1990-4

This project is a summary of the work carried out within the project Liming – Mercury – Cesium in the Örebro county. The basic question is: How is it possible to reduce the mercury and cesium content in fish and the threat of “blacklisting” presently acute for about ten thousand Swedish lakes? What measures could […]

The aim of this paper is to present and discuss some results from the project “The Coast As a Natural Resource”. The overall aim has been to attempt to develop new scientific criteria, methods and models for the planning of coastal waters. The sensitivity of different coastal areas to nutrient loading (nitrogen and phosphorus) from […]

High concentrations of iron in drinking water, redwater, is a problem in some parts of Gothenburg. Iron concentration is determined in redwater areas by analysis of samples taken out of hydrants. Unfortunately it is very difficult to compare results from different samples and to find tendencies as different methods are used. During the investigation many […]

In many agricultural areas the small streams have been reduced to drainage ditches. This not only has destroyed important natural habitat but has reduced the self cleaning and nutrient reduction ability of agricultural streams. There is now much discussion about how this trend can be reversed in a practical and cost effective way without disrupting […]

Okome samhälle har ca 180 personer vilka är anslutna till reningsanläggningen som utgöres av 2 st biologiska dammar. Dammarna anlades i mitten på sextiotalet och drevs konventionellt fram till 1986. Reningsanläggningen kompletterades sedan med kalkfällning och kalksilon med doseringsutrustning placerades mellan första och andra dammen. Reningsresultaten för åren 1987-1990 visar att anläggningen har fungerat bra. […]

The paper deals with a research programme that the Norwegian environmental control authorities have established in order to be able to recommend how the municipal discharges of nutrients to the North Sea may be reduced by 50 % within 1995. The strategy is to ensure phosphorus removal by chemical treatment for all plants > 5,000 […]

Two concepts for nitrogen removal using submerged biological filters are discussed, namely pre-denitrification followed by combined precipitation and pre-precipitation followed by post-denitrification. The preliminary design basis is presented, together with a design example and cost figures. Pre-denitrification is the preferred method for moderate nitrogen removal efficiencies (70 %) or if the wastewater is very dilute […]