Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2015. / The integrity of natural air has been compromised due to the deposition of chemical, biological and particulate substances from natural and anthropogenic sources. Adverse health consequences arising from the exposure of plants, animals and human to elevated atmospheric concentrations have been reported severally. The ambient baseline levels of many air contaminants in urban and industrial layouts of many Africa cities, especially Zimbabwe have not been fully characterized. Information on levels of these contaminants and their real time variability is therefore scarce and scanty. In this study, the ambient air concentration levels of selected gaseous pollutants in the vicinity of a fertilizer production facility in Zimbabwe were investigated. Nine sampling stations were systematically and randomly identified for the measurement of selected air pollutants (SO2, NO2, and NH3) the fertilizer production factory to capture air quality data on all wind directions. The electrochemical Drager Sensors which rely on electrochemical measuring transducer for measuring concentration of gases under atmospheric conditions was used for the measurement of NH3, SO2, and NO2. The ambient air monitored was allowed to diffuse through a membrane into the sensor liquid electrolytes, containing a sensing electrode, a counter electrode, a reference electrode, and an electronic potentiostat-circuit which ensures constant electrical voltage between the sensing electrode and the reference electrode. The flow of electrons, generated by the reaction is proportional to the concentration of the measured gas. The observed concentrations of NH3, SO2, and NO2 measured within and around the study site were very variable. Levels of NH3 ranged between 0.36 - 7.36 ppm; corresponding values for SO2 and NO2 were 0.02 - 84.61 ppm and 0.61 - 34.78 ppm respectively. These concentrations were significantly higher (p < 0.05) than measured (NH3; 0.01 - 0.05 ppm: SO2; 0.03 - 0.18 ppm: NO2; 0.17 - 1.30 ppm) at the control sampling station about 5 km from the industry. Isokinetic and dissipation of the measured gases, governed by the processes of molecular diffusion and convection, confirmed a common pattern of distance dissipation. Thus, the cloud concentrations of NH3, SO2, and NO2 within the facility were higher than observed distances away from the fertilizer factory. / Zimbabwe Presidential Scholarship

Human activities such as urbanisation, sewage treatment, industrialisation and agriculture represent major human interference in water resources. The water resources are affected both quantitatively as well as qualitatively by these activities. The impact of human interference in the Mukuvisi River catchment hydrology was studied by determining the concentration values of eight selected physico - chemical and biological parameters. These are pH, temperature, total nitrates, total phosphates, Dissolved Oxygen, Biological Oxygen Demand, lead, copper and Total Faecal Coliform Count. Seven sites were sampled along the river, from up the river in Mukuvisi woodlands up to the point where the river discharges into Lake Chivero. Analysis of the results obtained was undertaken using SPSS (paired sample T test) and descriptive graphs were drawn using Microsoft Excel 2010. Nitrates, phosphates, copper, lead and Total Faecal Coliform Counts were found to be higher than the Zimbabwe National Water Authority (ZINWA) maximum and World Health Organisation, 2011 (WHO) permissible standards from site 3 to site 7. Site 6 recorded the highest concentrations of all the measured parameters, except for pH and Dissolved Oxygen. Mean DO and BOD concentrations were 2.53 mg/l and 40 mg/l respectively at site 6. Mean total nitrates were 17.5 mg/l at site 6 above the ZINWA and WHO threshold of 10 mg/l. Site 6 also recorded a mean total phosphate of 5.9 mg/l which was above the ZINWA and WHO threshold of 0.5 mg/l. Mean TFCC was 992.6 mpn100ml-1 higher than the threshold of nil according to ZINWA and WHO threshold. Site 3 recorded the mean DO and TFCC of 2.4 mg/l and 2.80 mpn100ml-1 respectively. Site 2 had the lowest mean TFCC concentrations of 2.80 mpn100ml-1, which did not differ significantly from the WHO and ZINWA threshold of nil at p<0.05. The quality of water in the river varied from site to site in direct relation to the intensity and type of human activities along the river course. Levels of all the water quality indicators increased after discharge from the Firle sewage treatment plant at site 6 with the exception of temperature and pH. Sewage effluents, agricultural runoff and industrial effluents were found to be responsible for the high nutrient levels and high metal concentrations in the river which in turn reduced DO levels and increased BOD / College of Agriculture and Environmental Sciences / M. Sc. (Environmental Science)

MENVSC / Department of Ecology and Resource Management / Solid waste management (SWM) has become an issue of increasing worldwide concern as urban populations continue to rise and consumption patterns change. The health and environmental effects associated with SWM are escalating, predominantly in the perspective of developing countries. The rise in rural-urban migration rates in developing countries has left local authorities overwhelmed and failing to cope with the increase in solid waste. This has led to a shift from conventional systems of solid waste management to contemporary systems such as community based solid waste management (CBSWM). Despite the shift, it seems local authorities in developing countries still fail to manage suburban waste effectively. This study investigated the performance of a CBSWM scheme in Nkulumane, a high-density suburb in Bulawayo. Both quantitative and qualitative data were collected, hence a mixed methods approach employed. The study incorporated systematic sampling and purposive sampling in the selection of research participants. Data was collected through qualitative questionnaires, semi structured interviews and field observations. Thematic content analysis and descriptive statistics from SPSS version 25 were used in data analysis. The study revealed that community members from Nkulumane had sound knowledge on what CBSWM entails, however the community members had negative attitude towards CBSWM and traditional notions on SWM had an influence of their perception of CBSWM concepts. The study also revealed that Bulawayo City Council had managed to create employment for the community through a CBSWM scheme. Furthermore, operating expenses of the city council had decreased over the years. The level of environmental awareness had improved in the study area as well. However, Bulawayo City Council has battled with community participation problems, financial constraints and inter-institutional infighting. This study provides a comprehensive report on the performance of the CBSWM scheme in Nkulumane high density suburb, Bulawayo, Zimbabwe. / NRF

Landfills have served as the major sites for waste disposal in both developed and developing countries. Upon closure of a landfill site, the surface could be converted to a golf course, recreation park, playground, animal refuge, tennis court and industrial site. Even when closed, landfills still have the potential to contaminate the surrounding environment as a result of the migration of leachate from decomposing waste contained in the site. This study focused on assessing the impacts of a closed landfill on soils and plants at Lumberstewart closed landfill site in Bulawayo, Zimbabwe. Soil samples were collected at three different depths (0-30 cm, 30 - 60 cm and 60-90 cm) at the landfill and a control site. The soil samples were analysed for their texture, pH, electrical conductivity, organic matter content, cation exchange capacity and concentrations of Cd, Cu, Cr, Fe, Ni and Zn. Samples of jimson weed and pigweed growing at the closed landfill and the control site were collected from the same sites where soil samples were collected, and the concentrations of the same set of heavy metals in these weeds determined. Soil samples were digested using EPA method 3050B: Acid Digestion of Sediments, Sludge and soils whereas nitric acid and hydrogen peroxide was used for digestion of plant samples. Both plant and soil digests were analyzed for heavy metals concentrations using Flame Atomic Absorption Spectrometry (AAS). Soils from the landfill as well as the control site had a high content of sand with soil pH values which were alkaline. The electrical conductivity values of the soil samples were relatively low ranging from 0.39 to 1.67 dS/m, indicating low levels of salts in soils at the landfill. The concentrations of heavy metals at the closed landfill site were higher than the control site. Heavy metals concentrations in soils at the closed landfill followed the order Fe>Zn>Cu>Cr>Ni>Cd. Results indicated that Fe was exceptionally higher than the other metals with concentration values averaging 45690±17255 mg/kg. Cadmium on the other hand had the least concentration with values of 0.01±0.00 mg/kg. Values of Enrichment Factors of heavy metals around the soil at different depths indicated that the enrichment of heavy metals increased with depth at the landfill up to 30-60 cm after which a decrease was observed. Values for heavy metal Contamination Factor of soils around the landfill ranged from low concentration (CF<1) to very high concentration (CF>6). The Pollution Load Index (PLI) values for the soil at the Lumberstewart landfill indicated that all sites were polluted (PLI>1). Site 6 had significantly higher mean concentration of heavy metals in soils at the landfill whereas site 11 had the least. The concentrations of Cd and Ni in soils at the landfill were below permissible limits of South African National Norms and Standards (NNS) as prescribed by NEMA (2008) in South Africa whereas Cr, Cu and Zn in soils were above the NNS permissible limits. Heavy metal concentrations in soils at the landfill were above World Health (WHO) permissible limits except for Cd which was equal (0.01 mg/kg) to the permissible values of Cd in the soils at sites 5, 8, 9, 10, 11 and 12. Mean concentrations of heavy metals in jimson weed and pigweed were in the order Fe>Zn>Cu>Cr>Ni>Cd. The concentrations of Cd, Cr, Cu, Fe and Zn in both plants from all sites at the landfill were significantly higher than the control site. Heavy metal transfer coefficient for both plants indicated that heavy metal uptake was more species dependent than soil heavy metal concentration dependent. The results from this research indicate that though the Lumberstewart Landfill has been closed, it is still affecting the soils in the vicinity of the landfill. Plants and water around the Lumberstewart closed landfill could be at risk from heavy metal contamination. High concentrations of heavy metals observed in the soil could present a health risk to communities should they decide to use the landfill site for arable purposes. / Environmental Sciences / M. Sc. (Environmental Science)