Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 4 uppsatser.

Ph.d.-afhandling. Danmarks Tekniske Universitet, 2006. / Haves også i trykt udg. Thesis (Ph.D.). 11 ill., 6 tables; approx. 260 ref. Summaries (Da, En).

published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

The Lusushwana River, which is within the Maputo River Basin, forms the western boundary of Matsapha, the most industrialized town in Swaziland. Current findings suggest that the Lusushwana River is polluted by industries within the town. What is not clear is the establishment of an association between the industries and the river quality, the extent of pollution in the river, and whether the river can meet national water quality objectives. Further, literature implies that the pollution causes impacts on the riverine ecosystem, health and livelihoods of the riparian communities; and that environmental monitoring, application and enforcement of legislation are weak. There is therefore a need for a detailed investigation on the pollution of the Lusushwana River to establish whether there is an association between the industries and the river quality; and the health and livelihoods impacts on the riparian communities and riverine ecosystem, with a view to recommending intervention measures to minimize the pollution taking into account social, technical, environmental, financial and institutional factors. The research was carried out at Matsapha, Swaziland. A mixed research methodology was adopted, which enabled the researcher to employ multiple data collection methods, which in turn provided the opportunity for data triangulation and as such enhanced the study‘s rigour, validity and reliability. The research took a deductive approach, and entailed a longitudinal experimental and cross-sectional survey design. Non-probability sampling methods in the form of snowball and purposive sampling were used to select an appropriate and representative sample that can be generalized. Data were collected using technical experiments, biotic index, semi-structured open ended questionnaires, interviews, and field observations. The questionnaires were self administered to 121 riparian communities‘ households, 3 environmental monitoring agencies and 26 proprietors of companies at Matsapha. Additionally, 15 key informants were interviewed. Water and wastewater samples were taken along the Lusushwana River, and at the wastewater treatment plant and industries. Statistical analysis of the data using PASW Statistics and Microsoft Excel led to the various findings from the research. The findings confirm the claim from literature that the anthropogenic activities at Matsapha pollute the Lusushwana River. The evaluation of the Lusushwana River showed microbiological, physical, organic and inorganic pollution to be most acute; but concentrations of heavy metals such as cadmium were low. The biotic index showed the absence of macro-invertebrate species (e.g. damselflies) that are highly sensitive to oxygen-depletion pollution. The riparian communities suffer human health impacts, especially diarrhoea and skin problems, and are restricted in meeting their domestic and livelihood water needs by the quality of the Lusushwana River. This study has led to the conclusion that the Lusushwana River is polluted by the anthropogenic companies in the Matsapha industrial estate, but has revealed that there is also pollution upstream of Matsapha. The companies at Matsapha have environmental management procedures that are insufficient or ineffective; environmental awareness, education, monitoring and legislation enforcement is lacking, the riparian communities suffer health and livelihood impacts, and their complaints are not effectively addressed. Therefore the study recommends that effective monitoring, legislation enforcement, and collaboration of all stakeholders should be used to achieve effective wastewater management and to minimize pollution of the Lusushwana River and the associated impacts. The empirical findings of the study regarding the pollution of the Lusushwana River and its impacts on the riparian communities, as well as the need for effective monitoring, enforcement of legislation and collaboration of the stakeholders contribute to professional knowledge, academic research, policy and practice. Potential areas recommended for further research include studies on assessment of companies that need pre-treatment in order to minimize environmentally significant discharges into the Lusushwana River; and on how much pollution the river can receive and still meet national water quality objectives.

M. Tech. Chemical Engineering. / Discusses the HybridICE filter as a new but economical device for separating the ice from the slurry in freeze desalination processes. There is no direct information in the literature on the filter so there is a need to describe the principles behind the operation. There is also a need to investigate the filtering process in order to increase yield and purity of the ice produced. No design method exists for the filter. A design method has to be established so that when the required flow-rate is determined, the dimensions of the filter can be calculated.

M. Tech. Chemistry. / Objectives of this study was to assess the levels of heavy metals in bovine meat, hair, sediment, peat and water from the study areas using ICP-MS and internal standard calibration.The specific objectives are to: collect hair and meat of impala and cattle, sediment, peat, soil and water samples; digest samples; determine the level of some of the following heavy metals Cd, Cr, Cu, Hg, Mn, Pb, Sr, U, V depending on the background information on the above samples; compare the levels of Hg in sediment and peat using ICP-MS and Zeeman mercury spectrometer; determine the limit of detection of trace elements in different matrices using ICP-MS; establish correlations among concentrations of heavy metals in specified samples.

published_or_final_version / Public Administration / Master / Master of Social Sciences

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

Metabolic were used to evaluate Enterococcus as an indicator of faecal pollution. Enterococci were isolated using m-Enterococcus agar and speciated using conventional biochemical tests. Forty percent of the isolates were identified and metabolically characterized by the automated Biolog system. The biochemical test scheme recognized 16 enterococcal species, while Biolog recognized nine. Both methods identified E. faecalis at the greatest frequency. Overall species frequencies varied between the two methods. Biolog was unable to identify 31% of the isolates; 7% of the isolates were unidentified by the biochemical test scheme. Of the identified isolates, metabolic profiling with Biolog achieved speciation with 60 substrates. Unique profiles were obtained for 89% of the isolates. Isolates also demonstrated inter-trial differntial metabolism of substrates. This and the large number of unidentified isolates suggest great diversity among enterococci. Diversity and inter-trial metabolic inconsistencies will complicate use of enterococcal metabolic profiles as a source-tracking tool. / xxiii, 264 leaves ; 29 cm.