BORTPUMPNING AV SJÖARS BOTTENVATTEN FÖR ATT MINSKA INTERNBELASTNINGEN AV FOSFOR Erfarenheter från Bornsjön / Hypolimnetic withdrawal to reduce internal phosphorus loading in lakes Experiences from Lake Bornsjön
Eutrophication of lakes is a serious problem, especially in agricultural areas. It is mainly due to external and internal loads of phosphorus (P), which increase the P concentration in the lake water. Lake Bornsjön is a reserve source of water supply for Stockholm and is located 25 km southwest of the city. Maximum yearly concentration […]
PARTIAL NITRITATION PROCESS ASSESSMENT
In this study, partial nitritation has the aim to oxidise a fraction of ammonium (about 50–60 %) into nitrite without following oxidation to nitrate. Experiments performed during eight months describe partial nitritation of supernatant from dewatering of digested sludge at Himmerfjärden wastewater treatment plant in the south Stockholm region. The process was the first step […]
NÄRINGSÄMNESRETENTION I EN ANLAGD VÅTMARK – EN INTENSIVSTUDIE AV ORMASTORP S / Nutrient retention in a constructed wetland – case study South Ormastorp
South Ormastorp is a constructed wetland in the Råå river catchment area located in the northwest of Skåne. The aim of the wetland is to decrease the diffuse leaching of nutrients from Råå river to Öresund. During three weeks South Ormastorp was intensively studied. Runoff was continuously measured and water samples were collected daily (Monday–Friday), […]
Om förekomst av bekämpningsmedelsrester i grundvatten:erfarenheter från simrishamn kommun 2002–2007 / Monitoring of pesticides in rawwater wells in Simrishamn
In January 2007, all municipal water wells of Simrishamn, south Sweden, were sampled and analyzed for the presence of pesticide residuals. In total 34 wells were analyzed. The samples were analyzed at an accredited laboratory with respect to 77 different parameters of pesticides which either are used or have been used in the recharge area […]
Hydraulic capacity of 2in1 sewers
It is today possible to have an extra pipe installed in an existing sewer with traditional cured in place (CIPP) technology. Such an installation will affect the capacity of the sewer. The cross sectional area will decrease and the hydraulic radius will increase which decreases the capacity. The new liner will have a smother surface, […]
Vågdämpning i bestånd av vass (Phragmites australis) / Wave attenuation in stands of common reed (Phragmites australis)
Common reed is found in near-shore areas of many European lakes, where it frequently forms dense stands. In order to evaluate the effects of common reed stands on waves and to test a model for wave attenuation caused by vegetation, a field experiment was conducted in the common reed stands of a southern Swedish lake. […]
INHIBITION OF THE NITRIFICATION PROCESS OF ACTIVATED SLUDGE MICRO-ORGANISMS BY SCRUBBER WATER FROM AN INDUSTRIAL FLUE GAS CLEANING PROCESS
The microbial transformation of ammonia to nitrate, the nitrification, is a central process in the nitrogen biogeochemical cycle. In a modern wastewater treatment plant, the nitrification process is a key process in the removal of nitrogen and inhibitory compounds in sewage can seriously affect the nitrogen removal. A major sewage cleaning plant in the southern […]
Oxygen uptake rate measurements for application at wastewater treatment plants
Increasing discharge demands put higher pressure on process optimisation and control of the wastewater treatment plant performance. For evaluation and regulation of the process performance, oxygen uptake rate (OUR) measurement is a useful tool. In this paper one way to perform oxygen uptake rate measurements is described. Possible applications of the method for wastewater treatment […]
ENERGIEFFEKTIVISERING AV LUFTNINGSSTEGET PÅ KÄPPALAVERKET, LIDINGÖ / Energy optimization of the aeration at Käppala wastewater treatment plant, Stockholm
In conventional wastewater treatment plants the aeration of the biological treatment process is often one of the largest energy consumers. As a part of making Käppala WWTP more energy efficient three full-scale optimization experiments of the biological treatment process have been performed. In this article, the different strategies are described and evaluated and the results […]
Two years of experience with semi-technical scale membrane bioreactor (MBR)
In wastewater treatment applications the MBR technology combines biological treatment and a membrane system to provide organic and suspended solids removal. Installation of low-pressure membranes within a biological reactor system replaces sedimentation, screening and media filtration as means of separating mixed liquor suspended solids (MLSS) from treated wastewater. This study is focused on experiments with […]