MODELLING NITRIFYING TRICKLING FILTERS / Modellering av nitrifierande biobäddar
Nitrifying trickling filters (NTFs) have attained renewed attention due to increasing demands on nitrogen re moval in municipal waste-water treatment. For improved control of wastewater treatment plants (WWFPs), using NTFs, models of the filters are almost indispensable. Furthermore, models may be used to improve the understanding of the process and for studying new operational strategies […]
DESIGN AND OPERATION OF A PILOT-SCALE ACTIVATED SLUDGE PLANT / Utformning och drift av en aktivslamanläggning i pilotskala
This paper describes the design and operation of a novel pilot-scale activated sludge plant located at the main municipal wastewater treatment plant in Uppsala, Sweden. The pilot plant consists oftwo separate lines for predenitrification. The main purpose of the plant has been to study new methods for efficient nutrient removal using advanced process technology, applied […]
EFFECTS OF WEIGHTING AGENTS AND SEEDED NITRIFICA- TION BACTERIA ON THE ACTIVATED SLUDGE PROCESS – EVALUATION BY USE OF SIMPLE MODELS / Effekter av tyngande material och inympade nitrifikationsbakterier på aktivslamprocessen – Utvärdering med hjälp av enkla modeller
Many possibilities are available to improve the efficiency of the activated sludge process and to decrease the necessary volume needs. Examples include the use of dosage of weighting agents and seeding of nitrification bacteria to the activated sludge process. Simple models were developed in order to predict the effects of these methods. One model was […]
PHOSPHORUS REMOVAL AND DENITRIFICATION IN DEEP-BED TWO-MEDIA FILTERS / Fosforavskiljning och denitrifikation i djupa tvamediafilter i Henriksdals reningsverk i Stockholm
Simultaneous suspended solids separation, denitrification, and phosphorus precipitation in a down-flow filter were studied as a final process step at Henriksdal treatment plant. The research was performed in a stainless steel tube with a diameter of 0.4 metre filled with sand of different grain sizes and layer heights over a layer with expanded clay. The […]
Kommentar till Artikel om Sveriges genomförande av EG:s ramdirektiv för vatten i Tidskriften vatten nr 3, 2007 »Är kraven i EG:s vattendirektiv rimliga?» (Lidén, Förlin och Persson, 2007)
Författarna drar en slutsats att kraven i EG:s ramdirektiv för vatten, som det genomförts i Sverige, inte är rimliga. Slutsatsen är baserad på en rad felaktiga antaganden. Författarna bortser mer eller mindre från den kommande samverkansprocess som föregår de viktigare besluten inom vattenförvaltningen. De bortser även från de möjligheter till undantag från kravet på god […]
Barriärtänkande vid extrema förhållanden / Multiple barriers under extreme situations
The demand for water increases with population and economic growth. Water that in many cases not is available. Reclaimed water for irrigation has been used for a long time, but in urban areas with water scarcity, advanced treated wastewater has now become an alternative for production of potable water. Extreme situations demand ingenious solutions, solutions […]
ØSTENSJØVANNET – A SHALLOW HYPERTROPHIC LAKE IN NORWAY WITH SIGNIFICANT INTERNAL PHOSPHORUS LOADING DURING SUMMER
Lake Østensjøvannet is a shallow hypertrophic lake situated about 30 km south of Oslo. The water quality in the lake during the last hundred years has deteriorated greatly. The main reason for this is supply of wastewater and drainage from agricultural activities. Investigations in the summers of 1977 and 1978 indicated very high internal phosphorus […]
FRAMTIDA VATTENFÖRSÖRJNING FÖR VÄXJÖ KOMMUN – BEDÖMNING AV OLIKA ALTERNATIV / Future Water Supply of Växjö Municipality – Evaluation of different alternatives
Water supply in Växjö municipality has since 1887 been based on surface water from Helga lake. A water treatment plant was built in 1957 and was extensively reconstructed in 1969 but there are still problems to accomplish with drinking water quality, mainly related to temperature, smell and taste, managanese and aluminum rest. Present water consumption […]
Implementing Resuspension Potential Method to optimise Yarra Valley Water’s mains cleaning program
Routine cleaning of water mains is commonly employed by water utilities around the world as a proactive means of managing common water quality issues. When employed correctly, mains cleaning can be effective in removing loosely deposited sediments that can cause water discolouration. Despite its long history in the water industry, water supply practitioners continue to […]