BESTÄMNING AV NITROGEN I AVLOPPSVATTEN MODIFIERAD KJELDAHLMETOD / Determination of nitrogen in effluents. Modified Kjeldahl method
A modification of the Kjeldahl method has been tested in a collaborative study involving 16 laboratories. The method measures the sum of organic and inorganic nitrogen in industrial and municipal effluents. Nitrate and nitrite are reduced with Devarda’s alloy and the organic material is destroyed with sulphuric acid in the presence of copper. The ammonium […]
AN AUTOMATIC METHOD FOR FRACTIONATION AND DETERMINATION OF ALUMINUM SPECIES IN FRESH-WATERS
An automatic method for fractionation and determination of aluminum species in natural waters is described. The method is an automatic modification of the catechol violet method of Dougan and Wilson (1974). The fractionation step is an automatic modification of the ion-exchange procedure suggested by Driscoll (1980). The method yields three aluminum fractions: total monomeric aluminum […]
DETERMINATION OF SULFATE IN WATER – EVALUATION AND INTERCALIBRATION OF METHODS
In connection with the inter-Nordic standardization (INSTA) of methods in water chemistry, some methods for the determination of sulfate have been evaluated. Two manual spectro-photometric methods were tested, one based on the reagent thorin and the other on methyl thymol blue (MTB), but neither of them were acceptable; the thorin method had a too narrow […]
ÅRSTIDSVARIATIONER I VÄXTNÄRINGSTRANSPORTEN TILL LAHOLMSBUKTEN / Temporal Variations in Nutrient Transport to the Laholm Bay
The Laholm Bay on the Swedish west coast is a part of the estuarine system connecting the Baltic and the Atlantic. Its hydrography is characterized by a strong vertical stratification. Intensive plankton blooms and mass development of Cladophora have occurred during the last ten years. Low oxygen concentrations, and even hydrogen sulphide, have been observed […]
BOTTENLINSER OCH NÄRSALTSDYNAMIK I LAHOLMSBUKTEN / Bottom Lenses and Nutrient Dynamics in the Laholm Bay
The linkage between (1) bottom dynamics, i.e. where areas of erosion (E), transportation (T) and accumulation (A) prevail, (2) lenses, i.e. fine highly moveable material-living and dead, inorganic and organic, recent and resuspended-that can be found on shores and on generally harder deposits predominating on E- and T-bottoms, and (3) the flux of nitrogen, which […]
HUR TILLFRISKNADE SJÖARNA? / Research on Recovery of Polluted Lakes
In order to evaluate the effects of advanced wastewater treatment plants for phosphorus removal, the National Swedish Environment Protection Board during 1971 started a program for analysing the conditions in a number of recipient lakes. Some lakes from which sewage effluent was completely diverted were included. Of 23 lakes possible to evaluate, 15 responded positively […]
The ReAl Process – A COMBINED MEMBRANE AND PRECIPITATION PROCESS FOR RECOVERY OF ALUMINIUM FROM WATERWORK SLUDGE
The aim with this study has been to find a process which can recover aluminium from waterworks sludge. The separation processes used include acidification, ultrafiltration, nanofiltration and precipitation. The result of this study, which has been carried out over a period of three years, strongly indicates that it is technically possible to use acidification combined […]
HVA ER BÆREKRAFT OG HVORDAN KAN MAN SAMMENLIGNE BÆREKRAFTEN I ULIKE SYSTEMER? / What is sustainability and how can we compare different systems?
The aims of this article are to increase the awareness of sustainability as a tool to obtain more sustainable infrastructure and to show how sustainability may be calculated. The sustainability of an infrastructure may be assessed by using a set of indicators and a subsequent weighing process implemented on these indicators. Politicians should take part […]
RENINGSEFFEKT MOT KOSTNADSEFFEKTIVITET I ANLAGDA VÅTMARKER / Retention capacity versus cost efficiency in constructed wetlands
A large number of wetlands have been created in the northwest part of Scania (south of Sweden) since 1991. Their types of construction vary, which affect their ability to remove nutrients from eutrophic watercourses. In this report, we have evaluated how different construction techniques affect nitrogen retention capacities andcompared cost-efficiencies between different wetlands. The wetlands […]