2.5.2. Case Stories

2.5.2. Case Stories

1. Degassing and aeration plant for tap water

Technical information Trickling filter constructed in February 1997
Type BIO-BLOK® 80 HD G
Client Rødovre Vandværk (waterworks), Denmark
Consulting Engineers UNICON AQUA
Køgevej 172
DK-4000  Roskilde
Tel.: +45 46 34 60 00 / Fax: +45 46 34 61 08

Process diagram

Brief description of plant and process
The pumped raw water is lead to an existing raw water basin on which a trickling filter is established in the form of BIO-BLOK® 80 HD G placed horizontally. The raw water is spread over the trickling filter by means of a hole plate so that the contact surface of the water to the filter is as big as possible.

BIO-BLOK® 80 HD G has been chosen due to the fact that it is the filter medium that breaks the water best possible when the jets of water pass right through the net tubes. Thus the water gets a big contact with the oxygen of the air, and at the same time, the water is aerated most possible so that volatile gasses in the water can be aired effectively.

Treatment results
After the raw water has run through above mentioned aeration system, the water will be aerated to an aeration percentage of approx. 95%-100%. This results in the fact that iron and manganese etc. easily can be precipitated from the raw water in the subsequent filtration plant.

At the same time, the aeration plant causes that the raw water is degassed more effectively. In this case, the object is to air the chlorinated solvents such as Trichloroethane, Trichloroethylene and Tetrachloroethylene. These substances have been reduced considerably or completely removed.

Should you have any questions in connection with above, you are welcome to contact us and we hope that our material will give you and your colleagues inspiration as to how to enlarge or improve the waterworks in your area.