1993-3

The phytoflagellate Prymnesium parvum Carter, and probably Prymnesium patellifera Green & Hibberd, belong to the toxinproducing algae in the Scandinavian coastal waters. Only particular physiological strains of the species are toxigenic. The toxic properties of P. parvum are attributed to a group of chemical compounds having similar composition, but different toxic effects. The toxic principle […]

Many rivers and estuaries in Western Finland are subjected to highly acidic runoff from acid sulphate (AS) soils in their catchments. Acidic inflows, clearly exceeding the buffering capacity of the recipients, are common during most spring and autumn floods. AS soil acidity causes serious damage to the fisheries m common in the affected area. The […]

Water is scarce in Cape Verde. In Mindelo almost all fresh water is produced by desalination of sea water because of lack of fresh water. In this perspective reuse of waste water for agricultural purposes is a very interesting alternative. Mindelo is also the only city in Cape Verde with an existing infrastructure regarding the […]

Characterization is a study of the effect of waste water or a chemical on the environment. The study is carried out by biological and chemical analytical methods. Characterization of waste water plays an important role in protecting the environment and working towards a society of recycling. In this paper different characterization models for waste water […]

This paper describes a new technique to operate SBR package plants. The whole process – aeration, integral liquid flow, excess sludge withdrawal and addition of precipitation chemicals – is powered by a single side channel blower. The conclusion is that the gain of this technique are package plants extremely low in service and maintenance.

The nitrification process at Öresundsverket in Helsingborg was, during a test period of twelve weeks, effected by inhibiting substances. The inhibition was found both in laboratory tests and in full scale at the treatment plant. The laboratory tests performed are based on week samples. Despite dilution of a potential inhibitor in a week sample, two […]

Nitrification of reject water with SBR technics has been studied at Bromma sewage treatment plant in Stockholm. At the beginning of 1993 an investigation of the nitrification by use of multivariate method was carried out. Experiments showed that the nitrification rate is very strong depending on the oxygen content in water. Moreover the experiment proved […]

Focus is kept on the importance of water in sustaining life. A new concept – the aquatorium – is introduced describing waterly related processes. Out of many only some models are fit to describe energetically driven processes. Attention is made to the concept of free energy as potential work. Accurate models of hydrobiological processes and […]

Between 80 and 90 per cent of the deposition of acidifying air pollutants on Sweden originates in other countries. Most of it comes from western Europe, with Germany and Great Britain being the two biggest contributors. In the 1980s, European emissions of sulphur dioxide decreased by 25-30 per cent, while those of nitrogen oxides increased […]

The Warsaw WWTP “Czajka” was designed for the flow of 400000 m3/d. During wastewater treatment 4 800 m3 /d sludge settle down in the primary settling tanks. It’s a mixture of primary and excess activated sludge. The settling tanks are desludged three times a day and the sludge flows by gravity to 4 thickener and […]