MIKROBIOLOGISK OCH KEMISK OXIDATION AV MANGAN I RÅVATTEN / Microbial and chemical oxidation of manganese in raw water
The oxidation kinetics of manganese in a sandfilled column has been studied. The oxidation pathways can be both chemical and microbiological. The rate limiting step during chemical oxidation of manganese is the autocatalysis of manganese (II). The time to half the manganese(II) concentration from 1,1 to 0,55 mg/l at pH 8,5 was calculated to 30 […]
VAD ÄR FISKEN VÄRD? FRITIDSFISKET I EMÅNS AVRINNINGSOMRÅDE / What is the value of fish? Recreational fishing in the River Emå Catchment
The Emå River is one of the largest catchments in South Sweden. Efforts are made to develop sustainable tourism in the area. Recreational fishing is an important activity, that will have a potential to grow. The Emå River has a special and famous attraction, namely two species of salmon (salmo trutta and salmo salar) of […]
KANALERNA I GÖTEBORG – VATTEN OCH FISKAR – EN MILJÖBIOLOGISK STUDIE / The Canals in Göteborg – Water and Fish – an Environmental Biology Study
Investigations and studies of documentation show that the situation for the fish and the water quality in the Göteborg canals are better than 100 years ago thanks to the early construction and successive improvements of the sewer system. The river Göta älv has nowadays the greatest influence of the water quality in the canals due […]
GRÖNA TAKS PÅVERKAN PÅ DAGVATTENKVALITÉN / Green roofs influence on runoff water quality
The influence of extensive sedum-moss green roofs on runoff water pollution loads was studied for four full scale installations located in southern Sweden. The aim of the study was to ascertain whether the green roof behaves as a sink or a source of pollutants on annual basis and if runoff quality depends on a roof’s […]
MICROSCREENING FOR STORMWATER TREATMENT
A competitive system for stormwater treatment should provide efficient particle removal, small footprint, rapid start-up, robustness, cost effectiveness and flexibility. Chemical pre-treatment followed by microscreening could fulfil these requirements. Thus the potential in such a system was investigated within the framework of a project involving Kemira Kemi AB, Hydrotech AB and the Department of Water […]
USE OF MAGNETIC ION EXCHANGE TO IMPROVE DOC-REMOVAL
Problems associated with the amount of dissolved organic carbon (DOC) in drinking water treatment are very common. They range from the very obvious ones like treated water taste and odour and appearance, to the less understood disinfection by-product formation, bacterial regrowth in distribution network, exhaustion of activatedcarbon, membrane fouling and increased coagulation chemical demand. Ion […]
A COMPARATIVE STUDY OF SIX HYDROPONIC WASTEWATER TREATMENT PLANTS
During the last two decades, wastewater treatment in systems combining conventional biological processes and hydroponics has been tried at several locations. In this article, six different systems are described and their treatment results compared. Five systems were found in literature, and the sixth system was constructed and operated by the microbiology group at KTH. These […]
DESIGN OF WASTEWATER TREATMENT PLANTS USING SUBMERGED BIOLOGICAL FILTERS FOR NITROGEN REMOVAL
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 […]
NORWEGIAN STRATEGIES IN THE TREATMENT OF MUNICIPAL WASTEWATER TOWARDS THE REDUCTION OF NUTRIENT DISCHARGES TO THE NORTH SEA
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 […]
FALKENBERGS KOMMUN – OKOME AVLOPPSRENINGSVERK Kvävereduktion i biologiska dammar
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. […]