Dissertations / Theses on the topic 'Waste disposal in the ground Environmental aspects Victoria'

Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2014.
In this study, laboratory and greenhouse experiments were conducted to evaluate the effects of utilization of land fill leachate for irrigation purposes on potted soil and Swiss chard, to provide more insight into effects of landfill leachates on the environment. Swiss chard was grown and irrigated with different concentrations of leachates in pot experiments. For several weeks, the experimental soil and Swiss chard leaves was analyzed to assess extent of change in different chemical compositions, post-irrigation. The leachate samples had a high electrical conductivity (mean = 383 mS cm-1) and high soluble salts content (mean values, Na = 714.5 mg/L, K= 56.8 mg/L, Ca = 133.7 mg/L, Mg = 68.8 mg/L, Cl = 983 mg/L); while the composition of heavy metals in these wastewater leachates were of low concentrations. The application of leachates in irrigation resulted in increased soil cation concentrations, particularly those of Na ions (increased sodicity). Similarly, an increase in electrical conductivity and pH were recorded in the soils after irrigation with leachates. The soil metal concentrations were low and there was no significant difference in soil heavy metal concentrations between the soils irrigated with leachate and those of the controls. The results also show significant (p <0.05) reduction (up to 50%) in Swiss chard growth with application of (100%, 50% and 25%) of leachate as source of irrigation water compared to the growth observed in leachate-free (control) irrigation systems. This reduction in growth was best attributed to the high cation content in plant tissue picked up from the soil which was high in cations as a result of leachate irrigation.

Porous plates delivered calcium chloride at a negative potential to the top of blocks of partially welded (20.1 x 20.1 x 66.6 cm) and densely welded (30.1 x 20.1 x 48.1 cm) tuff with discrete fractures. During infiltration, flux increased through the partially welded block's fracture as the applied suction was lowered to 2.3 cm. The wetting front advanced 66.6 cm in 239 days. Chloride concentration and temporal moments from five tracer tests with 0 to 5 cm of applied suction indicated that preferential fracture flow occurred. Displacement transducer data reflect a decrease in fracture aperture at several months prior to but not during tracer tests. Fracture transmissivities decreased an order of magnitude (6.4 x 10⁻⁹ to 4.2 x 10⁻¹⁰ M²/s) as the applied suction increased from 0 to 5 cm while the tensiometer data indicated a suction of about 20 cm of water within the fracture and matrix. Highest during infiltration to an initially dry block, inflow losses of 3 to 44 percent due to evaporation are the greatest source of error for the constant potential method used.

С точки зрения экологизации производственных процессов перед исследователями и промышленниками, перед муниципальными властями выдвигается необходимость обеспечить максимально возможную безвредность технологических процессов и полное использование всех отходов производства, а с точки зрения экономики возникает необходимость минимизации затрат предприятия, путем ведения его эффективной налоговой политики в области землепользования, а также разработки методов стимулирования к рациональному использованию земли. Целью магистерской диссертации является разработка модели налогового поведения промышленного предприятия при размещении отходов производства на земле. Анализ основывался на рассмотрении техногенной нагрузки на земли и почвы Свердловской области, а также изучении существующих методов и инструментов управления налоговой нагрузкой промышленного предприятия в части использования земель. В качестве источников информации использовались нормативно-правовые акты РФ, база публикаций Российского индекса научного цитирования, представленная на ресурсе Elibrary, статистические данные по исследуемой тематике, данные отчетности ФНС. В ходе написания магистерской диссертации была разработана и апробирована модель налогового поведения отходопроизводителя. Использование данной модели нацелено на снижение налоговой нагрузки отходообразующего предприятия в части использования земель путем оптимизации налоговых платежей, учитывая интересы налогоплательщика и экологическую обстановку в регионе. Предложен авторский подход к совершенствованию размера платы за пользование земельным ресурсом (налог на землю, арендная плата, нормативная цена земли), в основу которого положен принцип дифференциации ставок, что обусловит внедрение технологий утилизации в целях сокращения площади занимаемых земель. В результате апробации разработанной модели был выявлен вариант эффективного налогового поведения с максимально возможной экономической выгодой.
From the point of view of greening production processes, researchers and industrialists, municipal authorities are required to ensure the maximum possible harmlessness of technological processes and the full use of all production waste, and from an economic point of view, there is a need to minimize the costs of an enterprise by maintaining its effective land use tax policy, and the development of incentive methods for the rational use of land. The purpose of the master's thesis is to develop a model of the tax behavior of an industrial enterprise when disposing of production waste on the ground. The analysis was based on the consideration of the technogenic load on the land and soil of the Sverdlovsk region, as well as the study of the existing methods and tools for managing the tax burden of an industrial enterprise in terms of land use. The sources of information were the regulatory legal acts of the Russian Federation, the database of publications of the Russian Science Citation Index, presented on the Elibrary resource, statistical data on the subject under study, and data from the FTS reporting.. In the course of writing the master's thesis, a model of tax evacuation behavior was developed and tested. The use of this model is aimed at reducing the tax burden of the waste- forming enterprise in terms of land use by optimizing tax payments, taking into account the interests of the taxpayer and the environmental situation in the region. An author's approach is proposed to improve the size of payment for the use of land (land tax, rent, normative price of land), which is based on the principle of differentiation of rates, which will lead to the introduction of recycling technologies in order to reduce the area of land occupied. As a result of testing the developed model, a variant of effective tax behavior with the greatest possible economic benefit was identified.

A high level of plant mortality on the Bisasar Road landfill, Durban, South Africa initiated an investigation into the primary causes of the mortalities and a search for potentially tolerant plant species. Field studies revealed that volunteer grass growth on cover soils was primarily limited by elevated soil C02, with high soil conductivity and low soil moisture possibly compounding the effect. Cynodon dactylon, the most abundant coloniser of the site appeared to be relatively sensitive to high soil CO2, whilst less common species such as Sporobolis cifricanus and Paspalum Paspoloides appeared to be less sensitive. Further research focused on the high mortality of trees planted on the landfill providing insight into the important variables limiting survival· and the relative differences in performance of 20 tree species. A more rigorous 14-month field experiment was designed and constructed, to assess the performance of 10 of the more promising tree species, the environmental conditions limiting tree growth and the benefit of a deeper layer of better quality topsoil. Some species, such as Barringtonia racemosa, performed relatively well in the field experiment, whilst other species such as Syzygium cordatum, and Harpephyllum caffrom experienced high mortalities and poor growth. The better quality topsoil layer provided little improvement in the performance of the stronger or the weaker species, however significant improvements were recorded for species with relatively intermediate performance. The composition of the soil atmosphere was shown to determine rooting depth. Species that performed better had deeper roots, possibly assisting them in utilising deeper soil moisture reserves. It was concluded that high soil CO2 and low soil O2 levels were the key variables responsible for poor tree survival and growth in this field experiment. A soil fumigation system was designed to provide more control of soil gas concentrations and to experimentally investigate differential species responses and the relative effects of soil CO2 and O2 on tree survival and growth. The apparatus fumigated, for a period of 140 days, the rhizosphere of 80 potted 'tolerant' (Barringtonia racemosa) and 'non tolerant' (Harpephyllum caffrum) trees with 4 treatments consisting of varying combinations of CO2 and 02. The difference in performance of Barringtonia racemosa and Harpephyllum caffrum in the experiment on the landfill was similar to that of the elevated CO2 low O2 fumigation treatment, supporting the premise that landfill gas was the key cause for poor performance of plants. Reduced stomatal conductance and resultant limitations on photosynthesis were found to be indicative of species sensitivity. Low O2 had an additive effect on the impact of elevated CO2 in Harpephyllum caffrum however, even with normal soil O2 levels, 25% soil CO2 had negative growth effects on this sensitive species. Maintenance of plant health and better performance of Barringtonia was attributed to a high inherent level of tissue porosity and aerenchyma. The research provided a greater understanding of the causes of poor vegetation growth and the possible mechanisms of species tolerance to landfill conditions.
Thesis (Ph.D.)-University of Natal, Durban, 2003.

The deep row trenching of ventilated improved pit-latrine (VIP) and waste water treatment works (WWTW) sludge is a unique alternative cost effective land application method that will prevent odour and health problems and may permit higher application rates than surface application. The goal of this research is to assess the environmental consequences of employing deep row incorporation of VIP and WWTW sludge to forest plantation lands for the production of Eucalyptus dunnii. The objectives are to monitor, define and quantify the fluxes of nutrients (nitrate and phosphorus) from the buried sludge to the surrounding soils, groundwater and surface water. The WWTW study was conducted on a forestry plantation located near the Shafton Karkloof Falls, about 10 km from Howick in the KwaZulu-Natal province of South Africa. The land for the research is owned by SAPPI, a timber plantation company. The trenching was done with stockpiled secondary sludge from Umgeni WWTW in Howick. VIP sludge trenching was done at the Umlazi E-ponds site in Durban owned by EThekwini Municipality. This site was formally used as a wastewater treatment plant sludge drying bed. The treatment works comprised three oxidation ponds and was operated until 1999, when it was decommissioned after a heavy flood, resulting in damage to the oxidation ponds. The sites were instrumented with wetting front detectors, piezometers and boreholes for collection and analysis of leachate from which were determined subsurface loss of nitrogen and phosphorus. Soil water status and groundwater levels were also monitored. Simulation of the process of water, nitrate and phosphorus transport was performed in order to aid the development of the sustainable management methodologies for land application and the trenching of VIP/WWTW sludge. The study focuses on the entrenched sludge to determine the concentration of pollutants, monitorchanges in concentration over time and to monitor the movement of solutes and any change taking place in the surrounding soil water and groundwater. The results contribute to the development of guidelines and protocols for VIP/WWTW sludge handling and trenching in South Africa. It was demonstrated that the nutrient migration processes can be approximated with the conceptual simplifications of the inputs to the model based on field evidence, soil survey data and applicable literature. In the study, it was found that high concentrations of nutrients were evident in the water infiltrating into and through the sludge in all trench types. The nitrate concentration median values in the trenches were 234mg/l and 36mg/l for SAPPI and Umlazi respectively, while the recorded median value for phosphorus was 1.0mg/l and 3.5mg/l for SAPPI and Umlazi respectively. However the effect of vertical seepage of nutrients, into the deep aquifer in fractured rock has not been observed in the deep borehole with the nitrate concentration median values at 5mg/l and 0.6mg/l for SAPPI and Umlazi respectively, while the phosphorus concentration median values were 0.03mg/l and 0.15mg/l for SAPPI and Umlazi sites respectively. The study revealed significant differences between the sandy alluvial site at Umlazi and the shale dolorite site at the SAPPI forests. Where an unsaturated zone below the entrenched sludge existed at the Umlazi site, nutrient transport was retarded, whereas in the shales of the SAPPI site, preferential delivery flowpaths transported high concentrations of nutrients rapidly from the entrenched sludge to the base of the hillslope. These mechanisms needed to be treated differently in the simulation exercise.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Rehabilitation of landfill sites is important for successful land utilization. Revegetation is one key element of the process since it can overcome aesthetic problems. The inimical challenges of landfill leachate and gas are largely responsible for the difficulties associated with the revegetation of completed sites. Many components of landfill leachate can be catabolized by microbial associations thereby reducing their impacts on the environment. The importance of research on interactions between pollutants, microorganisms and soil is its applicability in environmental risk assessment and impact studies of organic pollutants which enter the soil either accidentally or intentionally. The application of image analysis with microscopy techniques to landfill soil-pollution interactions provides a means to study surface microbiology directly and to investigate microbial cells under highly controlled conditions. This research focused on the development of a method to study the real time processes of attachment, establishment, growth and division of microbial cells/associations in site covering soils. Image analysis provides a powerful tool for differential quantification of microbial number, identification of morphotypes and their respective responses to microenvironment changes. This minimal disturbance technique of examining visually complex images utilizes the spatial distributions and metabolic sensitivities of microbial species. It was, therefore, used to examine hexanoic acid catabolizing species, both free-living and in a biofilm, with respect to obviating the threat of hexanoic acid to reclamation strategies. The three sources of inoculum (soil cover, soil from the landfill base liner and municipal refuse) were compared for their ability to provide associations which catabolized the substrate rapidly. During the enrichment programme the inocula were challenged with different concentrations of hexanoic acid, a common landfill intermediate. From the rates at which the substrate was catabolized conclusions were drawn on which concentration of hexanoate facilitated the fastest enrichment. The results of initial batch culture enrichments confirmed that the soil used contained microbial associations capable of catabolizing hexanoic acid at concentrations < 50mM, a key leachate component. Exposing the landfill top soil microorganisms to a progressive increase in hexanoic acid concentration ensured that catabolic populations developed which, in situ, should reduce the phytotoxic threat to plants subsequently grown on the landfill cover. The analysis of surface colonization was simplified by examining the initial growth on newly-exposed surfaces. The microbial associations generated complex images which were visually difficult to quantify. Nevertheless, the dimensional and morphological exclusions which were incorporated in the image analysis software permitted the quantification of selected components of the associations although morphology alone was inadequate to confirm identification. The effects of increasing the dilution rate and substrate concentration on the growth of surface-attached associations in Continuous Culture Microscopy Units (CCMUs) were examined. Of the five dilution rates examined the most extensive biofilm development (9.88 jum2) during the selected time period (72h) resulted at a dilution rate of 0.5h' (at 10mM hexanoic acid). The highest growth (608 microorganisms.field"1) was recorded in the presence of 50mM hexanoic acid (D = 0.5h"1). To ensure that the different morphotypes of the associations were able to multiply under the defined conditions a detailed investigation of the component morphotypes was made. Numerically, after 60h of open culture cultivation in the presence of 50mM hexanoic acid, rods were the predominant bacterial morphotypes (43.74 field'1) in the biofilms. Both rods and cocci were distributed throughout the CCMUs whereas the less numerous fungal hyphae (0.25 field'1) were concentrated near the effluent port. The specific growth rates of the surface-attached associations and the component morphotypes were determined by area (//m2) colonized and number of microorganisms.field"' and compared to aerobic planktonic landfill associations. From area determinations ( > 0.16 h'1) and the number of microorganisms.field"1 10mM hexanoic acid was found to support the highest specific growth rate ( > 0.05 h"1) of the surfaceattached association isolated from municipal refuse. With optical density determinations, the highest specific growth rate (0.01 h'1) was recorded with 25mM hexanoic acid. The surface-attached microbial associations component species determinations by area and number showed that the hyphae had the highest specific growth rate ( > 0.11 h"1). The surface-attached microbial association specific growth rate determinations from the discriminated phase (0.023 h'1), area colonized (0.023 h"1) and number of microorganisms (0.027 h"1) calculated from the results of the component species rather than the association should give more accurate results. The specific growth rate obtained differed depending on the method of determination. Any one of these may be the "correct" answer under the cultivation conditions. Depending on the state (thickness) of the association (free-living, monolayer or thick biofilm) the different monitoring methods may be employed to determine the growth. As a consequence of the results of this study, the kinetics of microbial colonization of surfaces in situ may be subjected to the same degree of mathematical analysis as the kinetics of homogeneous cultures. This type of analysis is needed if quantitative studies of microbial growth are to be extended to surfaces in various natural and artificial environments.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

Municipal Solid Waste generation has become an inevitable consequence of lifestyles and daily living. However, the nature (quantity and quality) of this waste stream can vary and is largely dependent upon the manner in which waste production is managed, by both government and the public. The increasing practices of littering, dumping and burning of solid waste by households (and industries though not extensively dealt with in this study) in South Africa has led to the finding that municipal solid waste is being irresponsibly managed. In this regard, it becomes necessary to investigate the attitudes and behaviour of individuals and households toward solid waste practices, which further include mitigating measures such as reduction, reuse and recycling for the generation of solid waste. The role of the South African government in providing a refuse removal and safe disposal service to all citizens is suggestive of the responsible role of government to ensure that solid waste is being effectively managed by all sectors of society. The aims of this study in light of the above were to review the municipal solid waste policies and strategies of local government authorities in South Africa, highlighting the shortcomings and discrepancies that exist between legislative policies and actual management practices; which is also reflective of the attitudes and approaches to solid waste management by households. This was achieved by focusing on the case study of the Msunduzi Municipality and included investigations into socio-economic and cultural influences on solid waste disposal practices. The objectives of the study were achieved by means of a questionnaire survey that elicited specific responses from 650 sampled households in five suburbs of differing socio-economic status. A further analysis to identify the nature of household municipal solid waste for landfilling from three suburbs of differing socio-economic status was conducted by categorizing 25 tons of garbage at the New England Road Landfill Site, leading to inferences about consumer purchasing power and disposal practices. Further, key personnel in the Msunduzi Municipality’s waste management division were interviewed to ascertain the solid waste challenges faced at local municipal and national levels of government. The study revealed several significant findings of which the most important is that the implementation of South Africa’s national municipal solid waste legislation policies and strategies are inconsistent with local government practices and procedures; thus compromising equity, efficiency, effectiveness and the sustainability of municipal solid waste disposal. Factors contributing to this are shown to be inadequate management and service delivery. The research has shown that monitoring and control systems which purported to ensure environmental sustainability are lacking and inadequately address issues where the implementation of municipal solid waste regulations are in contravention with national solid waste policies. The outcomes of the questionnaire survey and the assessment of household municipal solid waste for landfilling reveal that socio-economic status and culture do in fact influence the nature of solid waste and the disposal methods used by residents. The receptiveness of households towards adopting suggested municipal solid waste disposal practices was also investigated. The non-compliance of residents with municipal solid waste legislation and policies points towards a lack of monitoring and control measures, thereby not providing for a sustained and adequate service delivery which is environmentally sound. The research further suggests that all sectors of the South African public and the government are inadequately informed in terms of aspects of municipal solid waste. This has led the researcher to recommend that further education and awareness campaigns and its role in environmental sustainability are needed so that a sharing of responsibility between government and the public can be effected to aid municipal solid waste management in the country. It is argued that the insight into the roles of socio-economic status and cultural influences over solid waste practices provide a platform from which municipal authorities can work to specifically address the problems associated with municipal solid waste at a community level. It is the task of the national government to ensure that South Africa’s municipal solid waste is being responsibly managed at the local municipal levels so that the health and safety of the environment and its citizens are suitably addressed, hence the focusing on solid waste legislation and national policies (which have been recognized internationally as being environmentally sound and sustainable) must be translated in terms that local municipalities can adopt, assuming that they have been sufficiently empowered in terms of both knowledge and adequate budgeting.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

This study investigated the establishment of vegetation cover planted in plug and seedling form in the closure phases of the Umlazi Landfill. It also investigated the various facets of the closure process of the Umlazi Landfill and the effect these have on the establishment and choice of vegetative cover, and the grass technology used to make the establishment of vegetation a success. The setting up of trials and the gathering of basic data were undertaken to assess the alternative vegetation options available to researchers. The cover provided by the grasses was assessed in the investigation. The capping of landfill sites is a relatively new approach and it is soon to become a mandatory requirement by the Department of Water Affairs and Forestry (Minimum Requirements for Waste Disposal) (DWAF, 1998). This systematic investigation used in the closure of the Umlazi Landfill, will provide a model for the capping of landfills in South Africa. Seeing that this was the first hazardous (H:h) landfill site in the country to be closed according to the Minimum Requirements for Waste Disposal (DWAF, 1998), every attempt was made to ensure that all aspects in the closure of the site met with the Minimum Requirements. The Minimum Requirements document mentions only briefly that the landfill must be vegetated with some grass type. Prior to 1994, capped landfill sites were usually planted with traditional grass seed mixes and these were not widely successful, as seen on many older landfills that have been partially or completely capped, and where vegetation cover is sparse. There is much literature in the developed countries on the closure of landfills (e.g., Erickson, During the site inspections in June 2001 and February 2002, it was noted that many species of alien plants had established themselves in the poor soil conditions. This made it even more important to find indigenous vegetation to vigorously establish itself that would prevent the establishment of alien invaders. Samples of grass species established on some part of the site were also taken for identification. The dominant grass was identified as Cynodon dactylon. In view of establishing a balanced vegetative cover on top of the Umlazi Landfill, Acacia karoo trees (in seedling form) were also planted. Three bunch grass species, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, were tested to see if thatching grass could be grown on the site to generate a cash crop for local residents of Umlazi township. Preparation and planting of the capped areas took place in the latter part of 2003 and were completed in early 2004. Measurements and field data were recorded and statistically analysed. The trials revealed three key findings: Firstly, both creeping grasses studied, namely Cynodon dactylon var. “Sea Green” and Panicum natalense var. ”Natal Buffalo Grass” grew well on the site. Initially P. natalense grew faster but after a month, C. dactylon overtook it. At the end of the trial (six months, P. natalense provided a higher level of soil cover. However, C. dactylon grew more consistently over this period. Hence both species provided good growth and cover on this site. Secondly the three bunch grasses, Melinis nerviglumis, Melinis minutiflora and Hyparrhenia hirta, all grew well and had similar survival rates. Hence the potential for growing these grasses as a cash crop has potential. Thirdly, all the Acacia karoo trees survived, i.e., they achieved 100% survival. The average height increase and stem width was similar in all trials and growth was consistent over the six month growing period. Hence the tree species would be a good choice for planting on landfills in its ecologically suitable zones. It is therefore feasible to envisage the planting of a mixture of grasses under the cover of A. karoo trees, to provide a balanced mixture of indigenous grasses to cover a freshly capped landfill. Such a system should provide for stable growth of vegetation for many years.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008

Integrated management of municipal and hazardous waste is one of the challenges facing the new municipalities in South Africa, especially those located in previously disadvantaged rural areas. However, much of the research on solid and hazardous waste management in South Africa has examined waste management problematics in urban areas, the majority of which are located within the jurisdiction of local governments which are comparatively effective in terms of providing adequate disposal services. By contrast, this study has examined the environmental risk assessment associated with unregulated landfill sites in the Albert Luthuli municipality, in the Mpumalanga province. The determination of the environmental risk was achieved by the use of questionnaire surveys and landfill analysis forms in selected study areas. The findings have highlighted a very high environmental risk, nearly four times and above, the threshold limits set by the Department of Environmental Affairs and Tourism (DEAT, 2005:15) for all of the landfill sites examined. Several exposure pathways stemming from associated environmental impacts have also been identified for the study. The higher environmental risk determined for the problem sites is ascribed to numerous factors, including their ill-planned location, the sensitivity and vulnerability of the natural environment and adjacent rural settlements, the lack of appropriate waste pre-treatment processes prior to disposal, and most significantly, the lack of regulatory and control measures to contain the myriad of environmental problems generated. In conclusion, it is recommended that several measures (including closure) should be taken in order to reduce and contain the magnitude of environmental risks involved.
Environmental Sciences
M.Sc.(Environmental Sciences)

The mining industry produces vast quantities of overburden and mill tailings. In many instances the disposal of these wastes on the Earth's surface have caused local, and occasionally even regional, water resources to become contaminated. Contamination typically arises from the oxidation of metal sulfide minerals contained within these wastes. Upon oxidation these minerals release sulfate, their associated metal cations and acidity into solution. This study investigated the potential for groundwater contamination arising from a Pb/Zn tailings impoundment in the North West Province of South Africa (Pering Mine). The tailings is composed predominantly of dolomite, which imparts to the material an alkaline pH and a high acid buffering capacity. Acid-base accounting (ABA) established that the capacity of the tailings to buffer acidity surpasses any acid producing potential that could arise from pyrite (FeS2), galena (PbS) and sphalerite (ZnS) oxidation. These minerals account for about 3 to 6% of the tailings by mass. Total elemental analysis (XRF) showed that the material has high total concentrations of Fe (19083 mg kg-I), Zn (5481 mg kg-I), Pb (398 mg kg-I), S (15400 mg kg-I), Al (9152 mg kg-I) and Mn (29102 mg kg-I). Only a very small fraction of this, however, was soluble under saturated conditions. An estimation of potentially available concentrations, using the DTPA extraction method, indicated that high concentrations of Zn (1056 mg kg-I), and moderate concentrations of Pb (27.3 mg kg-I) and Cu (6.01 mg kg-I) could potentially be available to cause contamination. A number of leaching experiments were undertaken to accurately quantify the release of elements from the tailings material. These experiments were aimed at determining the potential for groundwater contamination and also provided a means whereby the long-term release of contaminants could be modelled using the convection-dispersion equation for solute transport. Four leaching treatments were investigated. Two consisted of using distilled water under intermittent and continuous flow, while a third used intermittent flow of deoxygenated distilled water to assess leaching under conditions of reduced oxygen. The.mobilisation of potential contaminants under a worst case scenario was assessed by means of leaching with an acetic acid solution at pH 2.88 (after the US Environmental Protection Agency's toxicity characteristic leaching procedure). The acid buffering potential of the tailings was considerable. Even after 8 months of weekly leaching with 1 pore volume of acetic acid solution the pH of the effluent was maintained above pH 5.90. The protracted acidity caused very high concentrations of Pb, Zn, Mu, Ca, Mg, Hg and S to be released into solution. Leaching the tailings with distilled water also caused the effluent to have noticeable traces of contamination, most importantly from S, Mg, Mu and Zn. In many instances concentrations significantly exceeded guideline values for South African drinking water. Modelling solute transport with the convectiondispersion equation predicted that sol- and Mu contamination could persist for a very long period of time. (±700 years under continuous saturated leaching), while Mg and Zn concentrations would most likely exceed recommended limits for a much shorter period of time (±300 years under the same conditions). In light of the various column leaching experiments it was concluded that seepage from the Pering tailings impoundment could cause groundwater contamination. A drill-rig and coring system were used to collect both tailings and pore-water samples from eight boreholes spread out across the tailings impoundment. These investigations showed that most of the impoundment was aerobic (Eh ranged from +323 to +454 mY) and alkaline (pH 8.0 to 9.5). This chemical environment favours sulfide oxidation and as a consequence high concentrations of S have been released into the pore-water of the impoundment (S concentrations ranged from 211 to 1221 mg r l ). The acidity released as a by-product of sulfide oxidation was being buffered by dolomite dissolution, which in turn was releasing high concentrations of Mg (175 to 917 mg r l ) and Ca (62.6 to 247 mg r l ) into solution. Metal concentrations in the pore-water were low as a result of the strong metal sorbing capacity of the tailings and possible secondary precipitation. The only metal which significantly exceeded recommended limits throughout the impoundment was Hg (concentrations were between 100 and 6000 times the recommended limit of 0.001 mg r l ). Under the current geochemical conditions it is expected that Hg, S and Mg will likely pose the greatest threat to groundwater. The main concerns associated with mine tailings are that of mine drainage and dust blow off..In order to eradicate the latter problem, the tailings impoundment at Pering Mine was covered with a layer of rocks. Modelling the water balance of the impoundment using the computer model HYDRUS-2D showed that the rock cladding has potentially increased the volume of drainage water seeping from the impoundment. In light of the leaching experiments and field work, which proved that water passing through the tailings became enriched with various potentially toxic elements, it is expected that the problem of groundwater contamination around Pering Mine has been further exacerbated by the rock cladding. It was therefore concluded that there would be a strong likelihood of groundwater contamination in the vicinity of the mine.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

The decision to bury high level nuclear wastes in deep geological formations led to the study of the Hanford Nuclear Reservation as one of three possible sites for the first nuclear waste repository in the United States. To adequately evaluate the environmental impact of siting nuclear waste repositories in basalt aquicludes, it is essential to know the effects on parameter identification algorithms of thermal gradients that exist in these basaltic aquicludes. Temperatures of approximately 60° C and pressures of approximately 150 atms can be expected at potential repository sites located at depths of approximately 1000m. The phenomenon of over-recovery has been observed in some pumping tests conducted at the Hanford Nuclear Reservation. This over-recovery phenomenon may possibly be due to variations in the fluid density caused by thermal gradients. To asses the potential effects of these thermal gradients on indirect parameter identification algorithms, a systematic scaling of the governing field equations is required in order to obtain dimensionless equations based on the principle of similarity. The constitutive relationships for the specific weight of the fluid and for the porosity of the aquiclude are assumed to be exponentially dependent on the pressure gradient. The dynamic pressure is converted to the piezometric head and the flow equation for the piezometric head is then scaled in radial coordinates. Order-ofmagnitude estimates are made for all variables in unsteady flow for a typical well test in a basaltic aquiclude. Retaining all nonlinear terms, the parametric dependency of the flow equation on the classical dimensionless thermal and hydraulic parameters is demonstrated. These classical parameters include the Batchelor, Fourier, Froude , Grashof, and Reynolds Numbers associated with thermal flows. The flow equation is linearized from order-of-magnitude estimates based on these classical parameters for application in the parameter identification algorithm. Two numerical solutions are presented which predict hydraulic head given a continuous set of flow parameters. The first solution uses a totally numerical finite difference scheme while the second combines an analytical solution with a numerical solution. A radial coordinate system is utilized for describing an anisotropic confined aquifer. The classical inverse parameter identification problem is solved using an indirect method. This method is based on the minimization of a objective function or error criterion consisting of three parts: 1) least-squares error of head residuals; 2) prior information of flow parameters; and 3) regularization. An adjoint equation is incorporated into the method to eliminate the need to differentiate the heads with respect to the parameters being identified, increasing the stability of the algorithm. Verification of the parameter identification algorithm utilizes both "synthetic", computed generated input data and field data from a well test for a confined aquifer within the Columbia Plateau near Stanfield, Oregon. The method used is found to give parameter estimates which are both stable and unique.
Graduation date: 1992

This case study was done in KwaZulu–Natal province in South Africa within two municipalities Ethekwini and Umsunduzi Municipality. Three communities participated in this study. The research is motivated by the lack of cooperation between some municipalities and Community Based Organisations (CBOs) in implementing the National Waste Management Strategy (NWMS) at a local level. The primary goal is to explore the availability and development of learning support materials (LSMs) that relates to waste management in collaboration with CBOs and local councillors. The secondary goal is to explore the use of learning support material to promote participation in the implementation of the NWMS. Coresearchers were from the Community Based Organisations as well as local councillors who are located within the communities of these CBOs. Pseudonyms for co-researchers from CBOs and Councillors and the name of their townships have been used to protect co-researchers. A literature review has been conducted to explore research that has been done on the development, usage, accessibility and distribution of the LSMs. Data collection methods included semi-structured interviews; field visits to communities, tape recording of discussions and the keeping of a field journal. Some of the key findings included that LSMs is used by both CBOs and Councillors to try to reduce local environmental problems. It also identified that there are no formal mechanisms between CBOs and Municipalities in dealing with waste management programmes within the identified communities. The other important finding was that the participation of CBOs in the development of LSMs normally excludes the user groups as a result language used is not always understood. Illustrations used in some cases may be misinterpreted if the reader is not English literate as most of material in circulation is written in English. Some recommendations for further research have been made in relation to the findings made in the study. These included recommendations on the development, usage of LSMs, participation of stakeholders in resource development within the context of CBOs and local municipalities.

Submitted in fulfillment of the requirements of the degree of Master of Health Sciences in Environmental Health, Durban University of Technology, Durban, South Africa, 2016.
In South Africa, under-five childhood morbidity and mortality rates have increased due to diarrhoea with acute diarrhoea posing a major public health threat especially, in informal settlements. Therefore this study sought to, a) investigate community knowledge, attitudes, behaviour and practices (KABP) regarding domestic waste and childhood diarrhoeal management, b) to enumerate and identify diarrhoeagenic E.coli species from soil samples extracted from open waste dump sites and c) to investigate any association(s) with diarrhoeagenic E.coli and potential risk of contracting diarrhoea. This two-phased cross-sectional study in six informal settlements in the greater Durban area constituted, respectively, of the administering of questionnaires to 360 primary caregivers and; sampling the prevalence of diarrhoeagenic E.coli (DEC) in waste dumps using quantitative polymerase chain reaction methodologies. Relationships between socio-demographic and educational status to determine potential household risk factors towards under-five diarrhoea prevalence were assessed. The KABP results identified domestic waste and greywater disposal, mother and child method of sanitation, personal and domestic hygiene practices and mechanical vectors as significant contributory risk factors. Of concern is that more than 80% of under-five children played in or near faecally-contaminated waste dump sites. The recovery of four DEC pathotypes including enterohaemorrhagic E.coli, enteropathogenic E.coli, enterotoxigenic E.coli and enteroaggregative E.coli suggest that its persistence in waste-dump soil has the ability to cause under-five diarrhoea in both sporadic and endemic settings. This commonly transmitted hand-to-mouth illness will necessitate and place huge demands on the primary catalysts of change i.e. local governmental role players and caregivers. These change agents have to ensure highly consistent levels of domestic and personal hygiene and implement feasible reduction strategies to waste-dump exposure of diarrhoeal-causing pathogens, particularly among under-five children living in Durban’s informal settlements.
M

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)