Plastic particles

Plastic particles instead of concrete - an alternative to building new tanks in sewage treatment plants

A number of Swiss domestic sewage treatment plants are being improved and expanded at present. A new treatment process from Norway (Kaldnes®) seems to promise increased purification performance without requiring new tank space. In collaboration with the association of sewage treatment plants of the region of Baden-Wettingen and the Swiss Federal Department of the Environment, Buwal, the engineering science department has been testing the suitability of the technique for the elimination of nitrogen.

The use of a moving bed biofilm system (MBBT) in municipal wastewater treatment was investigated in a pilot and full-scale plant. Energy demands, nitrification and denitrification capacity and typical operating conditions were investigated and compared with an activated sludge system and with the performance of an alternative carrier type.

It could be shown that this specific MBBT process with Kaldnes® biofilm carriers is a valuable alternative to activated sludge systems.

The report in German can be ordered from the Federal Office for the Environment:

Maurer M., Fux C. und Siegrist H. 1999. Nitrifikation und Denitrifikation im Wirbelbett – Biologische Reinigungsleistung in der kommunalen Abwasserreinigung. Mitteilungen zum Gewässerschutz No 36, Bestellnummer: MSG-36-D. BUWAL, Bern.

(Nitrification and denitrification in moving bed biological treatment of municipal wastewater, Swiss Agency for the Environment, Forests and Landscape, Bern)

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