Alla artiklar

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 […]

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 […]

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 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 […]

Especially in developing countries, the rapid growth of densely populated areas makes great demands upon planners and decision-makers. There is, among other things, a strong need of rational management of water resources within the framework of integrated societal planning. The complexity exhibited by large urban areas calls for a new approach in planning and management, […]

Most problems associated with pH measurement with electrodes are related to the failure of the reference half-cell to maintain constant potential. The problem is most obvious when making pH measurements on two sample solutions with a great difference in ionic strength. An example would be when a pH meter is standardized with a buffer of […]

The development of Gallionella ferruginea biofilms and the associated iron precipitation in flowing ground water from two 46 m deep wells were studied over 48 h. The bacterium formed biofilms of up to 1.76 /ìg total organic carbon per cm2 with 18.8 /ìg precipitated iron per cm2. Microscopic observations revealed multilayered net-works of the bacterium […]

The nitrification in the BOD-test at different contents of nitrification inhibiting agents has been investigated through analyzing the contents of ammonia-nitrogen, Kjeldahl-nitrogen, nitrite+nitrate-nitrogen and alkalinity before and after incubation. The tests have been made on treated sewage from Henriksdal sewage treatment plant, a plant with partial nitrification in the activated sludge process. BOD-tests have been […]

The unit superstructure is a new method of constructing superstructure in traffic areas. The system consists of macadam and a porous asphalt. The structure distributes rain and surface water by means of infiltration to the underlying soil. When used in humid areas this method may drastically reduce the need for costly drainage and storm water […]

Macro-scale water supply/demand profiles are presented for thirteen subunits of Motala river basin in south-central Sweden. The renewable water supply of each subunit is composed of exogenous inflow from the neighbouring upstream subunit, and endogenous flow production in the unit itself. The latter contains hydrochemically different water fractions, mixing in the river and emanating from […]