PHOSPHORUS REMOVAL IN INTERMITTENT CYCLE EXTENDED AERATION ACTIVATED SLUDGE (ICEAS) SYSTEM
A large scale pilot treatment system has been used to study the effect of limiting the dissolved oxygen concentration in intermittent cycle extended aeration activated sludge (ICEAS) system on nutrient removal. The objective was to develop operating data and to establish and verify that operational conditions conductive to biological phosphorus removal can be maintained. It […]
KONTROLL AV SULFID-TOXICITET VID ANAEROB RENING AV INDUSTRIELLA PROCESSVATTEN / Control of Sulphide Toxicity in Anaerobic Treatment of Industrial Wastewater
Sulphide toxicity due to high concentrations of sulphurous compounds in some industrial wastewaters results in difficulties when using the favourable anaerobic treatment; it even makes anaerobic treatment impossible. Today, several methods are available for control of sulphide toxicity: heavy metal sulphide precipitation, addition of alkali to raise pH and thereby convert the toxic H2S to […]
MILJÖKONSEKVENSER VID ANVÄNDANDE AV DRÄNERANDE VÄGBELÄGGNING – EN LITTERATURSTUDIE / Environmental Influence from Using Porous Top Pavement – a Literature Study
Open black top pavement has advantages over usual black top in view of economics, accidental statistic and environmental factors. Noticed about the environmental advantages are lower load on waste water filtration plants, lowered risk for spillway overflow, less pollution to recipients, lowered noice levels for traffic and sustained ground water balance. The risk for clugging […]
MODELLSTUDIE AV METALLTRANSPORT GENOM EN SJÖ I ETT GRUVOMRÅDE / Modeling Metal Transport through a Lake in a Mining Area
Lakes have an important impact on element mass transport. The reduced velocity results in an increasing sedimentation and chemical and biological processes have time to influence the transport. Hydrochemical models can be helpful in the study of the importance of different processes. In this study we present simulated concentrations and mass transport of zinc, copper […]
WATER EXCHANGE AND DISPERSION MODELLING IN COASTAL REGIONS: A METHOD STUDY
A high resolution hydrodynamic model is used to estimate fluxes between boxes in a coarse compartment model. The latter model may include complex biogeochemical processes, here exemplified by dispersion of radionuclides released from a nuclear power plant. The water recipient – Öregrund Grepen – is assumed non-stratified and the circulation to be mainly winddriven. The […]
URBANHYDROLOGI I ETT EKOLOGISKT PERSPEKTIV / Urban Hydrology in Ecological Perspectives
A city is an alien element in natural ecological systems. All anthropogenic systems become monocultures with open material and energy systems. Overexploitation of natural resources (raw materials, water), or enrichment of residuals (pollutions) are the consequences. Today it is clear that urban areas must be kept in some kind of equilibrium which is acceptable for […]
TO ENTEROPATOGENE BAKTERIER SOM KAN OVERFØRES MED DRIKKEVANN I NORGE: YERSINIA ENTEROCOLITICA OG CAMPYLOBACTER JEJUNI/ CAMPYLOBACTER COLI / Two Enteropathogenic Bacteria which can be Transmitted with Drinking Water in Norway: Yersinia enterocolitica and Campylobacter jejuni/Campylobacter coli
Yersinia enterocolitica og Campylobacter jejuni/Campylobacter coli er to enteropatogene bakterier som kan overføres med drikkevann. Y. enterocolitica og Y. enterocolitica-lignende bakterier er vanlige overalt i vårt miljø, i dyr, vann og matvarer. Den medisinske betydning er knyttet til noen få serotyper, i Skandinavia særlig serotype 0:3. Svinekjøttprodukter regnes for å være den viktigste smittekilden. Y. […]
VIDEREGÅENDE RENSNING AF DRIKKEVAND – DENITRIFIKATION / Advanced Purification of Drinking Water – Denitrification
Water treatment in Denmark is generally based on unpolluted groundwater, where aeration and rapid sand filtration normally suffice. The growing threat of pollution has prompted the industry to investigate into advanced treatment processes. Some unpolluted groundwater resources are difficult to treat. Processes presently in use include stripping, chemical precipitation, biological nitrification, whereas chemical oxydation with […]
FJERNING AV HUMUS / Removal of Humic Substances
Due to aesthetical, organoleptic, health related as well as economical and practical reasons, humic substances constitutes a quality problem in drinking water. About 50 % of the Norwegian waterworks exceed the quality standards related to colour. A great effort has been made to find alternatives to the traditional way of humic substance removal, coagulation followed […]
THE IMPORTANCE OF ACIDIFICATION AND ACID GROUND WATER FOR WATER SUPPLIES
This paper deals with ground water acidification and its effect on water supplies in rural areas. The aim was to find solutions to problems caused by ground water acidity. Applications and methods still under development on neutralization techniques adapted for individual use were studied. Insufficient research has been carried out on the necessary filtration systems. […]