VANDPLANLAEGNING OG FORUDSIGELSER Usikkerheder i data, modeller og beslutninger i miljöplanlägning / Predictions in Water Resources Planning Uncertainties in data, models and decisions
The development and application of simulation models in water and environmenral planning and management have expanded greatly over the last decades. Such models are used in, for example, water quality assessments, and it is expected thai models will be applied for analyses and decision making to a greater and greater extent in the future. However, […]
BOTTNARNA I ÅSFJORDEN, VÄNERN, KARAKTERISERADE MED BILDANALYS / Benthic habitat quality assessment of Åsfjorden, Lake Vänern, by sediment profile imaging
In September 1997, the benthic habitat in Åsfjorden in Lake Vänern was studied at 23 stations by sediment profile imaging. Grab samples for qualitative analysis of the fauna was taken at nine stations. The sediment surface was oxidized at all stations and showed indication of biological activity by rubificids and chironomids in the entire Åsfprden. […]
ANAEROBIC DIGESTION AND THERMAL HYDROLYSIS TO REDUCE PRODUCTION OF SLUDGE IN WWTPs
Mesophilic and thermophilic digestion of primary and activated sludge was investigated in lab scale reactors. Mixed primary and activated sludge was digested in one experiment and activated sludge was digesred alone in another. The same gas yield, COD and dry solids reducrion was obtained with both mesophilic and thermophilic digestion. However, more dissolved COD was […]
LÄMPLIGA EGENSKAPER HOS MODELLER I VATTENPLANERING / Appropriate Properties of Models in Water Management
Models and modeling require management of the inherent complexity. Simplicity in models and modeling is a positive characteristic. Models and modeling possess no intrinsic value. Their value may be assessed only relative to an objective or a problem to be solved.
EXPERIENCES WITH ONLINE MEASURING INSTRUMENTS FOR SBR-OPERATION IN KALMAR / Erfarenheter av online-mätinstrument för SBR-driften i Kalmar
Expansion for nitrogen reduction on Kalmar wastewater Treatment Plant (KARV) was realized with 2 sequencing batch reactors (SBR) for separate treatment of filtrate water. Online measuring instrumems were installed to make control of the SBR-process easier. The waterlevel and DO-meters are used for automatic operation control, whereas information on sludge content, pH, redox-pontential, ammonium and […]
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 […]