The independent high rate algal pond as a unit operation in tertiary wastewater treatment
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
- Authors: Clark, Stewart James
- Date: 2002
- Subjects: Algae -- Biotechnology , Sewage -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4092 , http://hdl.handle.net/10962/d1007805
- Description: The development of the High Rate Algal Pond (HRAP) as an independent tertiary treatment unit operation for phosphate and nitrate removal is reported. A novel Integrated Algal Ponding System (lAPS) design is proposed for nutrient removal from the effluents of both a conventional domestic sewage treatment plant and from an Advanced Integrated Wastewater Ponding System (AIWPS). The viability of an independently operated HRAP has been identified and termed the Independent High Rate Algal Pond (l-HRAP). A 500 m² pilot 1- HRAP was operated in such a way as to facilitate the precipitation of calcium phosphate, known to be controlled by pH (greater than 9.4) and resulting in final phosphate levels of less than 1 mg.L⁻¹ as P0₄-P. The incorporation of the I-HRAP into a denitrification process was also investigated. Continuously fed column reactors, utilising algal biomass as a carbon source, showed that the heterotrophic bacterial community dominant in the anaerobic algal sludge were denitrifying the nitrate in the feed. It was demonstrated that as the cultures were stressed (using increased nitrate concentrations, anaerobiosis and light starvation) total polysaccharide (TPS) concentrations increased, with a notable increase 111 the exopolysaccharide (EPS) fraction. These experiments corroborated the hypothesis that harvested microalgal biomass can be manipulated to produce, and release, exopolymeric substances under stress conditions, and which may serve as carbon source for denitrification. In both batch flask studies and in laboratory-scale reactor systems, harvested microalgal biomass from an HRAP was shown to produce exopolymeric substances under stress conditions. Initial high loading-rates of greater than 20 mg.L⁻¹ NO₃-N resulted in double the amount of exopolysaccharide production than in flasks with initial low loading-rates (less than 5 mg.L⁻¹ NO₃-N). Making use of an upflow anaerobic sludge blanket-type degrading-bed reactor, and an anaerobic, flooded trickle filter (ANTRIC) receiving HRAP effluent, the relationship between denitrification and the changes in polysaccharide content was investigated. This phenomenon has considerable beneficial implications in biological wastewater treatment systems where high nitrate concentration in the final effluent is a potential mitigating factor. Identification of the heterotrophic bacteria active in the denitrification process was attempted. This study presents a first report on the development and operation of the I-HRAP and has been followed by a technical-scale pilot plant evaluation of the process in the tertiary treatment of domestic wastewaters.
- Full Text:
- Date Issued: 2002
Towards the performer-creator in contemporary mime, with specific reference to the physical theatre of Andrew Buckland, 1988-2000
- Authors: Murray, Robert Ian
- Date: 2002
- Subjects: Buckland, Andrew , Mime , Mimes -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2158 , http://hdl.handle.net/10962/d1007720
- Description: Part one of this thesis investigates the conceptualisation of the performer-creator and its relevance in late twentieth century physical performance by examining some of the theoretical, but mainly artistic, traditions that suggest a movement towards this. Chapter one tackles the question of definition, linking mime within a wider physical theatre phenomenon. Chapter two looks at the importance of mime training for contemporary performance. This requires a focus on selected theatre practitioners who have significantly advanced the development of mime training and performance during the twentieth century. Chapter three examines the issue of silence in mime and questions a potential liberation of the word and language in contemporary performance and consequently how this affects the role of the performer, particularly in South Africa. Chapter four investigates the figure of the theatrical clown and how this late twentieth century development is playing an increasingly important role in contemporary performance. Chapter five then wraps up part one by pulling the preceding chapters together and thereby providing a working conceptualisation of the performer-creator, locating it within an overall appreciation of contemporary mime. Part two then tests the notion of the performer-creator by focussing on a case study through the investigation of Andrew Buckland to develop this idea. Andrew Buckland, and his work under the ethos of Mouthpeace from 1988-2000, provides a clear and unique example of this movement in contemporary South African performance. Trained as an actor and in classical illusion-based mime technique, as well as many dance forms such as ballet, contemporary and jazz, he has virtually single-handedly created and shaped a particular performance trend that is in line with contemporary international trends but retains a distinctive South African flavour. There is no space to attempt a definitive or exhaustive examination of his works, and nor is the intent to do so; rather, the aim is to draw from his work their essences that reveal his development as an artist: as both a creator and a performer.
- Full Text:
- Date Issued: 2002
- Authors: Murray, Robert Ian
- Date: 2002
- Subjects: Buckland, Andrew , Mime , Mimes -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2158 , http://hdl.handle.net/10962/d1007720
- Description: Part one of this thesis investigates the conceptualisation of the performer-creator and its relevance in late twentieth century physical performance by examining some of the theoretical, but mainly artistic, traditions that suggest a movement towards this. Chapter one tackles the question of definition, linking mime within a wider physical theatre phenomenon. Chapter two looks at the importance of mime training for contemporary performance. This requires a focus on selected theatre practitioners who have significantly advanced the development of mime training and performance during the twentieth century. Chapter three examines the issue of silence in mime and questions a potential liberation of the word and language in contemporary performance and consequently how this affects the role of the performer, particularly in South Africa. Chapter four investigates the figure of the theatrical clown and how this late twentieth century development is playing an increasingly important role in contemporary performance. Chapter five then wraps up part one by pulling the preceding chapters together and thereby providing a working conceptualisation of the performer-creator, locating it within an overall appreciation of contemporary mime. Part two then tests the notion of the performer-creator by focussing on a case study through the investigation of Andrew Buckland to develop this idea. Andrew Buckland, and his work under the ethos of Mouthpeace from 1988-2000, provides a clear and unique example of this movement in contemporary South African performance. Trained as an actor and in classical illusion-based mime technique, as well as many dance forms such as ballet, contemporary and jazz, he has virtually single-handedly created and shaped a particular performance trend that is in line with contemporary international trends but retains a distinctive South African flavour. There is no space to attempt a definitive or exhaustive examination of his works, and nor is the intent to do so; rather, the aim is to draw from his work their essences that reveal his development as an artist: as both a creator and a performer.
- Full Text:
- Date Issued: 2002
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