1990-3

The demand for more efficient wastewater treatment in Sweden and Denmark has increased lately. The demand for nitrogen removal has especially increased in Sweden, where this means that nitrogen has to be removed with 50 % to begin with and 75 % for some areas later on. In Denmark the general requirement is a maximum […]

The southern part of Halland in south-west Sweden constitutes an area with great risk for nitrogen leakage from agricultural land. This is due to high precipitation, sandy soils and intense animal and crop production. The nitrogen transport in the agricultural rivers Trönningeån and Smedjeån is high but has decreased significantly during the 1980s. Decreasing transport […]

In a fish tank with a build-in upstreams aerobic biological filter (The BIOFISH System), batch-experiments were made to study whether hydrolysis of urea is a limiting step in the conversion of urea to nitrate. Based on frequent grab sampling and analysis of the different forms of nitrogen in the water, calculations were made for the […]

The introduction of biological nitrogen removal at many sewage treatment plants in Sweden, particularly those located at coastal regions up to Stockholm archipelagio in the east, is now proceeding primarily by plant trial operation. The deficit of an easily biodegradable carbon source for anoxic denitrification and the cold winter climate are the most characteristic problems […]