No description available.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2012. / The Diep River is approximately 80 km in length and runs through agricultural land and urban parts of greater Cape Town, South Africa before entering the Atlantic Ocean, via an estuary. Generally, metal pollution in South African rivers is not well documented and using plants to monitor metal bioaccumulation is even less documented. The aim of this study was to investigate aluminium, iron, copper and zinc metal pollution in the Diep River and bioaccumulation of these metals in the leaves and stems of the submerged macrophyte Ceratophyllum demersum L. Furthermore, the effects of bioaccumulated metals on membrane integrity and chlorophyll content of these plants were investigated. Site 1 was situated in the upper reaches of the river adjacent to agricultural land, while site 2 was in an urban area, where industrial activities predominate. C. demersum (from an uncontaminated source) were introduced into the river at the two sites and compared with one another on a fortnightly basis over a 12 week period. Plants at site 2 were also compared to existing plants that were naturally growing at the site. Comparisons were also made between leaves and stems of the plants, to establish the organ of preference regarding metal accumulation and storage. Samples were digested with nitric acid and an ICP-MS was used to analyse metal concentrations in the water, sediment and plants. Chlorophyll extraction was done using dimethyl sulphoxide (DMSO) and the absorbance values determined using a spectrophotometer. Chlorophyll a, chlorophyll b and total chlorophyll contents were recorded and compared. Cell membrane integrity was determined by leaving plants for 24 hours in deionised water and measuring electrical conductivity and solutes (sodium, calcium, potassium and magnesium) before and after placement of the plants.

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2008 / The lower Diep River is a major freshwater ecosystem in the Western Cape. The river is surrounded by many possible sources of metal pollution such as an oil refinery, industries, a sewage treatment plant and a landfill site. However, metal contamination levels have not been monitored in this river. The aim of the study was therefore to monitor the degree of metal pollution in the lower Diep River, over a period of one year, and to investigate the use of the sedge Bolboschoenus maritimus, as biomonitor species. Three sampling sites were used. Site I was located in the vicinity of landfill sites and farm areas. Site 2 was located I km upstream from a wetland reserve, surrounded by heavy industrial activity and continuous residential developments. Site 3 was located downstream of the wetland reserve, 2 km from the river mouth. The following metals were investigated: aluminium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. Water and sediment samples were collected every two months for a period of one year. Plant specimens (roots, leaves and stems) were collected seasonally from site I and site 3. Samples were acid digested and metal analysis was done using an ICP - AES (Inductively Coupled Plasma- Atomic Emission Spectrophotometer). Statistical analyses were done to investigate possible differences between the sites, sampling occasions and various plant components.

Thesis (MScAgric)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The study was conducted in the Western Cape Province to investigate the effect of soil preparation on selected soil physical properties. This study was necessitated by the negative effects that high soil bulk density has on the growth and production of a vine. Soil preparation in South Africa are applied to remove root limiting layers in the subsoil and to create a larger soil volume for root growth. The question is whether it is always necessary because of the destruction of macropore structure and also the high costs that is involved. The study includes different soil forms, different depths of tillage, different tillage operations and also the change of soil physical properties with time. Soil physical properties that was investigated include, bulk density (cloth method), infiltration (mini disk infiltrometer and double ring infiltrometer), shear strength (pocket vane tester), soil strength (penetrometer) and root distribution (profile wall method). The main finding was that the positive effects of soil preparation were still clear after 25 years. The bulk density, shear strength, penetration resistance and infiltration with the double ring infiltrometer of the deeper soil preparation practices were considerably lower than those of undisturbed soil. Soil preparation shallower than 60 cm recompacted more than the deeper tillage treatments. Hydraulic conductivity with the mini disk infiltrometer yielded mixed results. This was mainly because measurements represented hydraulic conductivity through the whole profile and therefore can be influenced by many factors. Root distribution has increased with depth of tillage and the effect was clear at Nietvoorbij in the deeper (> 60 cm) soil preparation treatments. There were no significant difference between the two soil preparation methods (delve plough and soilmix) at Kanonkop, although the effect of secondary compaction by the soilmix was quite clear. Recompaction over a year was clear in the 2009 and 2010 tillage treatments at Broodkraal. The methods that were used to determine the soil physical properties have all yield good results. At all the sites the tillage treatments generally yielded better results than the undisturbed soils. It was also clear that the longer the time after tillage the smaller become the difference between the tillage treatments and the undisturbed soils. Recompaction did occur and therefore soil preparation might possibly be applied again before new vines wants to be planted. / AFRIKAANSE OPSOMMING: Die studie is in die Wes-Kaap Provinsie gedoen om die effek van grondvoorbereiding op geselekteerde grondfisiese eienskappe te ondersoek. Hierdie studie is genoodsaak deur die nadelige gevolge wat hoë gronddigthede op die groei en produksie van ’n wingerdstok het. Grondvoorbereiding in Suid-Afrika word toegepas om beperkende lae in die ondergrond te verwyder en sodoende ‘n groter grondvolume vir wortelgroei beskikbaar te stel. Die vraag is egter of dit altyd noodsaaklik is weens die vernietiging van voorkeur vloeikanale en die hoë kostes wat daarmee gepaard gaan. Die studie sluit verskillende grondvorms, verskillende dieptes van bewerking en verskillende tipes bewerking in asook hoe die toestande met verloop van tyd verander. Grondfisiese eienskappe wat ondersoek is, sluit in: bulkdigtheid (kluitmetode), infiltrasie (“mini disk” - en dubbelring infiltrometer), skuifsterkte (skroefbladmeter), grondsterkte (penetrometer) en wortelverspreidings (profielwand metode). Die studie is uitgevoer by drie verskillende proeflokaliteite, nl. Nietvoorbij, Kanonkop en Broodkraal. Die vernaamste bevindings was dat die grondvoorbereidingsbehandelings se voordelige effek oor die langtermyn, na 25 jaar, steeds duidelik waarneembaar was. Die bulkdigtheid, skuifsterkte, penetrasieweerstand en infiltrasie met dubbelring infiltrometer van die dieper grondbewerkingspraktyke was aansienlik laer as die kontrole behandelings (onversteurde grond) gewees. Die grondvoorbereidingsaksies vlakker as 60 cm het tot ʼn mate weer herverdig. Hidrouliese geleiding met minidisk infiltrometer het baie wisselvallige resultate opgelewer. Dit is hoofsaaklik omdat die meting die geleiding deur die hele profiel verteenwoordig en daar baie faktore is wat dit kan beïnvloed. Die wortelverspreiding het met diepte van grondbewerking toegeneem en die langtermyn voordelige effek was duidelik by Nietvoorbij in die dieper (> 60 cm) grondvoorbereidingsbehandelings sigbaar. Die twee grondvoorbereidingspraktyke (dolbewerking en “soilmix”) by Kanonkop het nie betekenisvol van mekaar verskil nie, alhoewel die effek van sekondêre kompaksie soos veroorsaak deur die “soilmix” implement, duidelik was. Herverdigting oor die tydperk van ’n jaar was duidelik tussen die 2009- en 2010 bewerking by Broodkraal. Die metingsmetodes waarmee die grondfisiese eienskappe ondersoek is, het almal goeie resultate gelewer. By al die proeflokaliteite het die bewerkingsbehandelings oor die algemeen beter resultate as die kontrole-behandelings (onversteur) gelewer. Hoe langer die tydperk na grondvoorbereiding hoe kleiner was die verskil tussen die bewerkingsbehandelings en die kontrole. Herverdigting het wel voorgekom en daarom sal grondvoorbereiding moontlik weer toegepas moet word wanneer nuwe aanplantings gemaak word.

Computed tomography is one of the most evolving fields of modern radiology. The current CT applications permit among other things angiography, 3D image reconstructions, material decomposition and tissue characterization. CT is an important tool in the assessment of specific patient populations prior to an invasive or surgical procedure. The aim of this dissertation was to demonstrate the decisive role of CT with 3D-image reconstructions in haemodialysis patients scheduled to undergo fistulography, in patients undergoing surgical breast reconstructions with a perforator flap and in patients with complicated renal calculi scheduled to undergo percutaneous nephrolithotomy. CT Angiography with 3D image reconstructions was performed in 31 patients with failing arteriovenous fistulas and grafts, illustrating the vascular anatomy in a comprehensive manner in 93.5% of the evaluated segments and demonstrating a sensitivity of 95% compared to fistulography. In 59 mastectomy patients scheduled to undergo reconstructive breast surgery with a deep inferior epigastric perforator flap, the preoperative planning with CT Angiography with 3D image reconstructions of the anterior abdominal wall providing details of its vascular supply, reduced surgery time significantly (p< 0.001) and resulted in fewer complications. Dual Energy CT Urography with advanced image reconstructions in 31 patients with complicated renal calculi scheduled to undergo PNL, resulted in a new method of material characterisation (depicting renal calculi within excreted contrast) and in the possibility of reducing radiation dose by 28% by omitting the nonenhanced scanning phase. Detailed analysis of the changes renal calculi undergo when virtually reconstructed was performed and a comparison of renal calculi number, volume, height and attenuation between virtual nonenhanced and true nonenhanced images was undertaken. All parameters were significantly underestimated in the virtual nonenhanced images. CT with 3D-reconstructions is more than just “flashy images”. It is crucial in preoperative planning, optimizes various procedures and can reduce radiation dose.

Thesis (DTech (Biomedical Technology))--Cape Peninsula University of Technology, 2008. / Includes bibliographies. Also available online.

Thesis (DTech (Biomedical Technology))--Cape Peninsula University of Technology, 2008. / Bibliography: leaves 208-236. Also available online.

Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2012. / Perfluorinated compounds (PFCs), in particular perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have been found in aquatic environments throughout the world. Recent studies have reported that owing to their bioaccumulative nature, PFCs may also be present in various water sources, resulting in human and wild-life exposure. Although, these PFCs usually occur at low concentration levels, their presence in the environment has nevertheless been a concern in both developed and developing countries, since water remains an important natural resource for most living species. Water and sediment from rivers are one of the matrices in which PFC contamination is studied, since rivers receive water from various sources. However, limited studies have been conducted in South Africa on PFC contamination of river water and sediments. Although PFCs are sometimes unintentionally released into the environment, the concentration and type of PFCs that contaminate water sources vary among countries and depend on the types of industry releasing them into the environment, suggesting that PFC contamination patterns can be expected to differ from country to country, with PFOA and PFOS being the predominant perfluorinated contaminants. The aim of this study was therefore to determine the concentration of PFOS and PFOA in riparian wetlands of the Western Cape, focusing on the Eerste, Diep and Salt rivers, which are the primary rivers in the largest catchment areas of the Western Cape, South Africa.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Biomedical Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2008 / The quality of South Africa’s water sources is fast deteriorating due to an influx of pollutants from industrial and agricultural areas. In addition, urbanisation has led to the establishment of informal settlements along river systems. This study focuses on the importance of maintaining water quality and the management of water resources in order to ensure its sustainability in South Africa. The primary aim of this study was to determine the extent of bacterial contamination in three rivers namely the Berg-, Plankenburg- and Diep Rivers in the Western Cape, South Africa and to investigate the application of a bioremediation system as a possible treatment technology. Several aspects contributing to the contamination were addressed and different approaches were studied and reviewed. In all three rivers, four sampling sites were identified, which were sampled over a period of 9 to 12 months. Contamination levels for the three rivers were evaluated by applying various enumeration techniques, which could provide an accurate indication of the planktonic bacterial pollution load in the river systems. The Most Probable Number (MPN) technique was used to determine the level of faecal coliforms and E. coli. The highest MPN, faecal coliform and E. coli counts of 3.5 x 107 micro-organisms/100 m , 3.5 x 107 micro-organisms/100 m and 1.7 x 107 micro-organisms/100 m , respectively, were recorded at Site B2 in week 37 in the Berg River. Results showed that in all the river water sampled and evaluated, the total MPN count mostly exceeded the maximum limit of 2000 micro-organisms/100 m (SABS, 1984) stipulated for river water throughout the study period. The heterotrophic plate count (HPC) method was used to determine the number of culturable micro-organisms in planktonic samples, while the flow cytometry (FCM) and epifluorescence microscopy (EM) with different fluorochromes (Acridine orange and BacLight™ Live/Dead stain) were employed to evaluate total bacterial counts in planktonic (water) samples. The highest HPC at the various sites sampled was 1.04 x 106 micro-organisms/m (Berg River, Site B2), 7.9 x 104 micro-organisms/m (Plankenbrug River, Site A) and 1.7 x 105 micro-organisms/m (Diep River, Site B). Total cell counts as high as 3.7 x 107 micro-organism/m (Berg River, Site B2), 5.5 x 108 micro-organism/m (Plankenburg River, Site D) and 2.5 x 109 micro-organisms/m (Diep River, Site B) were obtained by the FCM technique, which were significantly (p < 0.05) higher than the total counts obtained by epifluorescence microscopy. The results thus show that the FCM technique was the most reliable method for determining the total cell count in river water samples. This technique makes use of computer software whereas epifluorescence microscopy involves manual counting which may lead to human error. In addition, the impact of residential, agricultural and industrial areas situated along these rivers was also investigated. Even though exact point sources of pollution could not be determined, it was found that all the sources, such as the storm water drainage pipes, the industrial as well as the agricultural areas, could contribute to increased MPN, heterotrophic and total bacterial counts. This study also aimed at investigating and comparing the microbial contamination levels at various sites in the Plankenburg and Diep Rivers in the Western Cape, South Africa. Sampling of sites along the Plankenburg River started in June 2004 and continued for a period of one year until June 2005. Sampling of the Diep River sites started in March 2005 and continued for a period of nine months until November 2005. Faecal coliform (FC) and E. coli (EC) counts were determined by means of the Most Probable Number technique, the number of culturable cells were determined using the heterotrophic plate count (HPC) technique and total microbial counts were evaluated by Flow cytometric analysis (FCM). The highest microbial counts for the Plankenburg River were observed at site B where the highest MPN, FC, E. coli and total FCM counts of 9.2 x 106 (week 14), 3.5 x 106 (week 39) and 3.5 x 106 micro-organisms/100 m (week 39) and 2.1 x 108 micro-organisms/m (weeks 1 and 39) respectively, were recorded. The highest HPC recorded for the Plankenburg River was 7.9 x 106 micro-organisms/100 m (week 44, site A). Site B is situated close to an informal settlement where waste effluents from storm water drainage pipes enter the river system. In addition, other possible contamination sources included agricultural (site A) and industrial (site C) areas bordering the Plankenburg River. The highest total MPN, FC and E. coli counts in the Diep River were 5.4 x 106 (week 23) and 1.6 x 106 micro-organisms/100 m [FC and E. coli, respectively (both in week 23)], recorded at site B. The highest HPC and total FCM counts of 1.7 x 107 micro-organisms/100 m (week 14) and 2.5 x 109 microorganisms/ m (week 23), respectively, were also recorded at site B. This site was identified as the most contaminated site along the Diep River and served as an accumulation point for waste effluents from the residential and industrial areas, which included paint and machine manufacturers. Other sources situated along the Diep River included storage and maintenance facilities for steel containers, a waste water treatment plant and an oil-refinery. Most of the bacterial counts obtained for the Plankenburg and Diep Rivers exceeded the accepted maximum limit for river water for most of the sampling period. Bacterial species from the Berg- and Plankenburg Rivers were isolated and identified. The presence of various Enterobacteriaceae species isolated at all the sites in both rivers confirmed faecal contamination of these water sources over the entire sampling period. Opportunistic pathogens such as Klebsiella sp., Serratia sp., Enterobacter sp., Shewanella sp., Aeromonas sp., Pseudomonas sp., Acinetobacter sp. and Citrobacter freundii as well as pathogens such as Bacillus cereus and B. anthracis were also identified in both river systems. All the respective articles are presented in the required format of the journal in which the article has been published or submitted to.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Biomedical Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2008 / River systems can become contaminated with micro-organisms and metals and the routine monitoring of these rivers is essential to control the occurrence of these contaminants in water bodies. This study was aimed at investigating the metal contamination levels in the Berg-, Plankenburg- and Diep Rivers in the Western Cape, South Africa, followed by the remediation of these rivers, using bioreactor systems. Sampling sites were identified and samples [water, sediment and biofilm (leaves, rocks and glass, etc.)] were collected along the Berg- and Plankenburg Rivers from May 2004 to May 2005 and for the Diep River, from February 2005 to November 2005. The concentrations of aluminium (Al), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) were determined using the nitric acid digestion method and analysed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). For the Berg River, the highest concentrations in water samples were recorded for Al, Mn and Fe at the agricultural area (Site A – chapter 2). In the sediment and biofilm samples, the highest metal concentrations were once again recorded for Al and Fe. The concentrations of Al and Fe were significantly higher (p < 0.05) than than Cu, Zn, Pb, Ni and Mn in water, sediment and biofilm samples, and were mostly higher than the quality guidelines recommended by the Department of Water Affairs and Forestry (DWAF, 1996) and the Canadian Council for the Ministers of the Environment (CCME, 2001). Possible sources of contamination in the Berg River could be due to the leaching or improper discarding of household waste from the informal- and established residential areas, as well as the improper discarding of pesticides at the agricultural area. For both the Plankenburg and Diep Rivers the Al and Fe concentrations were higher than all the other metals analysed for in sediment and water samples. The highest concentrations recorded in the Plankenburg River was 13.6 mg.l-1 (water - Week 18, Site B) and 15 018 mg.kg-1 (sediment - Week 1, Site C) for Al and 48 mg.l-1 (water - Week 43, Site A) and 14 363.8 mg.kg-1 (sediment - Week 1, Site A) for Fe. The highest concentrations recorded in the Diep River was 4 mg.l-1 (water - Week 1, Site A) and 19 179 mg.kg-1 (sediment - Week 1, Site C) for Al and 513 mg.l-1 (water - Week 27, Site A) and 106 379.5 mg.kg-1 (sediment - Week 9, Site C) for Fe. For most of the metals analysed the concentrations were higher than the recommended water quality guidelines as stipulated by the Department of Water Affairs and Forestry (DWAF, 1996b), the Canadian Council for the Ministers of the Environment (CCME, 2001) and the ‘World average’ (Martin and Windom, 1991). Point sources of pollution could not conclusively be identified, but the industrial and residential areas could have influenced the increased concentrations. Metal concentrations should be routinely monitored and the guidelines should be updated and revised based on the current state of the rivers and pollution influences. Micro-organisms isolated from flow cells after exposure to varying metal concentrations were investigated for possible metal-tolerance. A site where high metal concentrations were recorded along the Plankenburg River was investigated. The micro-organisms isolated from the flow cells were cultured and identified using the Polymerase Chain Reaction (PCR) technique, in conjunction with universal 16SrRNA primers. The phylogeny of the representative organisms in GenBank, were analysed using the Neighbour-joining algorithm in Clustal X. After exposure, the channels were stained with the LIVE/DEAD BacLightTM viability probe and visualised using Epifluorescence Microscopy. The results revealed that when exposed to the highest concentrations of Al (900 mg.l-1), Fe (1000 mg.l-1), Cu (10 mg.l-1) and Mn (80 mg.l-1), the percentage of dead cells increased, and when exposed to the lowest concentrations of Al (10 mg.l-1), Cu (0.5 mg.l-1), Mn (1.5 mg.l-1) and Zn (0.5 mg.l-1), no significant differences could be distinguished between live an dead cells. When exposed to the highest concentrations of Zn (40 mg.l-1) and Ni (20 mg.l-1), no significant differences between the live and dead cell percentages, were observed. The phylogenetic tree showed that a diverse group of organisms were isolated from the flow cells and that some of the isolates exhibited multiple metal resistance (Stenotrophomonas maltophilia strain 776, Bacillus sp. ZH6, Staphylococcus sp. MOLA:313, Pseudomonas sp. and Delftia tsuruhatensis strain A90 exhibited tolerance to Zn, Ni, Cu, Al, Fe), while other isolates were resistant to specific metals (Comamonas testosteroni WDL7, Microbacterium sp. PAO-12 and Sphingomonas sp. 8b-1 exhibited tolerance to Cu, Ni and Zn, respectively, while Kocuria kristinae strain 6J-5b and Micrococcus sp. TPR14 exhibited tolerance to Mn). The efficiency of two laboratory-scale and one on-site bioreactor system was evaluated to determine their ability to reduce metal concentrations in river water samples. The laboratory-scale bioreactors were run for a two-week and a three-week period and the on-site bioreactor for a period of ten weeks. Water (all three bioreactors) and bioballs (bioreactor two and on-site bioreactor) were collected, digested with 55% nitric acid and analysed using ICP-AES. The final concentrations for Al, Ni and Zn (bioreactor one) and Mn (bioreactor two), decreased to below their recommended concentrations in water samples. In the on-site, six-tank bioreactor system, the concentrations for Fe, Cu, Mn and Ni decreased, but still exceeded the recommended concentrations. The concentrations recorded in the biofilm suspensions removed from the bioballs collected from bioreactor two and the on-site bioreactor, revealed concentrations higher than those recorded in the corresponding water samples for all the metals analysed, except Fe. The bioballs were shown to be efficient for biofilm attachment and subsequent metal accumulation. The species diversity of the organisms isolated from the bioreactor (bioreactor two) experiment after three days (initial) differed from the organisms isolated after 15 days (final). Hydrogenophaga sp., Ochrobactrum sp, Corynebacterium sp., Chelatobater sp. and Brevundimonas sp. were present only at the start of the bioreactor experiment. The surviving populations present both in the beginning and at the end of the bioreactor experiment belonged predominantly to the genera, Pseudomonas and Bacillus. Metal-tolerant organisms, such as Bacillus, Pseudomonas, Micrococcus and Stenotrophomonas, amongst others, could possibly be utilised to increase the efficiency of the bioreactors. The bioreactor system should however, be optimised further to improve its efficacy.