1986-3

The result of a part of the studies of the transport of nitrogen and phosphorus to the Svartå river within the Motala Ström river basin is given. The amount of nutrients transported to the river with the storm water from the city of Mjölby has been estimated. By maps and field investigations the size of […]

A mixed wastewater from different food-processing industries has been treated in two pilot-scale aerated submerged biological filters. Plastic media with specific surface areas of 140 m2/m3 and 230 m2/m3, respectively, were used. A maximum volumetric removal rate in excess of 15 kg COD/m3d was obtained with the 230 m2/m3filter medium. In order to perform properly […]

The occurrence of copper, zinc, lead, cadmium and chromium in water distributed by Finnish waterworks was investigated in 1983. The volume of water from the 55 waterworks investigated covers 67 % of the total volume of public water supplied in Finland. The total number of water samples was 863. The possible connection between the occurrence […]

The concentrations of oxygen, nitrate, phosphate, particulate organic matter and planktonic algae around a cage fish farm during an annual cycle showed values similar to the concentrations in the water of the surrounding sea area. There was no increase of nutrients and no denser growth of algae in the cage fish farm. The concentration of […]

Based on experimental studies in a pH-stat the dissolution kinetics for K-slag, a tricalcium silicate, was determined. The expression is: [CHEMICAL FORMULA NOT INCLUDED] where the rate constants at 20°C are given by: pKi =5.36±0.18, pKW=8.15±0.08 and pKB= 7.3 ±0.06. The dissolution of K-slag is slower than calcite dissolution but faster than dolomite dissolution at […]

A conceptual model for simultaneous computation of runoff and inorganic nitrogen leaching has been developed and tested. The model is semiempirical with coefficients that are calibrated against observed data. The model has been verified against data from two small fields of arable land in southern Sweden. The results indicate that a major part of variations […]

Muscle mercury accumulation in Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) have been studied in two small acidified coastal watersheds in S.W. Norway. Individual mercury concentration varied between 0.05 and 0.31 ppm (ìg/g) Hg, and increased significantly with age in all fish stocks, except one. Brown trout from Lake Djupvikvatn had the highest […]

Possible reasons for the development of greater numbers of bacteria in paper-mill processes from the time around 1965 and onwards are discussed. The proportion of enterobacteria was relatively constant, a few per cent of the colony forming units (CFU) with Klebsiella, Enterobacter, and Erwinia dominating among members of Enterobacteriaceae. The concern for the possible effects […]

Vid Mjölkulla reningsverk i Mjölby startades under perioden april-augusti 1985 ett försök med Alfax’ AIROXAL-process. Initiativtagare från Mjölby kommun var driftingenjör Börje Karlsson. Ett samarbete för försöket kom till stånd mellan Mjölby kommun, VIAK AB och Alfax AB. Försöket blev lyckat och som första kommun i Sverige kommer en permanent utrustning att installeras vid reningsverket […]

Försök har utförts att avvattna och fosforfälla brunnsslam från Stockholms skärgård med hjälp av dels en Moos avvattningscontainer, dels en Reductor siltrumpress. För avvattningen har olika polyelektrolyter provats, och för fosforfällningen har järnklorid, aluminiumsulfat och Ekoflock använts. Undersökningen visar att fosforhalten kan sänkas från 50 mg/l till 1 a 2 mg/1, COD från 3 000 […]