Capillary membrane-immobilised polyphenol oxidase and the bioremediation of industrial phenolic effluent
- Authors: Edwards, Wade
- Date: 1999
- Subjects: Membranes (Technology) , Effluent quality , Pollutants , Phenols , Water -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4095 , http://hdl.handle.net/10962/d1008458
- Description: Waste-generating industrialisation is intrinsically associated with population and economic proliferation. This places considerable emphasis on South Africa's water shortage due to the integral relationship between population growth rate and infrastructure development. Of the various types of industry-generated effluents, those containing organic pollutants such as phenols are generally difficult to remediate. Much work has been reported in the literature on the use of enzymes for the removal of phenols from these waste-streams but little application of this bioremediation approach has reached practical fruition. This study focuses on integrating and synergistically combining the advantages of enzyme-mediated dephenolisation of synthetic and industrial effluent with that of membrane teclmology. The ability of the enzyme polyphenol oxidase to convert phenol and a number of its derivatives to chemically reactive o-quinones has been reported extensively in the literature. These o-quinones can then physically be removed from solution using various precipitation or adsorption techniques. The enzyme is, however, plagued by a product-induced phenomenon known as suicide inactivation, which renders it inactive and thus limits its application as a bioremediation tool. Integrating membrane technology with the enzyme's catalytic ability by immobilising polyphenol oxidase onto polysulphone and poly(ether sulphone) capillary membranes enabled the physical removal of these inhibitory products from the micro-environment of the immobilised enzyme which therefore increased the phenol conversion capability of the immobilised biocatalyst. Under non-immobilised conditions it was found that when exposed to a mixture of various phenols the substrate preference of the enzyme is a function of the R-group. Under immobilised conditions, however, the substrate preference of the enzyme becomes a function of certain transport constraints imposed by the capillary membrane itself. Furthermore, by integrating a quinone-removal process in the enzyme-immobilised bioreactor configuration, a 21-fold increase in the amount of substrate converted per Unit enzyme was observed when compared to the conversion capacity of the inunobilised enzyme without the product removal step. Comparisons were also made using different membrane bioreactor configurations (orientating the capillaries transverse as opposed to parallel to the module axis) and different immobilisation matrices (poly(ether sulphone) and polysulphone capillary membranes). Conversion efficiencies as high as 77% were maintained for several hours using the combination of transverse-flow modules and novel polysulphone capillary membranes. It was therefore concluded that immobilisation of polyphenol oxidase on capillary membranes does indeed show considerable potential for future development.
- Full Text:
- Date Issued: 1999
Case studies of second language learners who excel at writing in English
- Authors: Ntete, Susan
- Date: 1999
- Subjects: Second language acquisition English language -- Study and teaching -- Foreign speakers Language and languages -- Study and teaching English language -- Writing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1429 , http://hdl.handle.net/10962/d1003310
- Description: This study, which was carried out in Mdantsane township in the Eastern Cape, attempts to explain why some learners from the former Department of Education and Training, and whose mother-tongue is Xhosa, are more proficient English Second Language (ESL) writers than others. As one who grew up as an ESL learner, and has taught as an ESL teacher in this area, my interest in this field of study has been triggered by the concern of one who has experienced educational disadvantage. My understanding of what it means to be an ESL writer, given the status that English enjoys in South Africa presently, has been the motivating force behind this study. The study focuses on competent ESL writers. It is hoped that other researchers, teacher educators and teachers will learn something from the practices and strategies used by the learners in this study. In its investigation this study employs case studies. For purposes of triangulation, multiple sources of data collection have been used. The major areas of focus are on the learners and their ESL writing practices. Collection of data includes formal interviews with both ESL learners and their teachers, informal interviews with the learners' Xhosa teachers, observation as well as text analysis. The findings of the study suggest, among other things, that more often than not, it is learners who are motivated extroverts, ambitious go-getters and uninhibited survivors who become excellent ESL writers. Like any study, this has certain limitations. As a result the interpretation of data has been expressed in tentative terms. This does not mean that there is nothing to be gained from a study of this nature. Instead, the aim is to challenge more researchers to take up this issue, so that generalis ability across case studies can be achieved.
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- Date Issued: 1999
Catalytic reactions of platinum group metal phthalocyanines
- Authors: Sekota, Mantoa Makoena C
- Date: 1999
- Subjects: Phthalocyanines Platinum group
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4396 , http://hdl.handle.net/10962/d1006151
- Description: The voltammetric behaviour of I-cysteine and other organic compounds such as hydrazine, hydroxylamine and methionine has been studied on GCE modified with phthalocyanine complexes of osmium, rhodium and ruthenium. For cysteine oxidation, the catalytic activity of the electrode was dependent the nature of the axial ligand. When cyanide and dimethylsulphoxide (DMSO) were used as axial ligands, giving (DMSO)(Cl)Rh(III)Pc, [(CN)₂Rh(III)Pc], (DMSO)₂0S(II)Pc and [(DMSO)₂Ru(II)Pc].2DMSO complexes, the peak current increased with repetitive scanning, indicating the increase in catalytic activity of the electrode after each scan. This behaviour was not observed when pyridine was used as axial ligand. The improvement of the catalytic activity of the GCE after the first scan has been attributed to the formation of the dimeric π-cation radical species at the electrode surface. Water soluble phthalocyanine complex ([(CN)₂Os(II)Pc]²⁻) and the tetramethyltetra-pyridinoporphyrazine complexes of Pd(II) and Pt(II), ([Pd(II)2,3Tmtppa(-2)]⁴⁺, [Pd(II)3,4Tmtppa(-2)]⁴⁺, [Pt(II)2,3Tmtppa(-2)]⁴⁺ and [Pt(II)3,4Tmtppa(-2)⁴⁺) have been prepared. [(CN)₂Os(II)Pc]²⁻ is soluble in water at pH greater 4 without the formation of dimers. The [M(II)Tmtppa(-2)]⁴⁺ (M = Pd or Pt) show high solubility in water and are stable only in acidic pHs. The cyclic voltammetry of the MPc and [M(II)Tmtppa(-2)]⁴⁺ complexes prepared, is also reported. The interactions of amino acids I-histidine and I-cysteine with the [M(II)Tmtppa(-2)]⁴⁺ complexes of Pd(II) and Pt(ll) were studied. All the [M(Il)Tmtppa(-2)]⁴⁺ are readily reduced to the monoanion species [M(Il)Tmtppa(-3)]³⁻ in the presence of histidine and cysteine. The rate constants for the interaction of [M(Il)Tmtppa(-2)]⁴⁺ complexes ofPt(II) and Pd(II), with histidine and cysteine range from approximately 2 x 10⁻³ to 0.26 dm³ mol⁻¹ s⁻¹. Kinetics of the interaction of [Co(Il)TSPc]⁴⁻ with amino acids, histidine and cysteine in pH 7.2 buffer were studied. The rate constants were found to be first order in both [Co(II)TSPc]⁴⁻ and the amino acid. The formation of [Co(III)TSPc]³⁻ in the presence of histidine occurred with the rate constant of 0.16 dm³ mol⁻¹ s⁻¹, whereas the formation of the [Co(I)TSPc]⁵⁻ species in the presence of cysteine gave the rate constant of 2.2 dm³ mo⁻¹ s¹. The relative quantum yield (QΔ) for singlet oxygen production by [(CN)₂Os(Il)Pc]²⁻, and [(CN)⁴Ru(II)Pc]²⁻ in DMF using diphenylisobenzofuran (DPBF) and a chemical quencher were determined. The quantum yield values were obtained as 0.39 ± 0.05 , and 0.76 ± 0.02 for [(CN₂Os(II)Pc]²⁻ and [(CN)₂Ru(II)Pc]²⁻ respectively. The differences in quantum yield values have been explained in terms of donor abilities of both the central metal and the axial ligands.
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- Date Issued: 1999
Claywork within the holographic paradigm: a transpersonal perspective on art therapy
- Authors: Diers, Belinda Gail
- Date: 1999
- Subjects: Art therapy , Transpersonal psychology , Art and holography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2962 , http://hdl.handle.net/10962/d1002471 , Art therapy , Transpersonal psychology , Art and holography
- Description: This thesis is grounded in the theoretical discourses of art therapy and transpersonal psychology. The focus is on a single session of claywork, where a sculpture was made and discussed, leading to an understanding of some of the sculptor's central psychological issues. The overall aim of the research was to examine different hermeneutic perspectives on art therapy with clay sculpture in terms of how well they open up and do justice to the experience of the sculptor and the nature of the overall process. Within this there are two particular goals: Firstly, to examine the extent to which the holographic paradigm in comparison to other perspectives, allows a deeper access to, and deeper understanding of, transpersonal themes and processes; and secondly, to examine the extent to which processes within claywork can be understood as ritual activities. The research was a phenomenological-hermeneutic case study. The session was reduced to a narrative synopsis, and then a hermeneutically grounded thematic analysis was carried out using the theory of Transpersonal Feminism (Knight, 1997) and Schema-Focused Cognitive Therapy (young, 1990, 1994). The principal conclusions reached were that the holographic paradigm does add to our understanding of the experiences (personal and transpersonal) of the claywork, often beyond the scope of other art therapy perspectives. The image of the shaman is used as a metaphor for understanding the process of healing described within the holographic paradigm. Within the healing process, ritual plays an important role in the meaningful therapeutic activity of art therapy. The claywork expresses that the transpersonal struggle with archetypal forces within the collective unconscious is reflected on a personal level through individual conflicts and dilemmas within the personal unconscious. Indeed, these difficulties are viewed on both levels as 'stepping stones' on the path of spiritual development described by Engler (1984) and Welwood (1986).
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- Date Issued: 1999
Cobalt (II) porphyrazine catalysed reduction of nitrite
- Authors: Thamae, Mamothibe , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293162 , vital:57061 , xlink:href="https://doi.org/10.1016/S0022-0728(99)00224-7"
- Description: Studies on the catalytic reduction of nitrite on carbon electrodes modified with Co(II) tetra-2,3-pyridinoporphyrazine (CoTppa, 1), N,N′,N′′,N′′′-tetramethyltetra-2,3-pyridinoporphyrazine ([CoTm-2,3-tppa]4+, 2) and Co(II) N,N′,N′′,N′′′-tetramethyltetra-3,4-pyridinoporphyrazine ([CoTm-3,4-tppa]4+, 3) are reported. There is a close correspondence between the proximity of the methyl groups to the porphyrazine ring and the catalytic activity of the porphyrazine complexes. Bulk electrolysis gave ammonia and hydroxylamine as some of the products. The catalytic activity of the cationic complex, 3, towards the detection of low concentrations of nitrite (less than 10−9 M) in water containing sodium sulfate, was compared with the activities of the anionic cobalt(II) tetrasulfophthalocyanine ([CoTSPc]4−, 4) and the mixed [CoIITm-3,4-tppa]4+·[CoTSPc]4− (5) complexes. Complex 5 showed the best catalytic activity of the three in that large currents were obtained for very low concentrations of nitrite.
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- Date Issued: 1999
Community based natural resource management systems : an evaluation of the campfire programme in Zimbabwe : with special reference to Omay, and Makande Communal Lands in Nyaminyami District
- Authors: Sibanda, Backson M C, 1950-
- Date: 1999
- Subjects: Natural resources -- Zimbabwe -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4866 , http://hdl.handle.net/10962/d1007432
- Description: Communal Areas Management for Indigenous Resources (CAMPFIRE) is an innovative community based natural resource management strategy which transfers management and conservation responsibility from the state to the local communities. This thesis critically examines CAMPFIRE's potential for introducing sustainable natural resource management through the detailed examination of CAMPFIRE's implementation in Nyaminyami District, which is located in the Zambezi Valley of Zimbabwe. Comparisons with other districts are made as appropriate. The theoretical framework of this research is based on an examination of common property theories, theories of bundles of rights, globalisation and the notion of global commons. It is also based on critically examining Zimbabwean, African and international literature dealing with the management of natural resources used in common. There are five specific contributions which the thesis makes. Firstly, common property management is redefined and the difference between resources used in common but which are not common property and common property resources is clarified. Secondly, the study shows that CAMPFIRE is not sustainable whilst it remains dependent on wildlife alone and on a single species - the elephant. Thirdly, the thesis has attempted to extricate the CAMPFIRE concept from the wildlife debate in which it has become entangled and, fourthly, it examines the issues of globalisation and the global commons to show how decisions made at the international level impact on resource utilisation and management at the local level. Finally, the study examines what residual Tonga indigenous knowledge still exists and which aspects can be incorporated into present management systems. Overall, the results of the research suggest that while CAMPFIRE is an innovative strategy for sustainable natural resource management it, has not achieved its major objective of becoming a grassroots rural development strategy. It has become a top down elitist programme which is NGO and donor driven and government constrained. Legislation and policy need formally to address this problem. Finally, the thesis recognises the potential of the CAMPFIRE concept, especially if the weaknesses ofthe programme are addressed.
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- Date Issued: 1999
Conservation biology and management of the Twee River redfin, Barbus erubescens (Pisces : Cyprinide)
- Authors: Marriott, Michael Stephen
- Date: 1999
- Subjects: Barbus , Cyprinidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5248 , http://hdl.handle.net/10962/d1005091 , Barbus , Cyprinidae
- Description: Agricultural practices and increasing levels of pollution, water abstraction and numbers of predatory exotic fishes gave rise to mounting concern for the survival of the already endangered Twee River redfin, Barbus erubescens. Numbers were believed to be dwindling and an urgent re-assessment of the species' conservation status and major threats was called for. Distribution and estimated numbers of B. erubescens were detennined from a census conducted in the Twee River catclunent, and baseline knowledge of age and growth, reproduction, diet and habitat preferences was gained from biological work on collected specimens. Such understanding was necessary to formullate management ideas. Although an estimated 40% reduction in area of occupancy has occurred in the middle reaches of the Twee River system, the known distribution of B. erubescens was extended into the upper Suurvlei River. Despite fragmentation, surviving redfin populations remained healthy and total population size was estimated at 8400 individuals, 4100 of which were considered mature. Adults preferred pools with water exceeding 1 m in depth and tended to be associated with sandy or boulder substrates. Due to low numbers no such study was conducted on juveniles, although observations indicated a preference for the upper 50 cm of the water column, in or around marginal vegetation. Barbus erubescens spawn in summer and follow an asynchronous, iteroparous pattern. Males and females reach a maximum age of six years, maturing after two years at calculated SL of 45 mm in males and 42 mm in females. The diet was dominated by simulid and ephemeropteran larvae. Although the combined pressures of pesticide and fertiliser use, predation and competition from exotic species have undoubtedly had a negative impact on B. erubescens, the species has maintained viable populations. With continued expansion of these threats the focus of conservation attention may change but, at present, it is most likely agricultural water use, amounting to 7.43 x 10⁶ m³y⁻¹, 15% of the entire catchment production, which poses the greatest immediate threat to the survival of the species. Based on a deteriorating habitat and restricted area of occupancy, B. erubescens was rated Critically Endangered, and it is recommended that a conservation management plan be implemented in the Twee River catchment. The focus of such action should be on genetic preservation, with immediate projects including gamete cryopreservation and captive breeding and rearing programmes. Catchment management, including education and rehabilitation programmes, must be the long-term aim of conservation, to ensure the survival of B. erubescens.
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- Date Issued: 1999
Constitution of Food and Allied Workers Union As amended at the Bi-Annual National Conference
- Authors: Food and Allied Workers Union (FAWU)
- Date: 1999
- Subjects: Food and Allied Workers Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110099 , vital:33223
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- Date Issued: 1999
Contents : 3 projects
- Authors: Mtongana, Lindile
- Date: 1999
- Subjects: Teachers -- In-service training School management and organization -- Parent participation Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1462 , http://hdl.handle.net/10962/d1003343
- Description: This project comprises a case study that I conducted at New Horizon High School in Butterworth, a school with a good reputation for its excellent academic standard. It is about Staff Development, which I have identified as the most vital component of effective teaching. Although there is a need to ensure that there is an adequate supply of teachers in schools, the greatest challenge lies in the development of the quality of those who are already in service. This enormous challenge seems to have been forgotten by many school leaders. I hope this study will be beneficial to school principals and teachers who want to be successful in their teaching careers in the 21st century.
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- Date Issued: 1999
Cumulative mild head injury in rugby: cognitive test profiles of professional rugby and cricket players
- Authors: Ancer, Ruth Lauren
- Date: 1999
- Subjects: Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2925 , http://hdl.handle.net/10962/d1002434 , Head -- Wounds and injuries , Rugby football injuries , Cricket injuries , Cognitive therapy , Neuropsychological tests
- Description: This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.
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- Date Issued: 1999
D'jinke Mousso
- Authors: Batoma Sissoko (lead singer) , Batoma Sissoko
- Date: 1999
- Subjects: Popular music , Popular music--Africa, West , Africa Mali Bamako f-ml
- Language: Malinka
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/131154 , vital:36529 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC50-01
- Description: Mandingo popular song with lead female vocal, accompanied by chorus, n'goni, balafon, Malian percussion, and other traditional Malian instruments, combined with Western guitar and drums
- Full Text: false
- Date Issued: 1999
Dankorobo
- Authors: Koniba Traore (author, composer, interpreter, performer) , Straun Douglas
- Date: 1999
- Subjects: Choral music , Men's chorus , Mixed chorus , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/125478 , vital:35787 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDCO1-02
- Description: Malian traditional music
- Full Text: false
- Date Issued: 1999
Declaration on HIV/AIDS
- Authors: COSATU, SAMWU
- Date: 1999
- Subjects: COSATU, SAMWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/162072 , vital:40754
- Description: This Special Congress of COSATU notes the relentless advance of HIV and AIDS since the 1997 Congress. 3,5 million people in South are infected with the Human Immuno-deficiency Virus (HIV). Life expectant South Africa will reduce to 40-45 over the next ten years and health care costs will be beyond the cape of survivors to pay for. It is now clear that publicity and condom distribution, though important, are enough. This requires a new approach and strategy, based on a partnership between government and society in which the organised working class should play a leading role.
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- Date Issued: 1999
Devaluation
- Authors: Batoma Sissoko (lead singer) , Batoma Sissoko
- Date: 1999
- Subjects: Popular music , Popular music--Africa, West , Africa Mali Bamako f-ml
- Language: Malinka
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/131205 , vital:36536 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC50-06
- Description: Mandingo popular song with lead female vocal, accompanied by chorus, n'goni, balafon, Malian percussion, and other traditional Malian instruments, combined with Western guitar and drums
- Full Text: false
- Date Issued: 1999
Development and characterisation of a membrane gradostat bioreactor for the bioremediation of aromatic pollutants using white rot fungi
- Authors: Leukes, W
- Date: 1999
- Subjects: Aromatic compounds Pollutants Fungi Bioremediation Industrial microbiology Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4032 , http://hdl.handle.net/10962/d1004092
- Description: Bioremediation of aromatic pollutants using the ligninolytic enzymes of the white rot fungi has been thoroughly researched and has been shown to have considerable potential for industrial application. However, little success in scale-up and industrialisation of this technology has been attained due to problems associated with the continuous production of the pollutant-degrading enzymes using conventional bioreactor systems. The low productivities reported result from the incompatibility of conventional submerged culture reactor techniques with the physiological requirements of these fungi which have evolved on a solid-air interface, viz. wood. The enzymes are also produced only during the stationary phase of growth and can therefore be regarded as secondary metabolites. This study reports the conceptualisation, characterisation and evaluation of a novel bioreactor system as a solution to the continuous production of idiophasic pollutant degrading enzymes by the white rot fungus Phanerochaete chlysosporium. The reactor concept evolved from observation of these fungi in their native state, i. e. the metabolism of lignocellulosic material and involves the immobilisation of the organism onto a capillary ultrafiltration membrane. Nutrient gradients established across the biofilm, an inherent characteristic of fixed bed perfusion reactors, are exploited to provide both nutrient rich and nutrient poor zones across the biofilm. This allows growth or primary metabolism in the nutrient rich zone, pushing older biomass into the nutrient poor zone where secondary metabolism is induced by nutrient starvation. In effect, this represents a transformation of the events of a batch culture from a temporal to a spatial domain, allowing continuous production of secondary metabolites over time. Direct contact of the outer part of the biofilm with an air stream simulated the solid-air interface of the native state of the fungus. In order to facilitate the practical application of the membrane gradostat reactor (MGR) concept, conventional capillary membranes and membrane bioreactor modules were first evaluated. These were found to be unsuitable for application of the MGR concept. However, critical analysis of the shortcomings of the conventional systems resulted in the formulation of a set of design criteria for the development of a suitable membrane and module. These design criteria were satisfied by the development of a novel capillary membrane for membrane bioreactors, as well as a transverse flow membrane module, which is a novel approach in membrane bioreactor configuration. For the physiological characterisation of the MGR concept, a single fibre bioreactor unit was designed, which allowed destructive sampling of the biofilm for analysis. Using this system, it was shown that distinct morphological zones could be observed radially across the mature biofilm obtained through MGR operation. That these morphotypes do represent the temporal events of a typical batch culture in a spatial domain was confirmed by following the morphological changes occurring during batch culture of the immobilised fungus where the onset of primary and secondary metabolic conditions were manipulated through control of the nutrient supply. The different morphotypes were correlated to distinct growth phases by comparison of the morphology to the secretion of known enzymatic markers for secondary metabolism, viz. succinate dehydrogenase and cytochrome C oxidoreductase. Detailed structure-function analysis of the biofilm using transmission electron microscopy and adapted enzyme cytochemical staining techniques showed that the biofilm appeared to operate as a co-ordinated unit, with primary and secondary metabolism apparently linked in one thallus through nutrient translocation. This study provided new insights into the physiology of P. chrysosp,o rium and a detailed descriptive model was formulated which correlates well to existing models of wood degradation by the white rot fungi (WRF). Evaluation of the process on a laboratory scale using a novel transverse flow membrane bioreactor showed that a volumetric productivity of 1916 U.L.⁻¹day⁻¹ for manganese peroxidase, one of the pollutant degrading enzymes, could be attained, corresponding to a final concentration of 2 361 U.L.⁻¹ This may be compared to the best reported system (Moreira el at. 1997), where a volumetric productivity of 202 U.L.⁻¹day⁻¹was achieved with a final concentration of 250 U.L.⁻¹ However, MGR productivity is yet to be subjected to rigorous optimisation studies. The process could be operated continuously for 60 days. However, peak productivity could not be maintained for long periods. This was found to be due to physical phenomena relating to the fluid dynamics of the system which caused fluid flow maldistribution, which would have to be resolved through engineering analysis. In evaluation of the MGR concept for aromatic pollutant removal, in this case ρ- cresol, from growth medium, good performance was also achieved. The VmaxKm calculated by linear regression for the MGR was 0.8 (R² = 0.93), which compared favourably to that reported by Lewandowski et al. (1990), who obtained a Vmax/Km of 0.34 for a packed bed reactor treating chlorophenol. It was concluded that the MGR showed suitable potential to warrant further development, and that the descriptive characterisation of the biofilm physiology provided a sufficient basis for process analysis once engineering aspects ofthe system could be resolved.
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- Date Issued: 1999
Development of a model of performance indicators required for the effective management of South African Universities and Technikons
- Authors: Hutton, Wendy
- Date: 1999
- Subjects: Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10826 , http://hdl.handle.net/10948/16 , Universities and colleges -- South Africa -- Management , Performance -- Management , Performance standards , Performance -- Measurement
- Description: Research has been conducted on performance indicators in higher education institutions in a number of countries. However, in South Africa limited research in this field on a national level is available to the management of South African higher education institutions. The change in funding of these institutions has led to performance measurement becoming essential in order to justify the use of public funds. In order to obtain more relevant information about performance indicators in the South African context, a literature study was conducted to develop a questionnaire to test the concurrence of the importance of performance indicators in South African universities and technikons. The findings of the survey shows a high level of concurrence for the performance indicators identified in the literature study.
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- Date Issued: 1999
Development of integrated biological processing for the biodesalination of sulphate- and metal-rich wastewaters
- Authors: Boshoff, Genevieve Ann
- Date: 1999
- Subjects: Sewage -- Purification -- Biological treatment Sulfates Mineral industries -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3899 , http://hdl.handle.net/10962/d1003958
- Description: The substantial pollution threat to the South African environment from acid mine drainage (AMD) effluents has been well documented. Due to the juvenile nature of acidity in these flows, any remediation strategies implemented will need to function effectively and at low cost for long periods of time. The widespread use of sulphate reducing biological systems for the treatment of such effluents, and in particular large volume flows, has been limited. The supply of inexpensive electron donor and carbon sources, as well as appropriate reactor designs capable of handling large volume flows, have been identified as among the principal factors limiting development of this technology. The broad aim of the research programme reported here was to undertake an evaluation of the feasibility of an algal-bacterial integrated ponding system for the treatment of AMD, and the waste stabilisation pond (WSP) as an appropriate reactor design for this application. The study attempted to demonstrate the feasibility of individual unit operations in a proposed process train using complex organic carbon serving as the electron donor source for the sulphate reducing bacteria (SRB). Studies were undertaken as laboratory and pilot-scale investigations. Tannery effluent was shown to be a functional carbon source for biological sulphate reduction, with effective removal of sulphate and organics being recorded. In turn, the use of biological sulphate reduction for the treatment of tannery effluent was demonstrated. Algal biomass was shown in laboratory studies to function as an effective carbon source for biological sulphate reduction. It is known that micro-algae produce large quantities of photosynthate which is released to the growth medium under conditions of physiological stress. The potential for the use of photosynthate production in high rate algal ponding systems and its manipulation and use as a sustainable carbon source for sulphate reduction was investigated. Growth of a mixed culture of Dunaliella under conditions of light, temperature and salinity stress demonstrated production of large quantities of organic carbon. However, growth was inhibited at high temperatures. An elevation of salinity levels led to a decrease in growth of Dunaliella, but to increased organic carbon production. Spirulina spp., on the other hand, grew well at higher temperatures but showed the highest organic carbon production, and release to the medium, under low light conditions. These results led to a proposed process for the integration of algal ponding into an integrated system for the treatment of AMD. The algal biomass may be fed into the anaerobic digester as a carbon source, or it may be passed into a High Rate Algal Pond (HRAP) where it is stressed to enhance the organic carbon content. This can then be fed into the anaerobic digester as a carbon source. The impact of high levels of sulphide in the water feeding to the algal growth compartment was investigated. Spirulina spp. isolated from a tannery waste stabilisation pond was shown to be a sulphidophilic strain of cyanobacterium, capable of being adapted to high concentrations of sulphide. Dunaliella salina on the other hand was less tolerant. These results demonstrated the practical use of algal biomass providing an oxygen-rich cap for odour control on the surface of the facultative pond as well for the secondary treatment of sulphide-rich overflow to the High Rate Algal Pond. The ability of micro-algae to elevate the pH of their surrounding environment was evaluated as a functional precipitant and neutralisation reagent for acidic metal containing wastewater. Spirulina spp. was shown to perform effectively. D. salina was less functional in this environment. Anacystis spp. was effective in elevating the pH of a defined medium as well as a zinc-rich effluent. These results indicated the practicality of a neutralising function for algal ponds in the treatment of AMD. Metal removal in the system was found to be a combined function of sulphide precipitation, removal by binding to micro-algal biomass and extracellular polymeric substances. The feasibility of waste stabilisation ponding technology use for the treatment of large volume AMD effluents was provisionally demonstrated. It was shown that complex carbon sources would be used as efficient electron donors for sulphate reduction. The integration of algal ponding into the system provides for the generation of a sustainable carbon source, odour control with the recycling of oxygen-rich water onto the top of the facultative pond, secondary treatment of the anaerobic digester overflow, and the neutralisation of the incoming acidic effluents and removal of heavy metals. Integration of the individual unit operations, the feasibility of which has been provisionally demonstrated in this study, into a continuous process train is being investigated in follow-upstudies.
- Full Text:
- Date Issued: 1999
Dianguina
- Authors: Rokia Traore (vocals, guitar, lyrics, composition) , Andra Kouyate, Baba Sissoko (n'goni) , Oumar Diallo, Abdoul W. Berthe (bass guitar) , Samba Diarra (balafon) , Dimba Camara, Souleymane Ann (percussion, gita) , Baba Sissoko (djembe) , Samir Naman
- Date: 1999
- Subjects: Popular music , Popular music--Africa, West , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130761 , vital:36476 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC46-07
- Description: Malian song accompanied by traditional Malian instruments, adddressing the responsiblity of bringing a child into the world
- Full Text: false
- Date Issued: 1999
Diarabi
- Authors: Mamou Sidibe (composer, author, lead singer) , Yves Wernert (bass, recording engineer)) , Boua Diakite (kamelen'ngoni) , Moussa Kanoute (karignan) , Ramata Diakite (chorus) , Moussa Kone (accoustic and electric guitar) , Adama Traore (calebasse) , MALI K7 S.A. Ali Furka Toure Associe, Bamako
- Date: 1999
- Subjects: Popular music--Africa, West , Folk music , Africa Mali Bamako f-ml
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129880 , vital:36342 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC34-06
- Description: Traditional Malian song in the Wasssoulou style overlaid with modern techno sound producing Mali-Techno music and giving the performer the nickname techno-Mamou
- Full Text: false
- Date Issued: 1999
Didadi
- Authors: Namakoro Fomba (author, composer, callebasse, Donso n'goni) , Koko Dembele (guitar) , Abdoul Wahab Berthe (bass guitar, karignan) , Assanatou Kouyate, Assetou Kone (chorus) , MALI K7 S.A. Ali Furka Toure Associe, Bamako
- Date: 1999
- Subjects: Popular music--Religious aspects , Popular music--Africa, West , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130384 , vital:36411 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC42-03
- Description: Traditional Malian music that reflects the spiritual rhythm of Komo worship of the Malinke, Bambara, Kagoro, Fulani, Manding, Fouladougou and Girgo and Bougouni peoples of Mali
- Full Text: false
- Date Issued: 1999