A dataset representing the impact of cyanide on the fatty acid profile of Scenedesmus obliquus
- Mekuto, Lukhanyo, Musingadi, Dakalo
- Authors: Mekuto, Lukhanyo , Musingadi, Dakalo
- Date: 2019
- Subjects: Scenedesmus obliquus , Biodegradation , Free cyanide
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/399936 , uj:33356 , Citation: Mekuto, L. & Musingadi, D. 2019. A dataset representing the impact of cyanide on the fatty acid profile of Scenedesmus obliquus. , DOI: https://doi.org/10.1016/j.dib.2019.103900
- Description: Abstract: Please refer to full text to view abstract.
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- Authors: Mekuto, Lukhanyo , Musingadi, Dakalo
- Date: 2019
- Subjects: Scenedesmus obliquus , Biodegradation , Free cyanide
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/399936 , uj:33356 , Citation: Mekuto, L. & Musingadi, D. 2019. A dataset representing the impact of cyanide on the fatty acid profile of Scenedesmus obliquus. , DOI: https://doi.org/10.1016/j.dib.2019.103900
- Description: Abstract: Please refer to full text to view abstract.
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Bio-refining of crude oil using microorganisms isolated from petroleum refinery waste water
- Authors: Mrwebi, Phumla
- Date: 2016
- Subjects: Petroleum refineries , Green technology , Petroleum - Environmental aspects , Hydrocarbons , Biodegradation
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/226069 , uj:22848
- Description: M.Tech. (Biotechnology) , Abstract: The petroleum industry contributes significantly in greenhouse gas (GHG) emissions such as carbon dioxide which amounts to 97.67% of the total GHG emission during production while methane contributes about 2.25% and nitrous oxide contributes about 0.08%. Greenhouse gases are a major cause for drastic climate changes facing the world today. The effects of climate change are quite visible as the world is experiencing an increase in the average global temperature, accelerated melting of icebergs during summer and unusual precipitation patterns. These effects of climate change may affect the ecosystems as their effects are life threating. The aim of this study was to isolate and identify microorganisms that inhabit petroleum refinery waste water and to assess their ability to hydrolyse complex hydrocarbons present in crude oil to simpler hydrocarbons found in refined petroleum. Five bacterial strains were isolated using serial dilutions, spread and streaked plate techniques. Colonies were selected based on colony morphology and Gram stain characteristics. Characterization of bacteria was accomplished by 16S rRNA gene sequencing. According to sequencing data, the isolates were identified as Bacillus thuringiensis, Staphylococcus warneri, Citrobacter amalonaticus, Acinetobacter tandoii and Bacillus sp. These microorganisms were inoculated in minimal salt media containing 5% of crude oil at pH 7 and temperature 30oC at 140 rpm in a shaking incubator in order to study microbial degradation patterns.. The biodegradation studies were carried over a period of five days and a volume of 1mL of sample was aseptically drawn from the flasks on each day of the incubation period. Bacterial cells were removed using 0.22 μm filters. The breakdown products of crude oil were solubilized by adding 1ml of chloroform into 1mL of the sample. Biodegradation products were analysed by GCxGC-ToF-MS and show that all the isolates were capable of hydrolysing the crude oil. A. tandoii was the most efficient microorganism amongst the 4 isolates as it was the only isolate that was able to transform high molecular weight hydrocarbons (C30 and above) and produced significant amounts of new compounds whereas C. amalonaticus and S. warneri could only transform short and medium chain hydrocarbons (C1-C20), B. thuringiensis was able to transform compounds with chain lengths ranging between C1 and C30. From these observations A. tandoii and B. thuringiensis would be more applicable in bio-refining of crude oil as they are able to transform medium and heavy molecular weight hydrocarbons into short chain hydrocarbons which are normally found in refined petroleum hydrocarbons such as gasoline, kerosene and diesel fuel.
- Full Text:
- Authors: Mrwebi, Phumla
- Date: 2016
- Subjects: Petroleum refineries , Green technology , Petroleum - Environmental aspects , Hydrocarbons , Biodegradation
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/226069 , uj:22848
- Description: M.Tech. (Biotechnology) , Abstract: The petroleum industry contributes significantly in greenhouse gas (GHG) emissions such as carbon dioxide which amounts to 97.67% of the total GHG emission during production while methane contributes about 2.25% and nitrous oxide contributes about 0.08%. Greenhouse gases are a major cause for drastic climate changes facing the world today. The effects of climate change are quite visible as the world is experiencing an increase in the average global temperature, accelerated melting of icebergs during summer and unusual precipitation patterns. These effects of climate change may affect the ecosystems as their effects are life threating. The aim of this study was to isolate and identify microorganisms that inhabit petroleum refinery waste water and to assess their ability to hydrolyse complex hydrocarbons present in crude oil to simpler hydrocarbons found in refined petroleum. Five bacterial strains were isolated using serial dilutions, spread and streaked plate techniques. Colonies were selected based on colony morphology and Gram stain characteristics. Characterization of bacteria was accomplished by 16S rRNA gene sequencing. According to sequencing data, the isolates were identified as Bacillus thuringiensis, Staphylococcus warneri, Citrobacter amalonaticus, Acinetobacter tandoii and Bacillus sp. These microorganisms were inoculated in minimal salt media containing 5% of crude oil at pH 7 and temperature 30oC at 140 rpm in a shaking incubator in order to study microbial degradation patterns.. The biodegradation studies were carried over a period of five days and a volume of 1mL of sample was aseptically drawn from the flasks on each day of the incubation period. Bacterial cells were removed using 0.22 μm filters. The breakdown products of crude oil were solubilized by adding 1ml of chloroform into 1mL of the sample. Biodegradation products were analysed by GCxGC-ToF-MS and show that all the isolates were capable of hydrolysing the crude oil. A. tandoii was the most efficient microorganism amongst the 4 isolates as it was the only isolate that was able to transform high molecular weight hydrocarbons (C30 and above) and produced significant amounts of new compounds whereas C. amalonaticus and S. warneri could only transform short and medium chain hydrocarbons (C1-C20), B. thuringiensis was able to transform compounds with chain lengths ranging between C1 and C30. From these observations A. tandoii and B. thuringiensis would be more applicable in bio-refining of crude oil as they are able to transform medium and heavy molecular weight hydrocarbons into short chain hydrocarbons which are normally found in refined petroleum hydrocarbons such as gasoline, kerosene and diesel fuel.
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Biodegradable polymer composites : synthesis, properties and application in water purification
- Authors: Vilakati, Gcina Doctor
- Date: 2012-05-02
- Subjects: Polymer biodegradation , Water purification , Biodegradation , Composite materials , Polymer deterioration , Heavy metals - Absorption and adsorption
- Type: Thesis
- Identifier: http://ujcontent.uj.ac.za8080/10210/371689 , uj:2232 , http://hdl.handle.net/10210/4672
- Description: M.Sc. , The addition of lignocellulosic fibres to thermoplastic polymers is known to increase the toughness of the polymers but it compromises the tensile strength. On the other hand, inorganic fillers like TiO2 are known to improve the tensile strength of polymers. These plant fibres have been used as adsorbents of metal pollutants in water. Best results were obtained when such materials were ground to fine powder but due to low density, the fibres float and form aggregates in water. Being highly biodegradable in nature makes plant fibres unsuitable for water treatment over lengthy periods of time. They cannot be used as standalone materials. Mixing these adsorbents with polymers, which cannot only act as support for the adsorbents but also disperse the fibres within it thus preventing leaching, is a cause for concern. This study was aimed at fabricating plant fibre-polymer composites that will have improved mechanical and thermal properties. These composites were to be tested for their ability to be used as metal ion adsorbents. The composites were fabricated using a melt-mix compounding method. Two thermoplastic polymers, EVA and PCL were each mixed with either lignin or SCB and TiO2 in different ratios. A rheomex mixer coupled with a single screw extruder which was attached to a sheet die was used to synthesise the composites. TGA and DSC were used for thermal propagation while the mechanical properties were investigated using an instron. Metal ion adsorption measurements were analysed using an atomic absorption spectrometer (AAS). These adsorbents were used to remove Cr(VI), Cr(III) and Pb(II), varying different environmental parameters like pH, concentration, time and adsorbent at constant temperature. The reinforcing effect of both lignin and SCB resulted to poor thermal and mechanical properties. This was shown by a decrease in onset degradation temperature and the tensile and toughness of the composites compared to the neat polymers. The incorporation of TiO2 on SCB-EVA composites, however, improved the mechanical strength and resulted in a thermally stable composite compared to counterpart composites without TiO2. This observation was surpassed at high filler loading as the addition of TiO2 resulted in a decrease of the properties. For the tensile strength, neat EVA recorded 11.35 MPa while 2% TiO2-EVA registered 12.49 MPa for example. For the same composite, the onset degradation temperature for EVA was 353 oC but shifted to 368 oC after the addition of TiO2. At higher filler loading, no effect was observed when adding TiO2.
- Full Text:
- Authors: Vilakati, Gcina Doctor
- Date: 2012-05-02
- Subjects: Polymer biodegradation , Water purification , Biodegradation , Composite materials , Polymer deterioration , Heavy metals - Absorption and adsorption
- Type: Thesis
- Identifier: http://ujcontent.uj.ac.za8080/10210/371689 , uj:2232 , http://hdl.handle.net/10210/4672
- Description: M.Sc. , The addition of lignocellulosic fibres to thermoplastic polymers is known to increase the toughness of the polymers but it compromises the tensile strength. On the other hand, inorganic fillers like TiO2 are known to improve the tensile strength of polymers. These plant fibres have been used as adsorbents of metal pollutants in water. Best results were obtained when such materials were ground to fine powder but due to low density, the fibres float and form aggregates in water. Being highly biodegradable in nature makes plant fibres unsuitable for water treatment over lengthy periods of time. They cannot be used as standalone materials. Mixing these adsorbents with polymers, which cannot only act as support for the adsorbents but also disperse the fibres within it thus preventing leaching, is a cause for concern. This study was aimed at fabricating plant fibre-polymer composites that will have improved mechanical and thermal properties. These composites were to be tested for their ability to be used as metal ion adsorbents. The composites were fabricated using a melt-mix compounding method. Two thermoplastic polymers, EVA and PCL were each mixed with either lignin or SCB and TiO2 in different ratios. A rheomex mixer coupled with a single screw extruder which was attached to a sheet die was used to synthesise the composites. TGA and DSC were used for thermal propagation while the mechanical properties were investigated using an instron. Metal ion adsorption measurements were analysed using an atomic absorption spectrometer (AAS). These adsorbents were used to remove Cr(VI), Cr(III) and Pb(II), varying different environmental parameters like pH, concentration, time and adsorbent at constant temperature. The reinforcing effect of both lignin and SCB resulted to poor thermal and mechanical properties. This was shown by a decrease in onset degradation temperature and the tensile and toughness of the composites compared to the neat polymers. The incorporation of TiO2 on SCB-EVA composites, however, improved the mechanical strength and resulted in a thermally stable composite compared to counterpart composites without TiO2. This observation was surpassed at high filler loading as the addition of TiO2 resulted in a decrease of the properties. For the tensile strength, neat EVA recorded 11.35 MPa while 2% TiO2-EVA registered 12.49 MPa for example. For the same composite, the onset degradation temperature for EVA was 353 oC but shifted to 368 oC after the addition of TiO2. At higher filler loading, no effect was observed when adding TiO2.
- Full Text:
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