Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Environmental Health, Technikon Natal, 2001. / The debate surrounding mercury pollution of the river system below Thor Chemicals in Kwa Zulu Natal, South Africa has been of concern to the people of the region for several years. No scientific assessment of Mercury pollution has been carried out to date, other then a study conducted by Johnston et al. (1991) in 1990 in an area restricted to within 5 kilometres of the plant. Due to elevated levels being detected directly below the plant, Johnston et al. (1991) have expressed concern that this could result in the mobilisation of Mercury into the ecosystem and possibly threaten the Ecology of the Inanda Dam which is located approximately 20 kilometres south of Thor Chemicals which is a major reservoir for Durban. Added to this, the community residing in the area has expressed a great deal of concern and the matter was taken up in parliament in 1998. These factors provide impetus for a follow up study to determine the extent of mercury transformation into the higher trophic levels in the area surrounding Thor Chemicals. In order to quantify the extent to which mercury has become mobilised in the ecosystem and to identify possible pathways of exposure to the community, samples of sediment, algae, cattle hair and fish were taken at ten sample sites. These sample sites were selected at intervals along the Mngceweni and Umgeni River. The first sampling site was situated below Thor and the final sample site was located at the head of the Inanda Dam. Sediment, algae, cattle hair and fish were specifically chosen as they are considered to be reliable indicators of mercury pollution and mobilization. Fish,form an important part of the diet of the community residing in the study area. Mercury concentrations for the above parameters, were compared to mercury concentrations found in the control area, upstream from Thor, as well as to international and local standards. Composite sediment samples taken at the first sample site, within 500 metres of Thor Chemicals, revealed a mercury level of 54j.lg/gram. Mercury concentrations detected in the remainder of the composite sediment samples were significantly lower and revealed similar levels of magnitude throughout the rest of the study area. The higher concentration of mercury in the sediment at the site directly below Thor Chemicals may be attributed to a high / M

M.Sc. (Zoology) / Please refer to full text to view abstract

M.Sc. / Please refer to full text to view abstract

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2008 / The lower Diep River is a major freshwater ecosystem in the Western Cape. The river is surrounded by many possible sources of metal pollution such as an oil refinery, industries, a sewage treatment plant and a landfill site. However, metal contamination levels have not been monitored in this river. The aim of the study was therefore to monitor the degree of metal pollution in the lower Diep River, over a period of one year, and to investigate the use of the sedge Bolboschoenus maritimus, as biomonitor species. Three sampling sites were used. Site I was located in the vicinity of landfill sites and farm areas. Site 2 was located I km upstream from a wetland reserve, surrounded by heavy industrial activity and continuous residential developments. Site 3 was located downstream of the wetland reserve, 2 km from the river mouth. The following metals were investigated: aluminium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. Water and sediment samples were collected every two months for a period of one year. Plant specimens (roots, leaves and stems) were collected seasonally from site I and site 3. Samples were acid digested and metal analysis was done using an ICP - AES (Inductively Coupled Plasma- Atomic Emission Spectrophotometer). Statistical analyses were done to investigate possible differences between the sites, sampling occasions and various plant components.

Dissertation submitted in partial fulfilment of the requirements for the degree Master of Technology: Environmental Management in the Faculty of Applied Science at the Cape Peninsula University of Technology / Greywater is domestic wastewater from daily kitchen, laundry, bath, shower, hand washing practices and does not include wastewater from the toilet. Greywater from informal settlement has been identified as important environmental pollution sources. Inadequate sanitation and poor drainage in informal settlements result in greywater being stagnant at the base of communal taps. This water has a potential to cause health problems to those who come in contact with it. Studies of greywater quality in informal settlements in South Africa tend to concentrate on physico-chemical analysis and microbial indicator organisms. In order to adequately manage greywater in informal settlements there is a need to understand the microbial pathogens present in such water. Therefore this study is aimed at determining the level of microbial contamination of stagnant greywater in the RR Section of Khayelitsha, Western Cape. Six sampling sites were identified and sampling of stagnant greywater was conducted twice a month (from January to May 2013) from the base of six communal taps, which served as the sampling sites. The microbial enumeration techniques employed in this study were the Most Probable Number (MPN) techniques, the Heterotrophic Plate Count (HPC) technique and the Flow Cytometric (FCM) technique. The API 20E and the RapID™ ONE systems were used to identify possible pathogenic Gram-negative microorganisms, while possible pathogenic Gram-positive microorganisms were identified with the BBL Crystal™ Gram Positive (GP) Identification (ID) system. The highest MPN counts were 1.6 x 108 microorganisms/100mℓ recorded at Site A (weeks 3 and 5) as well as at Site B (week 5). The corresponding highest faecal coliform count was 4.7 x 106 microorganisms/100mℓ obtained at Site B (week 5). The highest E. coli count observed was 1.8 x 106 microorganisms/100mℓ recorded at Site A (week 5) and Site F (week 5). In comparison, the highest HPC count was 2.9 x105 microorganisms/mℓ recorded at Site C in week 4. The results obtained by the MPN and HPC techniques were significantly (p < 0.05) higher than the water quality standards by Department of Water Affairs and Forestry (DWAF) (1996a; 1996b) and the SABS (2011). The highest total FCM and viable FCM counts were 3.4 x 107 microorganisms/mℓ and 3.1 x 107 microorganisms/mℓ, respectively recorded at Site A in week 5. The FCM technique displayed significantly (p < 0.05) higher results than both the MPN and HPC techniques, which highlighted its reliability in obtaining more accurate enumeration results. The RapID™ ONE and the API 20E identification systems mostly identified Escherichia coli, Klebsiella pneumonia, K. oxytoca, Acinetobacter baumannii/calcoaceticus and Enterobacter cloacae, while the organisms more commonly identified by the BBL Crystal™ Gram Positive (GP) Identification (ID) system, were the Corynebacterium species, and Bacillus cereus. The presence of these organisms raises health concern to the community of RR Section, as some are known to cause waterborne diseases, while others are known to cause nosocomial infections.

M.Sc. (Zoology) / An investigation was made into the water chemistry, bacteriology and macroinvertebrate fauna of the Elsburg Spruit and its major tributaries within the municipal boundaries of the City of Germiston. From the results obtained it is clear that the main stream and most of its tributaries are seriously affected by a combination of pollutants. Three types of pollution could largely be distinguished namely fecal bacterial contamination of parts of the stream system which may be related to the possible discharge in the stream of domestic sewage. This in turn may be a major source of organic enrichment of the water of the stream at some places. Acid pollution associated with high mineral loads and heavy metal concentrations which in the latter case could be traced to mining regions and industrial areas in the catchment area of the system. Despite the serious disturbance of stream conditions in the upper region of the Elsburg Spruit some recovery does in fact take place in the lower lying regions of the Elsburg Spruit where the stream flows for several kilometers through a natural vlei area. Certain recommendations are made concerning the location and possible elimination of the major sources of pollution.

M.Sc. (Zoology) / Please refer to full text to view abstract

M.Sc. (Zoology) / An investigation was made into the presence and uptake of seven selected metals by the organs and tissues of the various developmental stages of the African clawed frog Xenopus laevis from industrial, mine and sewerage polluted aquatic environments on the Witwatersrand. These results were compared with conditions in two relatively unpolluted localities where the clawed frog also occurs. Attention was given to the physical and chemical conditions including the concentration of the metals at various localities. Gut content analyses of the frog stages of the plataona was made to identify the particular food items ingested by the animal but also to correlate this with the incidence of the macro invertebrate organisms present. Metal concentrations were determined for both the gut contents as well as the macro invertebrates as a group at two selected localities. The presence and concentration of various metals were determined in specific organs and tissues of the frog and compared with each other. According to the data the spleen, gallbladder, middle & Hind gut as well as the testes were identified as the target organs containing the highest concentrations of the various metals. Shortcomings in the work is pointed out and recommendations made on possible further research.

M.Sc. / Victoria Lake also known as Germiston Lake is an urban impoundment which is situated east of Johannesburg. This Lake is used for a number of recreational activities and can be viewed as an important feature of this area. It is a natural perennial pan and has several inlets (inflows) which drain a part of Germiston's business area and surrounding residential areas. In the past various studies have focused on the water quality as well as other aspects of the ecology of the Lake that may influence recreational activities and the physical-chemical quality of the water. However, information on the physical-chemical quality of the inflow water is poorly investigated and needs further attention. This study gathered further data on the water quality and associated problems within the major inlets to the Lake. Six inlets were monitored monthly for a year. The water samples that have been collected were analyzed for several physical and chemical constituents. In general it seemed as if the waters of the inlets around Victoria Lake were more polluted in comparison to the surface waters of the lake Sites 1, 4 and 5 seemed to be the most polluted inlets and it should be closely monitored in future. Most of the water quality constituents that have been compared with the water quality criteria exceeded the acute effect values given by the South African Water Quality Guidelines. Waste is thus continually dumped into the Victoria Lake via the major inlets resulting in water pollution. The quality of this resource is therefore diminishing rapidly. If Victoria Lake is to be successfully used and managed in order to limit the impact on the environment, all further development and management should take place in terms of sustainable development.

Annually, the global environment receives enormous amounts of persistent organic pollutants (POPs) that include polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in addition to polycyclic aromatic hydrocarbons (PAHs). Their ubiquity has made them identifiable contaminants in almost every environmental compartment of the global system. In particular, aquatic systems have been adversely affected by these pollutants. Therefore, effective monitoring, both in ground and surface water, that can reliably assess their environmental impacts is required. Passive samplers have been proposed as suitable options to the traditional grab/spot/bottle sampling approach because they simultaneously sample, isolate and enrich target analytes. Moreover, apart from successfully detecting very low water dissolved analyte concentrations (trace and sub-trace levels), the devices can also provide time weighted average (TWA) concentrations that take into account episodic events. This is usually not practical with other sampling techniques.