipzig in Germany. Wastewater from households in the village was cleaned in six VF CWs, all designed and operated in different ways.

The six VF CWs at the test facility in Langenreichenbach
The experimental setup. Wastewater from households was pre-treated in a septic tank and then distributed to each VF CW where further cleaning took place. The plant species used in the planted VF CWs was Phragmites australis (common reed).
A fresh wastewater sample, just collected from the inside of a VF CW.

We took wastewater samples from each VF CW every 2-3 weeks during five months. The samples were taken from five different depths inside the VF CWs:

0 cm (inlet)

10 cm

20 cm

40 cm

80 cm (outlet)

Laboratory analyses

In the laboratory, we analyzed the content of organic material, nitrogen and E. coli bacteria in the wastewater samples. Then we compared the cleaning performance among the different VF CWs and also studied how much pollutants were removed at different depths inside the VF CWs. The results can be found under "Findings and conclusions" in the left menue.

Ongoing lab analysis of E. coli. The wastewater samples were first appropriately diluted and then incubated in a nutrient solution. After 16 hours it was possible to count the amount of E. coli with the help of a UV-lamp (the glowing blue squares contained E. coli).
Ongoing lab analysis of Biochemical Oxygen Demand (BOD) over 5 days, which is a measure of the amount of organic material in the wastewater. The yellow caps register the amount of oxygen used by the microorganisms that eat organic material. This makes it possible to estimate how much organic material was in the wastewater in the first place.


Responsible for this page: Director of undergraduate studies Biology
Last updated: 05/22/11