1994-4

The blue-green algal species, Anabaena, Aphanizomenon, Microcystis and Planktothrix, that usually dominates algal blooms, are the same species that produce neuroroxin and/or livertoxin. Furthermore, production of lipopolysacharide endotoxin by blue-green algae has been reported. The ecological significance of blue-green algal toxinproduction is unknown. Protection against phytoplankton consuming zooplankton or chemical warfare (in the competition for […]

This investigation is a result of a cooperation between the County Council, the Municipalities and the County Administration in the County ot Västerbotten, Sweden. The purpose was to study connections between mercury levels in northern pike (Esox Lucius) and environmental factors. Furthermore changes in time were investigated. A classification system, which can be used to […]

If a high loaded activated sludge process is to be part of a process scheme for nutrient removal anaerobic digestion of the biological sludge has to be considered. However, even when plants are upgraded with a low loaded activated sludge process for nutrient removal anaerobic digestion may be of interest if the energy perspective is […]

Enhanced biologlcal phosphorus removal (EBPR) was studied at the Suomenoja research station in Finland in cooperation with St Petersburg Water and Wastewater Works. The studied process was a mainstream process designed for 10 m3 h-l wkh anaerobic and aerobic units. EBPR proved to be a stable and reliable method that endures organic volumemc loads up […]

Nitrification and denitrification in activated sludge process will be applied at Kungsängsverket in Uppsala municipality to fulfill future effluent requirements. In order to obtain total nitriflcation, a higher sludge retention time is required than in a conventional activated sludge plant. The highest sludge concentration that can be used is dependent on sludge separation properties and […]

Through a reconstruction during 1991 Oresundsverker i Helsingborg has been upgraded to a treatmentplant for extensive nitrogen and phosphorus removal. In order to run theese biological processes in the right way, it is important to know what parameters affecting the quality of the pretreated waste water. Furthermore it is important to understand the connection between […]