Alla artiklar

The effect of food to microorganism ratio (F:M) on nitrogen removal in intermittent cycle extended aeration activated sludge (ICEAS) system, has been studied using a large pilot scale treatment system. A basic operation schedule for BOD removal was used in the study. The objective of the study was also to develop data that would provide […]

Dosing is a common unit operation in water and sewage treatment technology. In that connection it is important to choose reliable and accurate equipment. The article describes different automatical dosing systems, different dosing pumps and claims given when selecting dosing systems. It is also important to design the installation in the right way. Examples for […]

Long-term ice-cover occurring on high-mountain and subarctic lakes as well as on brackish-water seas such as the Gulf of Bothnia promotes certain algae species, well adapted to low-light and low-temperature and/ or heterotrophic nutrition. Such algal species often belong to the dinoflagellates. In the northern Bothnian Sea, as in Lake Torneträsk, dinoflagellates are predominant under […]

The aim of the present study was to determine the pollution load originating from storm water on Lake Växjösjön. Each year about 1,050,000 m3 of storm water are discharged into the lake. Storm water represents a substantial pollution source for the lake and therefore also a main reason for the hypertrophic conditions in the lake. […]

The aim of this paper has been to discuss some results and experiences that may be drawn from the project »Environment/Cellulose l», sponsored by the National Swedish Environmental Protection Board. The emissions from pulp bleacheries consist of many complex substances, some of which are identified (like dioxins and chlorophenols), most of which are unknown in […]

The concentrations of cadmium and lead in water from 280 private wells were determined. The aim of the study was to elucidate if the presence of these metals is a health problem when the water is used as drinking water. The water in many Swedish wells is very acid and is also influenced by the […]

The mathematic models used for trickling filter design today do not give a correct picture of the influence of depth on the process efficiency. The effect of an increased filter depth is overestimated, resulting in an uneconomical design. The design models used are normally based on a first order reaction equation and the most common […]

The water treatment works named Borg delivers drinking water to about 100,000 inhabitants in Norrköping. Raw water is taken from the river Motala ström. Because of the raw water quality there are sometimes problems with bad taste and odour in the purified water. By pollution from a paper pulp factory with chlorine bleachery, situated upstreams […]

In areas with intensive agriculture land use conflicts between the agriculture land use interests and the drinking water supply protection interests are frequent. Precise methods for delimitation of Safety Control Areas are urgent. Two delimitation methods are demonstrated. The first one, delimitation by subwatersheds, is based on identifications of local hydrological interrelationships and their significance […]

In this paper the interaction between legislation and municipal administration is focused on the relationship between land use and ground water contamination. In two cases – Vadstena and Kinda – the weak protection of the vulnerable ground water from different land use activities is illustrated. Today the administration is organized for and aimed at handling […]