KVÄVEREDUKTION VID AVLOPPSVERKET SLOTTSHAGEN I NORRKÖPING, Nitrogen Removal at the Sewage Treatment Plant Slottshagen in Norrköping
Attempts to reduce the nitrogen content in wastewater at the sewage treatment plant Slottshagen in Norrköping have been accomplished during 1987. The plant, which takes care of the sewage from about 100,000 persons, was built for sedimentation, biological purification with activated sludge and chemical purification through post-precipitation in a separate step. After conversion of the […]
WATER POLLUTION IN DENMARK A REVIEW WITH SPECIAL REFERENCE TO FRESHWATER RESOURCES
Most Danish lakes and rivers are seriously eutrophicated and still greater areas of the coastal waters show oxygen depletion in the bottom layers during summer periods. Nitrogen washout from farmland and nitrogen, phosphorus and organic matter originating from domestic and industrial sewage, both contribute to increased phytoplankton and periphyton production and oxygen demands for decomposition. […]
AN AUTOMATED METHOD FOR THE DETERMINATION OF STRONG AND WEAK ACIDS IN FRESHWATER
The Gran procedure described by Molv©¡rsmyr and Lund (1983) was modified and automated for the routine analysis of strong and weak acids in freshwater. The titrations are carried out by coulometric generation of hydroxide ions in the pH range 3.6-10.3. The method measures the amount of non-volatile strong and weak acids in freshwater with a […]
ENERGY BUDGET OF CAGED COMMON MUSSELS (Mytilus edulis) IN THE VICINITY OF AN INDUSTRIAL CENTRE ON THE SWEDISH WEST COAST
The Askerö fjord receives wastewater from petrochemical industries located in Stenungsund on the Swedish west coast. During the autumn of 1987 an investigation was performed where the physiological status of common mussels (Mytilus edulis) which had been caged in this area was studied. The measured physiological parameters were: feeding rate, absorption efficiency, respiration and ammonia […]
VATTENFÖRBRUKNING OCH BEVATTNINGSBEHOV VID ENERGISKOGSODLING I GÖTALAND OCH SVEALAND / Water Use and Irrigation Need for Willow Forestry in Southern Sweden
Introduction of energy forestry in Sweden is likely to occur in the beginning of the 1990’s. To describe how an intensively cultivated willow forestry might affect the water resources and what the irrigation need might be, the evaporation and water balance were simulated by a reasonably simple, yet physically realistic model. Average evaporation during the […]
FUNKTION OCH STABILITET I SÖTVATTENSMODELLEKOSYSTEM / Function and Stability of Freshwater Model Ecosystems
Function and stability of five freshwater model ecosystems were studied during three months in 1985. Two of the models had no fish and the other three had fishpopulations of different kinds. The ecosystems intended to be models of a Lobelia/Isoetes-community in the oligotrophic lake Nedre Fryken. Most of the material for the model ecosystems was […]
KVÄVE OCH FOSFOR SOM BIOMASSABEGRÄNSANDE ÄMNEN I HAVET / Nitrogen and Phosphorus as Growth Limiting Substances in the Sea
The controversy whether nitrogen or phosphorus limits phytoplankton growth in Swedish coastal and sea areas has been ongoing since the early 1970’s. Today there is a consensus among scientists that nitrogen is the key factor controlling phytoplankton growth in the Baltic proper, Kattegat and Skagerrak and phosphorus in the Bothnian Bay, while the Bothnian Sea […]
KVÄVE ELLER FOSFOR – VAD ÄR BEGRÄNSANDE NÄRSALT I KUSTOMRÅDEN? EXEMPEL FRÅN NORSKA FJORDAR / Nitrogen or Phosphorus – what is Limiting Nutrient in Coastal Areas? Examples from Norwegian Fjords
The dominating role of phosphorus as limiting nutrient in fresh water is well documented, while the situation in coastal areas and the open sea is less clear. In the marine environment phosphorus (P) and nitrogen (N) availability appears to be more balanced to the nutrient requirements of algae. When nutrient limitation is discussed, it is […]
NITRIFICATION WITH IMMERSION PERCOLATING FILTERS – Wider uses for new technologies even in large sewage works
New process technologies have considerably improved the specific nitrification capacity per unit area of immersion percolating filters. The operating principle is based on strict separation of the carbon reduction and nitrification processes together with uniform substratum supplies in cascade plants. These processes lake the immersion percolating filter viable even for high capacity plants. The method […]
KVÄVEREDUKTION I ETT BASSÄNGREAKTORSYSTEM / Nitrogen Removal in a Suspended Growth System
The intention with the trial operation at the sewage treatment plant Västra Stranden, Halmstad was to investigate what the nitrogen removal would be during summer conditions after extension of the tanks for anoxic pre-denitrification to the double. The flow to the three separate activated sludge units was distributed in such a way that two of […]