Thesis (PhD (Curriculum Studies))-- University of Stellenbosch, 2009 / ENGLISH ABSTRACT: The aim of this study was to develop a curriculum framework for engineering introduction programmes offered at a higher education institution, using a case study design. The South African government is attempting to redress the social inequalities which prevailed in the education sector during the apartheid era. One of their efforts has involved the widening of access to diverse groups in society in order to increase participation within the higher education sector. However, many students attempting their higher education studies are academically under prepared. This is mainly due to insufficient life skills, communication skills, numeric skills and literacy skills. The lack of these skills has inspired various international and national higher education institutions to develop academic programmes aimed at bridging the gap that exists between secondary schooling and higher education. Introduction programmes for prospective engineering students have to ensure high-quality curriculum development procedures in order to secure these students’ academic success throughout their engineering studies. This, in turn, leads to quality graduates and addresses the huge shortage experienced by the industry. An overview of the contextual and conceptual views on curriculum development is given against the backdrop of the current higher education legislation in South Africa. The overview regarding curriculum development links the introduction programme curriculum to generic learning outcomes specifically set at the National Qualification Framework Level 4. It suggests the application of continuous assessments, in line with outcomes-based education criteria, together with quality assurance in order to fit the Higher Education Quality Committee and the Engineering Council of South Africa’s accreditation criteria applicable to higher education institutions. During the design and methodological stages, it was established, by means of a theoretical investigation, that the first phase of this study determines whether students that successfully completed the introduction programme perform academically better than students entering the diploma programmes directly. The theoretical investigation also established that the second phase of this study determines if the diploma students dropped out of the programme for reasons other than academic performance. A triangulation approach was used to increase the validity of the empirical part of the study and to enhance the rigorous use of both quantitative and qualitative data. The study results shed light on the need for introduction programmes. In addition, it proposed a curriculum framework for improved engineering introduction programmes at the Vaal University of Technology. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om kurrikulumraamwerk vir oorbruggingsprogram vir ingenieurswese-studente in hoër onderwys te ontwikkel. Die kurrikulumraamwerk is ontwikkel deur middel van gevallestudie wat die implementering van oorbruggingskursusse in die ingenieurswese indringend ondersoek het. Die huidige Suid-Afrikaanse regering poog om die sosio-politieke wanbalanse as nalatenskap van apartheid, uit te wis. Dit word gedoen deur middel van inisiatiewe waarin onder meer hoër onderwys prominente vennoot is wat aan diverse samelewing gelyke geleenthede bied. Die huidige, meer toeganklike bedeling in hoër onderwys in Suid-Afrika het groot toename van studente uit histories agtergeblewe gemeenskappe tot gevolg gehad. Die meeste studente wat in hierdie konteks die hoëronderwyssektor betree, blyk in groot mate onvoorbereid te wees vir hoër onderwys vanweë hul gebrek aan lewens-, kommunikasie-, numeriese en taalvaardighede. Hierdie tendens kom ook op internasionale vlak voor. Dit het inisiatiewe ten opsigte van akademiese ontwikkeling op nasionale sowel as internasionale vlak genoodsaak. Die doel van akademiese ontwikkeling is primêr om die gaping tussen die skool en hoër onderwys te oorbrug. Oorbruggingskursusse moet van hoë gehalte wees om sodoende te kan verseker dat voornemende studente vir hoër onderwys, en vir die doel van hierdie studie meer spesifiek ingenieurstudente, van groter akademiese sukses verseker kan wees. Die suksesvolle implementering van oorbruggingskursusse vir ingenieurswese-studente behoort in groot mate tot beter gehalte gegradueerde te lei en bydrae te lewer tot die vraag na ingenieurswese-studente vir die nywerheidswêreld. Kontekstuele en konsepsuele beskouings ten opsigte van kurrikulumontwikkeling in die hoër onderwys in Suid-Afrika word deur generiese leeruitkomste bepaal. Hierdie uitkomste is op vlak 4 van die land se Nasionale Kwalifikasieraamwerk vasgepen. Dit het ook tot gevolg dat alle programme volgens amptelike Departement van Onderwys-dokumente aan deurlopende assessering onderwerp moet word, dat die gehalte van die kursus onderworpe is aan die gehalteversekeringskriteria van die vi Hoëronderwys se Gehaltekomitee (‘HEQC’) en dat dit moet voldoen aan die vereistes van die Ingenieursraad van Suid-Afrika. Teoretiese raamwerk is tydens die ontwerp- en metodiekstadium van die studie daargestel. Die doel van hierdie eerste fase van die studie was om te bepaal of diplomastudente wat die oorbruggingskursusse suksesvol voltooi het, akademies beter gepresteer het as daardie studente wat nie die oorbruggingskursus gevolg het nie. Die tweede studiefase het bepaal of die diplomastudente hul studies vir redes gestaak het wat moontlik nie met akademiese sukses verband hou nie. Die navorsing het van triangulasie gebruik gemaak, ten einde die doeltreffende gebruik van sowel kwantitatiewe as kwalitatiewe data te verhoog. Die resultate van die studie werp lig op en onderstreep die behoefte aan oorbruggingskursusse. Die navorsing beveel kurrikulumraamwerk aan vir die ontwerp van verbeterde oorbruggingskursusse in die ingenieurswese aan die Vaal Universiteit van Tegnologie.

M.Sc (Aquatic Health) / There has been a recent onslaught of water quality problems in South Africa, with many believing that South Africa is nearing a water crisis in the not so distant future. A Regional Scale Risk Assessment was conducted on the Koekemoer Spruit in order to validate the use of such a risk assessment in the management of small catchments. During the study the use of Artificial Mussels (AMs) in the bio-monitoring of metals were also validated. The Regional Scale Risk Assessment methodology created by Landis (2005) was used during the study. Various lines of evidence were used during the risk assessment process: water quality analysis, invertebrate assessments, diatom assessment and AM and snail assessments. It was found that the Koekemoer Spruit has an impact on the Vaal River with regards to some water quality aspects, especially with regards to an increase in nitrates. It was found that a significant (p<0.05) correlation exists between AMs and Melanoides turbiculata with regards to As, U, Se and Co accumulations. Gold mining was identified as a major stressor source within the system. Other notable sources of stressors within the system included agricultural activities and a golf course. The environment was found to be the endpoint that is at highest risk from the various sources within the system. The in-stream habitat was found to have the highest risk compared to the other identified habitats.

The Ceratium species occurring in the Vaal River since 2000, was identified as Ceratium hirundinella (O.F. Müller) Dujardin as proposed by Van Ginkel et al (2001). Ceratium hirundinella is known to cause problems in drinking water purification and has been penetrating into the final drinking water of Rand Water since 2006. Ceratium hirundinella is associated with many other water purification problems such as disrupting of the coagulation and flocculation processes, blocking of sand filters and algal penetration into the drinking water. Ceratium hirundinella also produce fishy taste and odorous compounds and causes discolouration of the water. The aims of this study were to determine the main environmental factors which are associated with the bloom formation of C. hirundinella in the source water and to investigate the influence of C. hirundinella on the production of potable water. In order to optimise treatment processes and resolve problems associated with high C. hirundinella concentrations during the production of potable water, jar testing and chlorine exposure experiments were performed. Multivariate statistical analyses were performed to determine the main environmental variables behind C. hirundinella blooms. Ten years data (2000 - 2009) from the sampling point C–VRB5T in the Vaal River, (5 km upstream from the Barrage weir) were used for this investigation, because C. hirundinella occurred there frequently during the ten year period. In this study, it was found that C. hirundinella was favoured by high pH, Chemical Oxygen Demand (COD), orthophoshapte (PO4), and silica concentrations, as well as low turbidity and low dissolved inorganic nitrogen (DIN) concentrations. No correlation was found between C. hirundinella and temperature, suggesting that this alga does not occur during periods of extreme warm or extreme cold conditions, but most probably during autumn and spring. The results of the multivariate statistical analysis performed with historical data from Vaalkop dam, indicate that the dinoflagellate C. hirundinella seems to be favoured by low temperature and turbidity, and high DIN, Fe, Methyl–orange alkalinity, Cd, PO4, Conductivity, pH, hardness and SO4 concentrations. In order to optimise treatment processes such as coagulation, flocculation and sedimentation, jar testing experiments were performed to investigate different coagulant chemicals namely: cationic poly–electrolyte only, cationic poly–electrolyte in combination with slaked lime (CaO) and CaO in combination with activated silica. Water from four different sampling localities were chosen to perform the different jar testing experiments: 1) sampling point M–FOREBAY (in the Forebay, connecting the canal to the Zuikerbosch Purification plant) near Vereeniging due to its proximity to the Zuikerbosch treatment plant, 2) M–CANAL_VD (upstream from the inflow of the recovered water from Panfontein) to determine the influence of (if any) the recovered water from Panfontein on Forebay source water, 3) source water from Vaalkop Dam (M–RAW_VAALKOP) and 4) source water from Rietvlei Dam (water from both Vaalkop and Rietvlei Dams contained high concentrations of C. hirundinella at that time of sampling) to determine which coagulant chemical is the most effective in removing high concentrations of C. hirundinella cells during the production of drinking water. The jar testing experiments with Vaalkop Dam and Rietvlei Dam source water (rich with C. hirundinella) indicated that using cationic poly–electrolyte alone did not remove high concentrations of C. hirundinella efficiently. However, when CaO (in combination with cationic poly–electrolyte or activated silica) were dosed to Vaalkop Dam source water a significant decrease of C. hirundinella concentration was observed. This indicates that the C. hirundinella cells were “shocked or stressed” when exposed to the high pH of the CaO, rendering it immobile and thereby enhancing the coagulation and flocculation process. However, when 10 mg/L CaO in combination with poly–electrolyte was dosed to Rietvlei Dam source water the turbidity and chlorophyll–665 results indicated that this coagulant chemical procedure was ineffective in removing algal material from the source water. The jar testing experiments using the cationic poly–electrolyte alone or cationic poly–electrolyte in combination with CaO on M–FOREBAY and M–CANAL_VD source water, showed a decrease in turbidity, chlorophyll–665 concentration, and total algal biomass, with an increase of coagulant chemical. When CaO in combination with activated silica was dosed, the inherent turbidity of the lime increased the turbidity of the Vaalkop Dam, M–FOREBAY and M–CANAL_VD source water to such an extent that it affected coagulation negatively, resulting in high turbidity values in the supernatant. Regardless of the turbidity values, the chlorophyll–665 concentration and total algal biomass (C. hirundinella specifically in Vaalkop Dam source water) decreased significantly when CaO was dosed in combination with activated silica. Therefore it was concluded that a cationic poly–electrolyte alone is a good coagulant chemical for the removal of turbidity, but when high algal biomass occur in the source water it is essential to add CaO to “stress” or “shock” the algae for the effective removal thereof. However, when CaO in combination with activated silica was dosed to Rietvlei Dam source water a decrease in turbidity and chlorophyll–665 concentration was found with an increasing coagulant chemical concentration. These results confirm the fact that coagulant chemicals may perform differently during different periods of the year when water chemistry changes and that certain coagulant chemicals may never be suitable to use for certain source waters. For the effective removal of algae during water purification, it is recommended that cationic poly–electrolyte in combination with CaO are used as coagulant chemical at the Zuikerbosch Water Purification Plant. Turbidity is not a good indication of algal removal efficiency during jar testing experiments. If problems with high algal concentrations in the source water are experienced it is advisable to also determine the chlorophyll–665 concentrations of the supernatant water during the regular jar testing experiments, since it will give a better indication of algal removal. Chlorine exposure experiments were performed on water from Vaalkop Dam (M–RAW_VAALKOP) and Rietvlei Dam source water, to determine the possibility of implementing pre– or intermediate chlorination with the aim to render the cells immobile for more effective coagulation. The chlorine exposure experiments with Vaalkop Dam and Rietvlei Dam source water showed similar results. The chlorine concentration to be dosed as part of pre– or intermediate chlorination will differ for each type of source water as the chemical and biological composition of each water body are unique. When the effect of chlorine on the freshwater dinoflagellate C. hirundinella was investigated, it was found that the effective chlorine concentration where 50 % of Ceratium cells were rendered immobile (EC50) was approximately 1.16 mg/L for Vaalkop Dam source water. For the source water sampled from Rietvlei Dam, it was found that the EC50 was at approximately 0.87 mg/L. Results of analyses to determine the organic compounds in the water after chlorination revealed that an increase in chlorine concentration resulted in increase in total organic carbon concentration (TOC), as well as a slight increase in MIB and trihalomethanes (CHCl3). Pre– or intermediate chlorination seem to be an effective treatment option for the dinoflagellate C. hirundinella to be rendered immobile and thereby assisting in its coagulation process. The use of pre– or intermediate chlorination to effectively treat source waters containing high concentrations of C. hirundinella is a viable option to consider. However, the organic compounds in the water should be monitored and the EC50 value for each source water composition should be determined carefully as to restrict cell lysis and subsequent release of organic compounds into the water. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2012.

The Ceratium species occurring in the Vaal River since 2000, was identified as Ceratium hirundinella (O.F. Müller) Dujardin as proposed by Van Ginkel et al (2001). Ceratium hirundinella is known to cause problems in drinking water purification and has been penetrating into the final drinking water of Rand Water since 2006. Ceratium hirundinella is associated with many other water purification problems such as disrupting of the coagulation and flocculation processes, blocking of sand filters and algal penetration into the drinking water. Ceratium hirundinella also produce fishy taste and odorous compounds and causes discolouration of the water. The aims of this study were to determine the main environmental factors which are associated with the bloom formation of C. hirundinella in the source water and to investigate the influence of C. hirundinella on the production of potable water. In order to optimise treatment processes and resolve problems associated with high C. hirundinella concentrations during the production of potable water, jar testing and chlorine exposure experiments were performed. Multivariate statistical analyses were performed to determine the main environmental variables behind C. hirundinella blooms. Ten years data (2000 - 2009) from the sampling point C–VRB5T in the Vaal River, (5 km upstream from the Barrage weir) were used for this investigation, because C. hirundinella occurred there frequently during the ten year period. In this study, it was found that C. hirundinella was favoured by high pH, Chemical Oxygen Demand (COD), orthophoshapte (PO4), and silica concentrations, as well as low turbidity and low dissolved inorganic nitrogen (DIN) concentrations. No correlation was found between C. hirundinella and temperature, suggesting that this alga does not occur during periods of extreme warm or extreme cold conditions, but most probably during autumn and spring. The results of the multivariate statistical analysis performed with historical data from Vaalkop dam, indicate that the dinoflagellate C. hirundinella seems to be favoured by low temperature and turbidity, and high DIN, Fe, Methyl–orange alkalinity, Cd, PO4, Conductivity, pH, hardness and SO4 concentrations. In order to optimise treatment processes such as coagulation, flocculation and sedimentation, jar testing experiments were performed to investigate different coagulant chemicals namely: cationic poly–electrolyte only, cationic poly–electrolyte in combination with slaked lime (CaO) and CaO in combination with activated silica. Water from four different sampling localities were chosen to perform the different jar testing experiments: 1) sampling point M–FOREBAY (in the Forebay, connecting the canal to the Zuikerbosch Purification plant) near Vereeniging due to its proximity to the Zuikerbosch treatment plant, 2) M–CANAL_VD (upstream from the inflow of the recovered water from Panfontein) to determine the influence of (if any) the recovered water from Panfontein on Forebay source water, 3) source water from Vaalkop Dam (M–RAW_VAALKOP) and 4) source water from Rietvlei Dam (water from both Vaalkop and Rietvlei Dams contained high concentrations of C. hirundinella at that time of sampling) to determine which coagulant chemical is the most effective in removing high concentrations of C. hirundinella cells during the production of drinking water. The jar testing experiments with Vaalkop Dam and Rietvlei Dam source water (rich with C. hirundinella) indicated that using cationic poly–electrolyte alone did not remove high concentrations of C. hirundinella efficiently. However, when CaO (in combination with cationic poly–electrolyte or activated silica) were dosed to Vaalkop Dam source water a significant decrease of C. hirundinella concentration was observed. This indicates that the C. hirundinella cells were “shocked or stressed” when exposed to the high pH of the CaO, rendering it immobile and thereby enhancing the coagulation and flocculation process. However, when 10 mg/L CaO in combination with poly–electrolyte was dosed to Rietvlei Dam source water the turbidity and chlorophyll–665 results indicated that this coagulant chemical procedure was ineffective in removing algal material from the source water. The jar testing experiments using the cationic poly–electrolyte alone or cationic poly–electrolyte in combination with CaO on M–FOREBAY and M–CANAL_VD source water, showed a decrease in turbidity, chlorophyll–665 concentration, and total algal biomass, with an increase of coagulant chemical. When CaO in combination with activated silica was dosed, the inherent turbidity of the lime increased the turbidity of the Vaalkop Dam, M–FOREBAY and M–CANAL_VD source water to such an extent that it affected coagulation negatively, resulting in high turbidity values in the supernatant. Regardless of the turbidity values, the chlorophyll–665 concentration and total algal biomass (C. hirundinella specifically in Vaalkop Dam source water) decreased significantly when CaO was dosed in combination with activated silica. Therefore it was concluded that a cationic poly–electrolyte alone is a good coagulant chemical for the removal of turbidity, but when high algal biomass occur in the source water it is essential to add CaO to “stress” or “shock” the algae for the effective removal thereof. However, when CaO in combination with activated silica was dosed to Rietvlei Dam source water a decrease in turbidity and chlorophyll–665 concentration was found with an increasing coagulant chemical concentration. These results confirm the fact that coagulant chemicals may perform differently during different periods of the year when water chemistry changes and that certain coagulant chemicals may never be suitable to use for certain source waters. For the effective removal of algae during water purification, it is recommended that cationic poly–electrolyte in combination with CaO are used as coagulant chemical at the Zuikerbosch Water Purification Plant. Turbidity is not a good indication of algal removal efficiency during jar testing experiments. If problems with high algal concentrations in the source water are experienced it is advisable to also determine the chlorophyll–665 concentrations of the supernatant water during the regular jar testing experiments, since it will give a better indication of algal removal. Chlorine exposure experiments were performed on water from Vaalkop Dam (M–RAW_VAALKOP) and Rietvlei Dam source water, to determine the possibility of implementing pre– or intermediate chlorination with the aim to render the cells immobile for more effective coagulation. The chlorine exposure experiments with Vaalkop Dam and Rietvlei Dam source water showed similar results. The chlorine concentration to be dosed as part of pre– or intermediate chlorination will differ for each type of source water as the chemical and biological composition of each water body are unique. When the effect of chlorine on the freshwater dinoflagellate C. hirundinella was investigated, it was found that the effective chlorine concentration where 50 % of Ceratium cells were rendered immobile (EC50) was approximately 1.16 mg/L for Vaalkop Dam source water. For the source water sampled from Rietvlei Dam, it was found that the EC50 was at approximately 0.87 mg/L. Results of analyses to determine the organic compounds in the water after chlorination revealed that an increase in chlorine concentration resulted in increase in total organic carbon concentration (TOC), as well as a slight increase in MIB and trihalomethanes (CHCl3). Pre– or intermediate chlorination seem to be an effective treatment option for the dinoflagellate C. hirundinella to be rendered immobile and thereby assisting in its coagulation process. The use of pre– or intermediate chlorination to effectively treat source waters containing high concentrations of C. hirundinella is a viable option to consider. However, the organic compounds in the water should be monitored and the EC50 value for each source water composition should be determined carefully as to restrict cell lysis and subsequent release of organic compounds into the water. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2012.