WATER RESOURCES MANAGEMENT IN URBAN AREAS – An Ecosystems Approach
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, […]
pH-ELEKTROD MED ÖPPEN FLÖDESZON / pH-electrode with Free-flowing Junction
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 […]
RAPID BIOFILM DEVELOPMENT IN DEEP GROUND WATER BY GALLIONELLA FERRUGINEA
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 […]
NITRIFIKATION OCH NITRIFIKATIONSHÄMNING I SAMBAND MED BOD-ANALYS, Nitrification and Inhibition of Nitrification in the BOD Test
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 […]
KONSEKVENSANALYS AV ENHETSÖVERBYGGNAD EXEMPEL FRÅN GLASBERGET I MÖLNDAL / Consequence Analysis of the Unit Superstructure
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 […]
ÖVERSIKTLIG VATTENRESURSRÄKENSKAP FÖR MOTALA STRÖMS FLODOMRÅDE – ETT FÖRSÖK TILL REGIONAL PROFILERING / Regional Pattern of Macro-scale Water Supply/Demand Profiles in Motala River Basin- A Hydrological Study
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 […]
SYNPUNKTER PÅ KARL DUNKERS METOD FÖR UPPARBETNING AV REGN- OCH BEVATTNINGSVATTEN / Remarks Concerning Karl Dunkers’s Method of Treating Rainwater and Irrigation Water
The method developed by Karl Dunkers for collection, storage, and conservation of rainwater provides a means whereby drinking water can be economically produced in areas where traditional techniques are insufficient because of scarce water resources. This method has great potential for development and can be modified and adjusted in several ways for use in different […]
THE OCTANOL/WATER PARTITION COEFFICIENT OF HUMIC MATERIAL AND ITS DEPENDENCE ON HYDROGEN ION ACTIVITY
The octanol/water partition coefficient of three types of humic material was shown to increase with an increase in the hydrogen ion activity in the range of pH 6.5 to pH 3.5. These results suggest that a lowering of the pH of fresh waters may mobilize otherwise unavailable and potentially toxic humic compounds.
INFILTRATION AND RAINFALL – RUNOFF RELATIONSHIPS IN A SMALL CATCHMENT IN NORTHERN TUNISIA
Infiltration plays a major role in calculations of runoff and of the amount of water available for percolation to the ground water. This paper presents and discusses two aspects of infiltration: measured infiltration capacity and infiltration derived from rainfall-runoff relations. The measured infiltration capacity, which can be said to correspond to the infiltration of ponded […]
HYDROLOGISKA PROBLEM I SAMBAND MED VATTENUTNYTTJANDE I TUNISIEN / Hydrological problems in connection with water exploitation in Tunisia
Tunisia is a country which for its economical expansion is totally dependent upon its capability to develop and manage potential water resources. Irrigation requirements are competing with the demands caused by industrialization and a fast urbanization. Development of potential water resources is aggravated by the high temporal and spatial variability of rainfall and a frequent […]