STOCKHOLMS VATTENFÖRSÖRJNING OCH AVLOPP KORT HISTORIK / Stockholm’s Water Supply and Sewerage. A Brief History
The location of the settlement that became the nucleus of today’s Stockholm was a success from the point of view of water supply. A huge boulder-ridge, which provided wells with abundant supplies of water, passed through Stadsholmen – the area now referred to as Gamla Stan. The esker enters the current city area at Norrtull […]
FÖRNYELSEARBETET VID STOCKHOLMS VA-VERK UNDER DE SENASTE FEM ÅREN / Reorganization and Redevelopment Work at Stockholm Water and Wastewater Works over the Past Five Years
It is the task of Stockholm Water and Wastewater Works to operate water supply and sewage treatment plants and to be responsible for the pipeline systems for water and wastewater in Stockholm. The city’s first waterworks was commissioned in 1861, and it is only natural to assume that many aspects of the technical systems have […]
LUFTNING-OMRÖRNING I LÅGBELASTADE BIOLOGISKA RENINGSSYSTEM / Aeration-Mixing in Aeration-basins with Low Organic Load
The possibility to reduce power consumption in aerated lagoons by means of a combination of mixers and aerators is discussed. Two theoretical examples based on recent studies in the US and experiences from aerated lagoons in Sweden and Tunisia are calculated to show the potential energy saving by using mixers and aerators in combination. The […]
VATTENVÅRD I LAGANS FLODOMRÅDE UNDER 30 ÅR – ETT EXEMPEL PÅ VATTENPLANERING / Water Protection in Lagan River Basin during 30 Years – An Example of Water Planning
Lagan är södra Sveriges mäktigaste vattendrag. IVL har på uppdrag av Lagans Vattenvårdsförening sammanställt en skrift till föreningens 30-årsjubileum. Skriften beskriver utveckling, utnyttjande och vård av ett vattendrag genom en tidsperiod som präglats av industrialisering, stora vattenvårdande insatser och ett ökande ansvar för bevarande av våra vattenresurser. Framtida beslut om vattenvårdande åtgärder blir svårare i […]
REVERSAL OF THE EUTROPHICATION OF THE BALTIC SEA
Phosphorus and nitrogen mass balances for the Baltic Sea are presented (mainly based on data from Larsson et al. 1985) for three situations: 1) present situation, 2) after 80 % P and N removal from point sources, 3) in natural conditions. The balances indicate that a phosphorus removal from point sources will lead to a […]
PHOSPHORUS REMOVAL FROM WASTEWATERS BY ELECTROLYSIS
P removal from wastewaters by electrolysis was examined by an experimental laboratory system. Al electrodes were applied in accordance with previous experiments to find the best conditions (pH, water flow, energy consumption) for P removal. Alternating current with a frequency of 0.0039 Hz made ”self-cleansing” of the electrodes possible and provided a favourable energy consumption […]
DENITRIFIKATION I JORDBRUKSLANDSKAPETS RINNANDE VATTEN MINSKAR KVÄVEBELASTNINGEN PÅ SVENSKA KUSTVATTEN / Denitrification in Rivers Draining Arable Land Decreases the Nitrogen Loading in Swedish Coastal Waters
Nitrogen transport in three South Swedish rivers was compared with the amount of nitrogen drained to the rivers from the surrounding arable land, using mass balance calculation. It was found that as much as 25-30 % of the nitrogen is denitrified during the transport in the rivers. Denitrification may be an important process for decreasing […]
GYNNAR VISSA RÖRLEDNINGSMATERIAL VIDHÄFTNING OCH TILLVÄXT AV BAKTERIER I DRICKSVATTEN? / Do Some Tubing Materials Favour Attachment and Growth of Bacteria in Drinking Water Systems?
Bacteria attach and grow on surfaces in all biologically active systems. Municipal drinking water represents such a system. It can be questioned if desinfectants are active against bacteria growing on surfaces in the same order as against free-living bacteria. What will happen if patogenic bacteria for some reason occupy a niche amongst the surface living […]
BERÄKNING AV UTTRANSPORTERAD FÖRORENINGSMÄNGD VIA DAGVATTENSYSTEM / Calculation of mass transport of pollutants via storm water discharge
The National Swedish Environmental Protection Board recommends a standard value method for calculation of mass transport of pollutants via storm water sewer systems. In this paper mass transport calculations based on this method are compared with actual measurements. Measurements during one and a half years in the city of Lund show high amounts of leakage […]
A SIMPLE METHOD TO PREDICT THE TIME REQUIRED TO REACIDIFY A LIMED LAKE
A simple nomograph for determining the time required to reacidify a limed lake to pH 6 has been made with the reacidification model developed at the Department of Chemical Engineering, The Lund Institute of Technology. It predicts the reacidification as a function of the hydraulic residence time, the amount calcite on the bottom and the […]