FÖRSLAG TILL EKOTOXIKOLOGISK RISKBEDÖMNING AV SEDIMENT – INTEGRERAD KEMISK OCH BIOLOGISK KARAKTERISERING / Proposal for an ecotoxicological risk assessment of sediments – An integrated chemical and biological characterisation
A strategy for the sampling, analysis and biological assessment of sediments contaminated from a variety of sources in urban areas, such as industry and surface run off is suggested for Swedish conditions. The strategy is suitable for an initial assessment of chemical content, bio-availability, genotoxicity and the persistence of known persistent pollutants. The strategy includes […]
CRITICAL EVALUATION OF PESTICIDES IN THE AQUATIC ENVIRONMENT AND THEIR REMOVAL FROM DRINKING WATER
The presence of pesticides in the aquatic environment represents a potential threat to water quality and human health. Relatively soluble herbicides, such as the chlorphenoxy acids and triazines, applied in agriculture can reach drinking water sources. These herbicides show marked seasonal variations in concentration and have a longer residence time in groundwater and surface water […]
VÄXELVERKAN MELLAN VEGETATION OCH VATTNETS KRETSLOPP / Vegetation and water cycle interaction
The paper suggests a reciprocity between the landscape and the water cycle. Different processor properties of the water cycle dominate in different landscapes, mainly dependent on the vegetation cover and degree of ecological development. Satellite images and geographic information systems are used for recognising pattern similarities between the water cycle and the landscape. A new […]
KRAFTIGA BLOMNINGAR AV CYANOBAKTERIER OCH SAMBAND MED NÄRINGSÄMNEN I NÅGRA AV VÄNERNS GRUNDA VIKAR / Heavy blooms of cyanobacteria in Lake Vänern
Lake Vänern is an oligotrophic lake today, but in the northeast part of the lake there are three shallow bays (Ölmeviken, Varnumsviken and Kolstrandsviken) where some heavy blooms with cyanobacteria, occurred during the last ten years. In this article, the blooms and relations to the water quality and the phosphorous loads are reported and discussed. […]
AERATION BY DESTRATIFICATION: A TECHNIQUE FOR RESTORING THE WATER QUALITY OF LAKES AND RESERVOIRS
Lake and reservoir eutrophication is a complex process involving a variety of factors which are difficult to act upon simultaneously. The process is triggered off and perpetuated by nutriment inputs from the drainage basin. These may come into play at a later stage however, when the water body stratifies thermally in the summer, cau-sing phosphorus […]
n-OCTANOL/WATER PARTITION OF AQUATIC HUMUS USING SEGMENTED FLOW EXTRACTION / Mätningar av fördelningen av akvatisk humus mellan vatten och n-oktanol i vätske/vätske segmenterat flöde
Segmented flow extraction has been applied to studies of the n-octanol/water partition of aquatic humus. This material is a heterogeneous mixture of compounds many of which have surfactant properties complicating the studies. The segmented flow extraction method is proved to be a simple and useful tool for screening the lipophilicity of humus thereby aiding in […]
FLOCKBILDNING I AKTIVSLAM – VIKTIGA FAKTORER OCH FRÅGOR / Flocculation in activated sludge – important factors and questions
Activated sludge is a complex ecosystem consisting of bacteria, protozoa, yeast and virus. Because bacteria are such a large and important component of activated sludge floes, bacterial adhesion is a crucial mechanism of the flocculation. We have studied how electrostatical interactions influence floe stability and sedimentation in water with different ionic composition. Changes in floe […]
THE USE OF WOODEN PIPES IN RURAL WATER SUPPLY IN FINLAND
The paper describes the use of wooden pipes, particularly drilled pine logs, as rural water conduits in Finland. The first documented case of such a system serving a single house is from Ilmajoki, Ostrobothnia from 1865. Later on, the system was expanded and the first joint system was completed in 1872. The latter scheme was […]
ORGANIC MATTER, NITROGEN, AND PHOSPHORUS CONTENT IN SLUDGE DEWATERED BY NATURAL METHODS / Innehåll av organiskt material, kväve och fosfor i slam avvattnat med naturnära metoder
The objectives of this study were to investigate the possible effects of freeze/thaw-drying and drying as sludge dewatering methods on the organic matter, nitrogen, and phosphorus content in the sludge. The research work was carried out on three different levels. The effect of natural sludge dewatering on the overall status of the sludge was mainly […]
BIOLOGICAL REDUCTION OF HEXAVALENT CHROMIUM IN A LEACHATE FROM VARGÖN ALLOYS AB
Anaerobic biological treatment has proven to be a successful method for reducing Cr(VI) in a leachate from Vargön Alloys AB. Influent chromium concentrations ranged from 10-120 mg/L and satisfactory reduction was achieved in both laboratory and pilot plant studies, as long as sufficient amounts of electron donor were added. Glucose, acetic acid and sulfite evaporator […]