STORM OVERFLOWS IN NORWAY- POLICIES AND PRESENT SITUATION
Storm overflows contribute considerably to pollution. However, the pollution authorities and municipalities often fail to take appropriate measures to correct the situation. Investigations in Norway have shown that the storm overflow constructions and maintenance usually are not satisfactory. On the other hand, research projects have shown that storm overflow types, like the swirl concentrator, perform […]
APPLICATION OF ION EXCHANGE AS BIOFILTER FOR COMPLETE RECIRCULATlON IN AQUACULTURE
A recently developed system for recirculation of aquaculture waste water was examinined. It is based upon the use of settling, a mixture of 3 ion exchangers, and sand filtration. The results were satisfactory, giving an acceptable water quality over a period of 7 months with complete recirculation. The ion exchange unit is also operating as […]
MUTAGENIC ACTIVITY IN DRINKING WATER AND HUMIC WATER AFTER CHLORINE TREATMENT
Mutagenic activity in Salmonella typhimurium strains TA100 and TA98 was determined for chlorinated drinking water, purified from raw water with a high content of humic material, and for a natural humic water treated with chlorine. A remarkably high activity was found for XAD-4/8 concentrates of acid water samples compared to neutral samples in tests performed […]
FULLSKALEFÖRSÖK MED NITRIFIERING AV REJEKTVATTEN FRÅN CENTRIFUGERING AV RÖTSLAM VID BROMMA AVLOPPSVERK / Full-Scale Experiments of Nitrification of Sidestreams from Centrifugation of Digested Sludge at Bromma Municipal Wastewater Treatment Plant
Bromma municipal wastewater treatment plant is the second largest plant in Stockholm with a design flow of 160,000 m3/day. Decisions were made in 1982 to study nitrification of side- streams from the dewatering of digested sludge in full-scale at Bromma in order to improve the overall nitrification capacity of the plant. The investigation is jointly […]
THE CONTINUOUS ON-LINE MONITORING OF ENVIRONMENTAL POLLUTANTS IN STORMWATER
A monitoring system is described which provides continuous measurements of selected pollutants in stormwater. The system, which has been installed at both the outfall to a storm-water pipe system and in a gullypot, is sensitive to changes in pH, conductivity, dissolved oxygen concentration, temperature and redox potential. At the stormwater outfall monitoring station rapid changes […]
FRAMTAGNING AV ETT DATORBASERAT REGLER- OCH INFORMATIONSSYSTEM FÖR CENTRIFUGPROCESSEN VID SICKLA SLAMBEHANDLINGSANLÄGGNING I STOCKHOLM / A Computer Based System for the Centrifuge Process in Sewage Treatment
It has been more and more common to use centrifuges for the removal of sludge during sewage processing. The centrifuge process is relatively complex and requires valuable polymers to be effective. In addition reject water is re-introduced for re-purification which usually entails an inordinate extra load on the sewage plant, particularly during periods of high […]
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 […]