ETD Collection

Permanent URI for this collectionhttps://wiredspace.wits.ac.za/handle/10539/104


Please note: Digitised content is made available at the best possible quality range, taking into consideration file size and the condition of the original item. These restrictions may sometimes affect the quality of the final published item. For queries regarding content of ETD collection please contact IR specialists by email : IR specialists or Tel : 011 717 4652 / 1954

Follow the link below for important information about Electronic Theses and Dissertations (ETD)

Library Guide about ETD

Browse

Filters

1996 - 199912010 - 20151

Settings

Has files: YesSubject: search.filters.subject.Sedimentation

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    A study of stormwater runoff from Alexandra township in the juskei river
    (1996) Campbell, Linda Anne
    South Africa, like many other developing countries, is faced with rapid urbanisation with the associated increase in the pollution load. Much of this pollution is destined for our watercourses, that eventually run into storage reservoirs which may be used for drinking water or recreational purposes. This pollution is usually attributed to human waste products which include nitrogenous wastes, phosphates, microorganisms, organic material and litter, A 6km stretch of the Jukskei river just downstream of Alexandra Township, was used to determine the different biological, physical and chemical processes that pollutants undergo during natural assimilation, their rates and efficiencies of assimilation in rivers and their impact Oil the environment downstream of the urban area. "Grab" samples were taken over a period which included both low-flow and storm events. Due to the high concentration of nutrients in the run-off from Alexandra Township, the major changes seen were in the biological conversion of organic nitrogen compounds and ammonia to nitrates, in the BOD and in the concentration of dissolved oxygen in the river, with lows of 1.1 to 1.5 mg/l 02 being recorded at Alexandra. A rapid rise in the concentration of faecal coliforms has been seen with a high of 31 million/100 ml being recorded at Alexandra in September, 1994. Sedimentation at the Alexandra site is also a common occurrence with a lot of adsorbed pollutants being effectively removed from the water column with the suspended solids. The QUAL2E water quality model, used by the EPA in the United States, was used to model the reactions that the nutrients, BOD and DO undergo. BOD and DO were modelled very well with r of 0.98 and 0.94 being calculated respectively. QUAL2E did not model tile dissolved potlutants, dissolved phosphorus and ammonia very well with the observed results showing a greater reduction ill these pollutants. A method by which these pollutants adhere to SS and settle out was
  • No Thumbnail Available
    Item
    The sedimentology and uranium mineralization of the Beaufort Group in the Beaufort-West - Fraserburg - Merweville Area, Cape Province
    (2015-07-02) Kubler, Markus
    The sediments of the lower part of the Beaufort Group (Permian) consist of mudstones, siltstones, fine- to very Fine-grained sandstones and small amounts of intraformational conglomerate. The mudstones are generally a brownish-purple colour, and are massive. The siltstones are generally greyish-green coloured, and are sometimes ripple cross-laminated. The sandstones vary in colour from green to grey. horizontally-bedded, trough cross bedded and ripple cross-laminated sandstone subfacies were recognized. All the sandstones found in the area studied may be described as fine- to very fine-grained, moderately sorted, arkosic wackes. The stratigraphic interval studied was found to have a Thickness of about 850 m. No readily mappable subdivisions were found. The sandstone to stltstone and mudstone ratio for the stratigraphic interval is about 1:4.