1997-2

Ships, especially huge car-ferries, cause shore erosion and influence the littoral benthic communities along the archipelago routes between Sweden and Finland. Less is known about effects on pelagic communities (phytoplankton). Some effects of ships waves and currents were studied in the Mariehamn ferry harbour area, southern Åland (N. Baltic Sea) in the summer of 1996. […]

Water purification with membrane technology was investigated as one of the alternatives for the rurure drinking water production (6,000 m^/d) in Nynäshamn community. The selected raw water source was surface water from Lake Muskan rather than brackish water from the Baltic Sea. The lake water, without need for desalination, has a high colour number (up […]

In recent years, reconstructing municipal water distribution systems and optimizing their operate conditions have become important tasks in Latvia. Such work requires knowledge of the water balance within water distribution systems to make further decisions. Recorded statistics indicate high domestic water consumption per capita while consumers complain of frequent water shortages at their taps. Different […]

The area served by Anglian Water is one of intensive arable agriculture, leading to many of it’s sources of drinking water exceeding EU Maximum Acceptable Concentrations of nitrate and pesticides before treatment. Concentrations and trends in surface and groundwaters are discussed in the light of recent developments in UK agriculture and legislation. Methods are available […]

Mass-balance studies of nitrogen, phosphorus, and suspended matter have been carried out in a created pond. The pond is situated in the drainage basin of a farmland stream in Scania, southern Sweden. The investigation started shortly after the creation of the pond and has continued for three years. The aim of the study was to […]

The cost for reduction of nitrogen in created ponds does not exceed 45 SEK per kilogram nitrogen. This result is based upon the costs for the creation of ponds with a total area of 27 hectares in southwest Scania 1992-1996, and results from nitrogen budget studies of one pond during three years. Three municipal wastewater […]

Hydraulic transients occur at rapid flow changes in pressurized water conveying pipelines. Normally such transients (waterhammer) are considered to be a problem as they might damage the pipeline due to strong pressure peaks, subatmospheric pressures or fatigue. However, normally occurring hydraulic transients have also a potential to be utilized in an advantageous manner. ‘The idea […]

There are wastewater treatment plants in Uppsala municipality with both high and low copper concentrations in the sludge, this is somewhat surprising as the raw water (groundwater) often is pumped up from the same esker (gravel ridge or glacial origin), the chemical composition or the water is expected to generate strong copper corrosion, as the […]

The Swedish company, VYRMETODER AB has developed a means of treating water in an artificial aquifer according to the VYREDOX method. The method is based on degassing and aeration of raw water which is then infiltrated into the artificial aquifer. The article informs about three VYRAKVI plants installed in the mountainous region in the north […]

The hardness of water, or rather the concentration of calcium and the alkalinity, has throughout the years been described with great diversity and imagination. The aim has always been to simplify the actual, nuanced and complex chemistry in question. The many assumptions and terms for these simplifications have in course of time become vague or […]