LÄCKSÖKNING PÅ SJÖLEDNING I BORÅS / Leakage detection on a pressure main situated in a lake in Borås
Pressure recordings during transient conditions can be utilized for leak detection purposes on single pipes. This method has been described in a research project report CVA-Forsk, 1997) by the authors. In this case study a pressure main, situated in a lake and subjected to a leak, was examined by using pressure recordings. Two possible leak […]
VAD BESTÄMMER KOSTNADEN FÖR ATT ANLÄGGA VÅTMARKER SOM KVÄVEFÄLLOR? / What are the determinants of costs of creating wetlands as nitrogen sinks?
Wetland creation costs and their determinants are studied by an analysis of detailed dara on wedand creation programmes for causing nitrogen reducdon in two drainage basins in the agricultural district of SW Scania, southernmost Sweden. Estimated cost equations illustrate the importance of excavarion efforts for obtaining good predicrions of creation costs. An analysis of the […]
SUSTAINABLE URBAN WATER MANAGEMENT.
The Swedish urban water systems have been in use and under continuous development for more than a century. The urban water systems of today fulfil to a high degree basic requiremenrs concerning safety, hygiene and protection of the environmeni. For the past years, however, the systems have been criticised from the viewpoint of sustainability. The […]
WATER MANAGEMENT RESEARCH TOWARDS CATCHMENT- BASED STRATEGIES FOR SUSTAINABLE RESOURCE USE / strategisk vattenforskning för uthållig resursanvändning i avrinningsområden
The paper presents the Swedish Water Management Research Program towards catchment-based strategies for sustainable resource use (VASTRA). The major goal ofVASTRA research is to develop catchment-based water management strategies which are sustainable from ecological, economical and social perspectives. As a. point of departure, VASTRA views catchments from three pardy overlapping resource perspectives. The first one […]
RÖRLIGA BÄRARMATERIAL FÖR BIOLOGISK AVLOPPSVATTENRENING – EN SAMMANSTÄLLNING AV DRIFTSERFARENHETER / Moving bed carriers for biological wastewater treatment – A summary of experiences
A large number of biological processes have been developed to meet different needs since the early forms of the trickling filter and the activated sludge process were introduced. One of the goals developing new processes often was to increase the total amount ofbiomass in the process. In several of these new processes, the surfaces of […]
NITRIFIKATION I BIOBÄDD OCH DENITRIFIKATION I EN HÖGBELASTAD AKTIVSLAMANLÄGGNING – DRIFTERFARENHETER FRÅN RYAVERKET / Post nitrification in a trickling filter and predenitrifaction in a non-nitrifying activated sludge system – operational experience from the Rya WWTP
The Rya Wastewater Treatment Plant, serving the Göteborg Region on the West Coast ofSweden has been ex- ended for nitrogen removal. The process includes post nitrification in trickling filters and predenitrification in non-nitrifying activated sludge system. In this paper some experience from the first year of full-scaleoperation will be related. The staied effluent standard of […]
DECLINING WATER CONSUMPTION IN COMMUNITIES: SIGN OF EFFICIENCY AND A FUTURE CHALLENGE
The paper describes the trends of water consumption, particularly per capita in Finland from 1970 to 1996 and includes comparisons from other countries. The per capita consumption started to decline due to two major impetus; the energy crisis of 1973 and the Wasrewater Surcharge Act of 1974. The latter more than doubled the average price […]
COMPARISONS OF HYDROGRAPHS FROM A KINEMATIC WAVE MODEL AND TWO DYNAMIC MODELS / Sammenligning av hydrogrammer fra en kinematisk bolgemodell og to dynamiske modeller
This paper describes differences between the urban drainage models MOUSE, EPA-SWMM and NIVANETT, relating to the routing of flows through pipes. NIVANETTs kinematic wave procedure simulates rather similar hydrographs to those of MOUSE, when the conduit lengths are shorter than ca. 500 m and the slope is steeper than ca. 1/1000. Keeping in mind that […]
CHEMICAL OXYGEN DEMAND (DICHROMATE VALUE) AND THE SWEDISH BAN ON MERCURY, OPPORTUNITIES AND PITFALLS
The Chemical Oxygen Demand (COD) test is a key parameter for process control and the routine monitoring of effluent quality in wastewater. However, the present procedure for determination has ro be replaced becausethe scale of COD test chemicals containing Hg will probably not be permitted after the year 2000 in Sweden. Mercury-free procedures are reviewed […]
DISTRIBUTION OF MICROORGANISMS IN THE COURSE OF ARTIFICIAL RECHARGE OF GROUNDWATER AT BALTEZERS WATERWORKS, RIGA / Fördelning av mikrorganismer vid Baltezers anläggning för konstgjord infiltration i Riga
Artifcial recharge of groundwater is being used for drinking warer production in Latvia. The ultimate removal of organic matter from the surface water during artificial recharge of groundwater is accomplished by microrganisms living in the subsurface. In order to predict changes of water quality, more information about the disribution of microorganisms between infiltration ponds and […]