Thesis (M.Tech.: Biotechnology)-Dept. of Biotechnology, Durban Institute of Technology, 2005 xiv, 114 leaves : ill. 30 cm / The activated sludge process is the mostl used biological treatment process. Engineers and microbiologists are constantly seeking ways to improve process efficiency, which can be attributed to the increasing demand for fresh water supplies and proper environmental management. Since the inception of the activated sludge process, bulking and foaming have been major problems affecting its efficiency. Filamentous bacteria have been identified as the primary cause of bulking and foaming. Numerous attempts have been made to resolve this problem. Some of these attempts were effective as interim measures but failed as long term control strategies. The identification of filamentous bacteria and the study of their physiology have been hampered by the unreliability of conventional microbiological techniques. This is largely due to their morphological variations and inconsistent characteristics within different environments. To fully understand their role in promoting bulking and foaming, filamentous bacteria need to be characterized on a molecular level. The aim of this study was, therefore, to identify filamentous bacteria in pure culture with the purpose of validating these findings to the physiological traits of the pure cultures when they were isolated. Fourteen different filamentous cultures were used for this study. The cultures were identified using specific oligonucleotide probes via fluorescent in situ hybridisation and nucleotide sequencing. Prior to sequencing, an agarose gel and a denaturing gradient gel Electrophoresis profile were determined for each isolate. The various techniques were optimised specifically for the filamentous isolates. The isolates were identified as Gordonia amarae, Haliscomenobacter hydrossis, Acinetobacter sp./Type 1863, Type 021N, Thiothrix nivea, Sphaerotilus natans and Nocardioform organisms.

This thesis is a case study investigation of the sustainability of private sector participation in water supply and sanitation in developing countries, with a particular emphasis on South Africa. It is essentially an empirical contribution, which adds to the body of literature pertaining to the privatisation of water supply and sanitation services in developing countries. South Africa, like many developing countries, faces a significant challenge in providing a sustainable water supply and sanitation service to its citizens. It has a vast water supply and sanitation infrastructure backlog, because of the previous apartheid) government's minimal attention to the basic service needs of the African, Indian and Coloured people. This lack of basic services has had a negative effect on people's health and their basic living conditions. The traditional delivery vehicles for water supply and sanitation delivery in South Africa have been its municipalities. After the demise of the apartheid government, the democratic national government restructured these municipalities under various. processes. They merged neighbouring towns and villages, which incorporated former rural areas to achieve economies-of-scale. The intention was to ensure service delivery to the previously disadvantaged, through a mechanism of cross-subsidisation from the affluent to the indigent. However, these newly-demarcated non-metropolitan municipalities, still do not have the finances to extend the water supply and sanitation infrastructure network to rural areas within their jurisdiction. They also lack the good credit ratings to borrow funds from banks to finance new water supply and sanitation infrastructure. The rural population also has low abilities-to-pay for water supply and sanitation services. With total basic infrastructure backlogs estimated to exceed R270 billion in South Africa, the challenge to all tiers of government is considerable. Just rural water supply and sanitation over the next ten years requires R13.5 billion for the financing of new and rehabilitation of old, infrastructure. Faced with this dilemma, national government has attempted to resolve it by following the route taken by other developing nations, that is, by seeking the assistance of the private sector, National,provincial, or access to it. and some local governments argue that it is only the private sector that has the financial resources to fund this infrastructure backlog. To facilitate this change in service delivery vehicles. national government developed legislation to create an enabling environment for the entry of the private sector in the arena of water supply and sanitation provision. This transition has occurred with significant controversy and opposition. Many opponents to any form of privatisation base their argument on privatisation's fundamental drivers not being aligned with the goals of a development state. In the South African situation, these opponents include some organised labour trade unions, researchers, and labour-based research organisations. With firm pressure from this antiprivatisation coalition, private sector participation in water supply and sanitation services has been significantly staggered or impeded. Whilst this study provides evidence that this case of privatisation is not sustainable in the long-term, which is in agreement with this anti-privatisation coalition, the reasons underpinning the conclusion of this study, differ significantly from those of this coalition. The arguments that underpin differences in the opposition's views and this thesis are analysed throughout the rubric of this study. Three elemental constructs underpin the theoretical framework of this study. These constructs are compartmentalised into the nature of public goods and their natural monopoly status, the efficiencies of privatisation and its relation to ethics. and globalisation issues specifically dealing with the roles oftransnational companies. The study will show that the transfer of water supply and sanitation service delivery to the private sector in South Africa has not been sustainable due to various factors. These factors are investigated through the medium of empirical and case study analyses at a national and global comparative scale. Factors investigated include the reasons behind the privatisation, its transition period and procurement of public and other stakeholder buy-in to the change in service delivery, the role that the state has played in providing the enabling environment for privatisation, and the effectiveness of the opposition in delaying or impeding the pace of privatisation. The study also reveals that pilot projects have a special status and access to greater institutional support, which might facilitate its success. This extra attention might not be realisable in successive projects. Factors underpinning a successful privatisation include issues of efficiency, regulation and financial issues. These are also investigated within the rubric of the empirical and case study analyses. The impact of globalisation and the role of transnational companies with apparently "new technologies" and foreign direct investment, which pervade water supply and sanitation privatisation in developing countries, are also discussed. The case study examinations also provide evidence that in the South African situation, these apparent foreign technological innovations have yet to be confirmed. For South Africa and the other developing nations, the foreign direct investment has also been minimal in comparison to the profits that leave these host countries from the water supply and sanitation sector. The primary case study that underpins this research is the pilot project test case for the South African national government, the Dolphin Coast concession in its Kwazulu-Natal province . A comprehensive investigation of this concession provides evidence of the project's commercial failure. However, the concession remains in the hands of a private sector operator, due to the municipality controversially renegotiating the terms of the contract to facilitate the concession's continuity. This "municipal intervention" trend is noticeable in some international case studies. The English privatisation case is also investigated to provide a contrast between privatisation in a developed nation and a developing one. It also provides an insight into the facilitative environment of the English privatisation case, as compared to that of developing nations. The English privatisation, although not without controversy, was a decision taken by the government on efficiency grounds, whilst developing nations have taken the privatisation step based on reasons of infrastructure deficiency and a lack of finance. Essentially, the former is a push factor, whilst the latter has been a pull factor. This thesis includes a case study investigation conducted at the World Bank in New Delhi, India, which provides evidence of the opposition from state bureaucrats to privatisation in India. This serves as a contrast to the organised worker opposition in South Africa, and highlights some of the differing impediments that face privatisation attempts in each respective country. It shows that the reasons underpinning the opposition to privatisation in developing nations facing similar crises are, in fact, dissimilar. The study also investigates the success that can be achieved through the economies-of scale of a public sector utility in South Africa, shown by the Umgeni Water case study. This is essentially a public agency that has corporatised5 along business principles and employed economies-of-scale to become a successful example of public sector water supply and sanitation provision in a developing country. Cumulatively, this study provides evidence that, in South Africa, the transfer of water supply and sanitation services to the private sector is not sustainable without some degree of state intervention. This is especially evident in cases where there are no economies-of-scale to be exploited, and a lack of affluent people to ensure a critical degree of payment of tariffs or cross-subsidisation to the indigent. In effect, by transferring these services to private hands, this would serve only to postpone the eventual lack of sustainability that these services are currently experiencing in public sector hands. The evidence reveals that the privatisation of water supply and sanitation services in South Africa is not a commercially viable option in the long-term, under the normal mechanisms of supply and demand of the market. Concomitantly, the South African national government and its municipalities are faced with a new dilemma. The private sector can provide immediate sources of financing for urgent water supply and sanitation infrastructure development that cannot be similarly procured from limited state funds or other sources. Considering the urgency to provide water supply and sanitation infrastructure, because of the health-related effects that no access creates, privatisation, with strong regulation, may be a more amicable alternative to the current financial restrictions on municipalities, until a more comprehensive and sustainable solution is found. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

Despite its phasing out in numerous countries, such as Germany and the U.S.A., co-disposal of hazardous waste with municipal solid waste continues to be widely practised in South Africa. Co-disposal utilises properties and microbial activities in the refuse to attenuate the hazardous waste and thus obviate its environmental impact potential. All landfill operations require careful planning in not only site selection criteria but also the type and amount of various wastes accepted for disposal. It is clear, however, that the practice of co-disposal requires special precautions and management as the methods employed in the landfill operation determine to a large extent the environmental effects and, thus, the public acceptability of the operations. Although co-disposal is not suitable for all industrial wastes the results of recent research efforts, conducted mainly in the U.K., have indicated that, when properly managed, co-disposal can be regarded as a safe and efficient disposal option for many hazardous wastes. Environmental awareness in many European countries ensures that numerous hazardous compounds are either recycled or recovered. Unfortunately, in South Africa the lack of similar concern has resulted in increased concentrations of toxic compounds being co-disposed on a regular basis. Since fundamental studies of this technology, pertaining to South African conditions, have been lacking laboratory models/microcosms were built to address this paucity. Model. To effect the separation of species habitat domains of component species of growth rate-dependent interacting microbial associations responsible for terminal catabolic processes of the refuse fermentation, with retention of overlapping activity domains, and so facilitate examination of species in isolation without violating the integrity of each association, multi-stage models were constructed. The accidental overgassing of the culture with liquid petroleum gas (LPG) effected interesting fermentation balance changes which also emphasised the need for an Anaerobic Bioassay Test to assess the impacts of specific perturbants. Evidence of differential susceptibility of the component species to phenol was demonstrated in this study. Microcosm. A total of 42 refuse packed single-stage glass column bioreactors were commissioned and subjected to phenol and/or anaerobically digested sewage sludge codisposal. The effects of four different operational modes: leachate discard (single elution); leachate recycle; batch; and simulated rain on the co-disposals as well as refuse catabolism per se were examined. The results of these studies indicated that protracted periods of adaption to phenol (1000 and 2000 mg l -1) could have resulted from nutrient (elemental) limitation. Circumstantial evidence was also gained which indicated that the nitrate- and sulphate-reducing bacteria (SRB) were particularly sensitive to the added xenobiotic. Further, without the effective participation of the nitrate- and SRB the active and total fermentation of both the phenol and refuse components were depressed. It was also determined that the operating regime employed was a key factor in refuse degradation although with time, and especially following the phenol resupplementations, the operating conditions played a less significant role. In general, the single elution operated columns demonstrated increased phenol removal rates which were, unfortunately, coincident with low pH values and increased leachate residual phenol concentrations. Leachate recycle, on the other hand, unlike the batch operated columns, facilitated increased pH values and methane evolutions. The simulated rain columns were characterised by rapid washout of the added phenol as well as methanogenic precursors. The sewage sludge co-disposal experiments, likewise, demonstrated that, depending on the sludge:refuse ratio, the operating regime was extremely important in optimising the refuse degradation processes although, in general, leachate recycle appeared to be the most favoured method of operation. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1996.

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.

Bacteriological data from 1980 to 1991 were reviewed to determine whether coliform bacteria occurred seasonally and spatially within a midwestern city's distribution system. Coliform bacteria are used as microbiological indicator organisms to determine if a public water supply is safe for consumption. The public water_ distribution system examined had at least a twelve year history of the presence of coliform bacteria. Previous investigations have described the occurrence of the coliform bacteria as sporadic because there were no apparent patterns to their presence. An analysis of bacteriological data has not previously been performed to specifically detect seasonal and spatial occurrences of coliform bacteria.This study attempted to determine if seasonal or spatial patterns of coliform occurrences exist within the in the dominant coliform species. Data indicate that the highest percentage of coliform positive samples occurred in the summer, followed by fall, then winter, with spring having the lowest percentage of coliform positive samples. While Enterobacter cloacae was the dominant coliform species during the spring, summer and fall, Klebsiella oxytoca was the dominant coliform during the winter. Coliform occurrence throughout the distribution system was variable among the 43 sample sites. The percentage of positive samples from the various sites ranged from 0% to 10.5%. The five sites with the highest percentage of coliform positive samples were at the extremities of the distribution system. E. cloacae was dominant at 88% of the sites. K. oxytoca was dominant at 9% sites, which typically had a low percentage of coliform positive samples. / Department of Biology

Efforts by designers to produce solutions to environmental problems has become increasingly sophisticated. Inter-disciplinary teams of designers, engineers and scientists have proposed new and dynamic resolutions to environmental disturbances. There is a problem, however, in the ability of such proposals to be accepted and implemented.This study investigated the possibility that communication of these plans has been responsible for the lack of acceptance. Citizens and governmental officials must adequately comprehend the proposed solutions before they can gain confidence and judge them worthy of implementation. This study searched for aspects of communication necessary to successfully promote pre-planning and reclamation for correcting and preventing environmental problems in sanitary landfills.A random survey of Delaware County, Indiana established base means for concerns (aesthetic, pollution, property value, safety, etc.) in a typical population cross-section. The net effectiveness of the landfill presentation (communication) effort was to be inferred through noted changes in the level of concern between the typical population and the test group who witnessed the educational presentation.The comparative test could not proceed. The focus of this study was then directed towards more intimate analysis of the attitudinal data provided in the cross-sectional survey. A number of obvious and obvious characteristics were revealed.In the end, this study has provided significant insight into the "posture" of the most important link in convincing that planning and design solutions can mitigate environmental problems. That link is at the receiving end of such communication efforts... the "public" with its constructs of fears and biases. / Department of Landscape Architecture

Lightweight engineering plastics have been increasingly used in automotive applications(3), this tends toward more fuel efficient vehicles(1). Glass reinforced plastics commonly include thermosetting polymers. These cannot be re-moulded, unlike thermoplastics, thus thermoset scrap is currently disposed of in landfill. This is increasingly targeted by legislation(14) and is becoming more expensive. This thesis describes work to maximise resource recovery from scrap thermoset composites. A review of relevant literature identified thermal processes for treating scrap thermoset composites. Combustion is particularly suitable for the mixed and contaminated materials arising from end of life vehicles. The literature showed that heating glass fibres reduced their properties, which is a concern for any thermal recycling process. The methodology of this work is to recover energy from the composite polymer and reuse the incombustible residues. Two experimental processes are reported: Fluidised Bed Co-combustion of Thermoset Composites with Coal. The common composite filler of calcium carbonate captures the sulphur emissions from the coal combustion. Results show that scrap composites can successfully be burned in a commercial scale fluidised bed. Retention of the sulphur from the coal by the composite filler was up to 75 % of the input. Although a technical success, economic analysis shows this disposal to be unviable compared with similar desulphurisation via crushed limestone. Fluidised Bed Thermal Processing Rig for Recovering Glass Fibres. The incombustible constituents of a crushed Sheet Moulding Compound were released from processing above 400 ° C in the fluidised bed test rig. The reinforcing glass fibres were elutriated as monofilaments, suitable for use in a veil product, and recovered from the flue gases. Scanning Electron Microscopy showed that the fibres were intact. The tensile strength of fibres from 450°C processing was reduced by approximately 50% and by 90% from 650°C(73). Strength was also found to reduce with increasing time at a temperature(76) . Flue gas analysis showed that carbon monoxide and hydrocarbons were present. This indicated that full combustion did not take place and the associated heat energy lost. Measured nitrogen oxides and sulphur dioxide concentrations were low. After initial testing, the test rig was refined by the incorporation of a Rotating Screen Collector to separate the fillers and fibres. The fibre contamination was reduced by 50% via this novel equipment. Fibre recovery rates of up to 57% were achieved. Resin Decomposition Model. Results indicate that the resin endothermic energy of decomposition maintained the temperature of the Sheet Moulding Compound significantly below the bed temperature.

Cementitious building components, although widely used in low-income countries, are too expensive for many applications related to low-income housing. This thesis explores three options for reducing component cost: 1. Use of local fine aggregates, often with clay contamination, instead of low-fines sands transported from a distance. 2. Improved designs, to achieve better material economy. 3. Change of production environment, from on-site to component prefabrication followed by transport to site. Water storage tanks for rainwater harvesting were used as the example for component design, and as a case-study for considering the effect of changing the production environment. The work showed that: In some cases, use of local aggregates will give a cost saving of around 10%. Improved design can give significant reduction in materials usage, of up to 40%. Off-site prefabrication of components, followed by on-site assembly to produce the desired product, does not seem preferable to the prevelant practice of entirely on-site production from raw materials. However, factory-based manufacture of complete products, followed by transport to site, has a number of attractions over entirely on-site production. Out of the three options examined, improved component design offers the greatest benefits for the case study considered.

The rise velocity of injected air phase from the injection point toward the vadose zone is a critical factor in in-situ air sparging operations. It has been reported in the literature that air injected into saturated gravel rises as discrete air bubbles in bubbly flow of air phase. The objective of this study is to develop a quantitative technique to estimate the rise velocity of an air bubble in coarse porous media. The model is based on the macroscopic balance equation for forces acting on a bubble rising in a porous medium. The governing equation incorporates inertial force, added mass force, buoyant force, surface tension and drag force that results from the momentum transfer between the phases. The momentum transfer terms take into account the viscous as well as the kinetic energy losses at high velocities. Analytical solutions are obtained for steady, quasi-steady, and accelerated bubble rise velocities. Results show that air bubbles moving up through a porous medium equilibrate after a short travel time and very iv short distances of rise. It is determined that the terminal rise velocity of a single air bubble in an otherwise water saturated porous medium cannot exceed 18.5 cm/sec. The theoretical model results compared favorably with the experimental data reported in the literature. A dimensional analysis conducted to study the effect of individual forces indicates that the buoyant force is largely balanced by the drag force for bubbles with an equivalent radius of 0.2-0.5 cm. With increasing bubble radius, the dimensionless number representing the effect of the surface tension force decreases rapidly. Since the total inertial force is quite small, the accelerated bubble rise velocity can be approximated by the terminal velocity.

Current activated sludge models are deterministic in character and are constructed by basing on the fundamental biokinetics. However, calibrating these models are extremely time consuming and laborious. An easy-to-calibrate and user friendly computer model, one of the artificial intelligence techniques, Artificial Neural Networks (ANNs) were used in this study. These models can be used not only directly as a substitute for deterministic models but also can be plugged into the system as error predictors. Three systems were modeled by using ANN models. Initially, a hypothetical wastewater treatment plant constructed in Simulation of Single-Sludge Processes for Carbon Oxidation, Nitrification &amp / Denitrification (SSSP) program, which is an implementation of Activated Sludge Model No 1 (ASM1), was used as the source of input and output data. The other systems were actual treatment plants, Ankara Central Wastewater Treatment Plant, ACWTP and iskenderun Wastewater Treatment Plant (IskWTP). A sensitivity analysis was applied for the hypothetical plant for both of the model simulation results obtained by the SSSP program and the developed ANN model. Sensitivity tests carried out by comparing the responses of the two models indicated parallel sensitivities. In hypothetical WWTP modeling, the highest correlation coefficient obtained with ANN model versus SSSP was about 0.980. By using actual data from IskWTP the best fit obtained by the ANN model yielded R value of 0.795 can be considered very high with such a noisy data. Similarly, ACWTP the R value obtained was 0.688, where accuracy of fit is debatable.