ALTERNATIVA METODER FÖR ATT LÖSA PROBLEMET MED ROTINTRÄNGNING I AVLOPPSLEDNINGARNA / Alternative Methods to Avoid Operational and Maintenance Problems with Tree Roots in Storm Water and Sewer Pipes
Tree roots entering sewer pipes is an expensive problem which can lead to serious conflicts of interest beween arborist and sewer companies. A substantial amount of money is spent each year on different meaures to remove the roots after they have grown into pipes. The most frequently used methods to prevent root penetration are designed […]
FÖRORENINGSHOTEN MOT BOTTNISKAVIKEN Pollution Threats to the Gulf of Bothnia
The largest point emissions of heavy metals and persistent organic substances in the land area surrounding the Gulf of Bothnia have now been virtually eliminated. Despite this, the environment in this region is not approaching a preindustrial state.Like other regions, the Gulf of Bothnia region is affected by long-range atmospheric transport of persistent organic substances. […]
OMSÄTTNING AV NÄRSALTER I BOTTNISKA VIKEN 1991 / Nutrient Dynamics in the Gulf of Bothnia, 1991
Based on the intensive hydrochemical measurements during the Gulf of Bochnia Year 1991, we present descriptions of the regional variations of freshwater and nutrient inputs and hydrographic and nutrient conditions in the basins for this particular year. These data are then used to construct budgets of silicate, inorganic and organic nitrogen and phosphorus for the […]
BOTTNISKAVIKENS EKOLOGI: NÄRINGSVÄVSSTRUKTUR, MATERIALFLÖDEN OCH TRENDER / Food Web Structure, Carbon Flow and Trends in the Gulf of Bothnia, Baltic Sea
The reason(s) to the marked ecological differences berween the Bothnian Bay and Bothnian Sea, and the potential coupling to their different biogeochemistry, is unclear. Lack of simultaneous estimates of ecological parameters with sufficient spatiotemporal sampling frequency in the off-shore environment hampers the understanding of the marine food web in the Gulf of Bothnia. To improve […]
FYSISK MILJÖ I BOTTNISKA VIKEN / The Physical Environment of the Gulf of Bothnia
The Gulf of Bothnia makes about 29 % of the whole water volume of the Baltic Sea. The water exchange between the Baltic Proper and the Gulf is good, which results in a water renewal time of only about 4 to 5 years. This is one of the reasons why there is no lack of […]
ORGANISATIONER FÖR SAMORDNAD MARK- OCH VATTENFÖRVALTNING / River Basin Entities for Integrated Water Management in Sweden
The paper summarizes a research investigarion of 51 river basin entities in Sweden. These entities cover about 2/3 of the total land area. A questionnaire was sent to the entities. The member circle is multifold, but the most common combination is composed of representatives from local municipalities, industries and a few authorities. The questionnaire reveals […]
IMPROVED REMOVAL OF BACTERIA BY SUBDIVIDING A STABILIZATION POND AT THE WASTE WATER TREATMENT PLANT IN MINDELO, CAPE VERDE
The waste water treatment plant in Mindelo is oversized, with high evaporation and increasing salinity in the effluent water as a result. By subdividing the ponds with a plastic barrier, a much smaller volume is needed to achieve acceptable bacterial concentrations in the effluent water. The technique of subdividing ponds with a plastic barrier is […]
VÅTMARK OXELÖSUND – FULLSKALEFÖRSÖK MED KVÄVERENING I ANLAGDAVÅTMARKER / Wetland Oxelösund – A Full Scale Experiment with Nitrogen Removal in Created Wetlands
A wetland area, including 22 ha of shallow ponds, channels and Inundated fenlands, has been created during 1993 adjacent to the town of Oxelösund (12500 inhabitants) on the Baltic coast of Sweden. The primary goal with the wetland is an annual removal of 22 tonnes of nitrogen from pretreated wastewater from the towns treatment plant. […]
MASSBALANSER OCH RENINGSEFFEKTER AVSEENDE NÅGRA METALLER VID LUNDS RENINGSVERK / Mass Balances and Removal Efficiencies of Some Heavy Metals at the Sewage Treatment Plant in Lund
Samples of incoming raw sewage vater have been collected on a five day basis every week during six months, and analyzed for seven heavy metals. A few determinations of other elements have also been made. These data have been combined with the results of the compulsory analytical control of effluent water and sludge to calculate […]
NY METOD FÖR SPOLNING AV SNABBSANDFILTER MED VATTENSTRÄLE / New Method for the Flushing of Rapid SandWers using High-speed Water Jets
There is an increasing need for rapid sandfilters in sewage treatment plants due to more stringent requirements on the quality of the treated water. Besides sandfilters could possibly be used for other treatment processes such as chemical precipitation or denitrification. These factors imply a heavy load of suspended particles on the sandfilters making the flushing […]