Electrochemical and photophysical characterization of non-peripherally-octaalkyl substituted dichlorotin (IV) phthalocyanine and tetrabenzotriazaporphyrin compounds
- Khene, Samson M, Cammidge, Andrew N, Cook, Michael J, Nyokong, Tebello
- Authors: Khene, Samson M , Cammidge, Andrew N , Cook, Michael J , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271216 , vital:54522 , xlink:href="https://doi.org/10.1142/S1088424607000886"
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (3a), octahexyltetrabenzo-5,10,15- triazaporphyrinato dichlorotin(IV) (3b) and octadecylphthalocyaninato dichlorotin(IV) (3c) were synthesized and their photophysical and electrochemical behavior studied. Complex 3b, containing a CH group in place of one of the aza nitrogen atoms of the phthalocyanine core, shows a split Q-band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (3a and 3c). In contrast, 3b shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in tetrahydrofuran than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring-based redox processes.
- Full Text:
- Date Issued: 2007
- Authors: Khene, Samson M , Cammidge, Andrew N , Cook, Michael J , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271216 , vital:54522 , xlink:href="https://doi.org/10.1142/S1088424607000886"
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (3a), octahexyltetrabenzo-5,10,15- triazaporphyrinato dichlorotin(IV) (3b) and octadecylphthalocyaninato dichlorotin(IV) (3c) were synthesized and their photophysical and electrochemical behavior studied. Complex 3b, containing a CH group in place of one of the aza nitrogen atoms of the phthalocyanine core, shows a split Q-band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (3a and 3c). In contrast, 3b shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in tetrahydrofuran than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring-based redox processes.
- Full Text:
- Date Issued: 2007
Reflecting on the 2007 World Environmental Education Congress
- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183047 , vital:43907 , xlink:href="https://doi.org/10.1177/097340820700100207"
- Description: What motivates more than 800 people from 101 countries around the world to meet at a World Environmental Education Congress? And how does one make the most of such an incredible gathering of people, cultures, thoughts and minds? What did people learn and was it worthwhile? These are just some of the questions that have been chasing through my mind in the weeks following the fourth World Environmental Education Congress held in Durban, South Africa, in July 2007. This short paper shares some preliminary reflections on the 2007 WEEC event, noting that in-depth analyses will only become possible as time passes.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183047 , vital:43907 , xlink:href="https://doi.org/10.1177/097340820700100207"
- Description: What motivates more than 800 people from 101 countries around the world to meet at a World Environmental Education Congress? And how does one make the most of such an incredible gathering of people, cultures, thoughts and minds? What did people learn and was it worthwhile? These are just some of the questions that have been chasing through my mind in the weeks following the fourth World Environmental Education Congress held in Durban, South Africa, in July 2007. This short paper shares some preliminary reflections on the 2007 WEEC event, noting that in-depth analyses will only become possible as time passes.
- Full Text:
- Date Issued: 2007
Rhodes University EE and Sustainability Unit
- Lotz-Sisitka, Heila, Schudel, Ingrid J
- Authors: Lotz-Sisitka, Heila , Schudel, Ingrid J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294423 , vital:57220 , xlink:href="https://doi.org/10.1177/097340820700100127"
- Description: In the early 1990s, in response to the emphasis laid on environment and development issues by the new South African Constitution, Rhodes University undertook several initiatives such as establishing the first Chair of Environmental Education (EE) in Africa. Another important initiative was the introduction of an open-entry participatory course for environmental educators. Owing to its flexible format and practice-based methodology, the course gained rapid popularity, necessitating the setting up of a Service Centre to help meet the increased demand. The Chair and the Service Centre have been providing a range of short courses in environment and sustainability education to professionals, and are today widely known as the Rhodes University Environmental Education and Sustainability Unit (RUEESU). The Unit offers PhD and Masters level programmes in EE, encourages meaningful research in key thematic areas, and is actively involved in publishing, and policy transformation. It also endeavours to define the role of Universities in enabling sustainability education.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila , Schudel, Ingrid J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294423 , vital:57220 , xlink:href="https://doi.org/10.1177/097340820700100127"
- Description: In the early 1990s, in response to the emphasis laid on environment and development issues by the new South African Constitution, Rhodes University undertook several initiatives such as establishing the first Chair of Environmental Education (EE) in Africa. Another important initiative was the introduction of an open-entry participatory course for environmental educators. Owing to its flexible format and practice-based methodology, the course gained rapid popularity, necessitating the setting up of a Service Centre to help meet the increased demand. The Chair and the Service Centre have been providing a range of short courses in environment and sustainability education to professionals, and are today widely known as the Rhodes University Environmental Education and Sustainability Unit (RUEESU). The Unit offers PhD and Masters level programmes in EE, encourages meaningful research in key thematic areas, and is actively involved in publishing, and policy transformation. It also endeavours to define the role of Universities in enabling sustainability education.
- Full Text:
- Date Issued: 2007
Think Piece : an opening dialogue with Think Pieces and feature articles on learning in a changing world in this journal
- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59602 , vital:27630 , https://www.ajol.info/index.php/sajee/article/view/122734
- Description: From Conclusion:This opening Think Piece invites you into such a dialogue, with this journal, its words and flows of meaning, and with the World Environmental Education Congress, its words and flows of meaning. Dialogue, as explained by Bohm, and as illustrated in the thought experiments in this paper, is a process of creatively and experimentally seeking out meaning and coherence through listening, and through deeper explorations of the tacit, implicate order. It is also a free process, where you as individual are invited to seek out the relations between your thoughts and the collective. Welcome to the process.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila
- Date: 2007
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59602 , vital:27630 , https://www.ajol.info/index.php/sajee/article/view/122734
- Description: From Conclusion:This opening Think Piece invites you into such a dialogue, with this journal, its words and flows of meaning, and with the World Environmental Education Congress, its words and flows of meaning. Dialogue, as explained by Bohm, and as illustrated in the thought experiments in this paper, is a process of creatively and experimentally seeking out meaning and coherence through listening, and through deeper explorations of the tacit, implicate order. It is also a free process, where you as individual are invited to seek out the relations between your thoughts and the collective. Welcome to the process.
- Full Text:
- Date Issued: 2007
Learning in a Changing World
- Lotz-Sisitka, Heila, O'Donoghue, Rob, Robottom, Ian
- Authors: Lotz-Sisitka, Heila , O'Donoghue, Rob , Robottom, Ian
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182679 , vital:43853 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122733 "
- Description: The year 2007 is a significant year for environmental education. It marks 30 years since the first internationally agreed principles of environmental education were developed at Tbilisi, commonly known as the Tbilisi Principles. It is also the year in which human beings apparently are finally ‘waking up’ to the fact that human-induced environmental change is causing impacts which are infinitely complex and difficult to resolve. This year, through various highly publicised and politicised events, people have begun to recognise that it is getting hot on planet Earth, and that the associated social, economic and environmental costs are profoundly disturbing. The Stern Review and the UN Intergovernmental Panel on Climate Change both firmly indicated that human-induced environmental change will threaten human economies and security in ways that are unprecedented in human history. Southern Africa, where this special edition of the EEASA Journal is being produced to coincide with the 25th anniversary of the existence of the Environmental Education Association of Southern Africa, and the hosting of the 4th World Environmental Education Congress, is one of the areas most vulnerable to the impacts of climate change. More than 70% of the people in southern Africa live in rural areas, and depend directly on natural resources for their livelihood and food security, making environment (and environmental education processes) a central concern in development discussions in the region. Patterns of global inequality are pronounced in the region, which has some of the poorest countries in the world. Out of its 25-year history, EEASA and its members, along with colleagues around the world, continue to seek ways of educating and empowering people to successfully participate in resolving environmental issues and create more sustainable and socially just living patterns. In drawing attention to our constant need to learn how to improve our understandings of environmental education and learning as the world around us changes, the World Environmental Education Congress organising committee chose to profile the question of ‘Learning in a Changing World’, by making this the theme of the Congress.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila , O'Donoghue, Rob , Robottom, Ian
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182679 , vital:43853 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122733 "
- Description: The year 2007 is a significant year for environmental education. It marks 30 years since the first internationally agreed principles of environmental education were developed at Tbilisi, commonly known as the Tbilisi Principles. It is also the year in which human beings apparently are finally ‘waking up’ to the fact that human-induced environmental change is causing impacts which are infinitely complex and difficult to resolve. This year, through various highly publicised and politicised events, people have begun to recognise that it is getting hot on planet Earth, and that the associated social, economic and environmental costs are profoundly disturbing. The Stern Review and the UN Intergovernmental Panel on Climate Change both firmly indicated that human-induced environmental change will threaten human economies and security in ways that are unprecedented in human history. Southern Africa, where this special edition of the EEASA Journal is being produced to coincide with the 25th anniversary of the existence of the Environmental Education Association of Southern Africa, and the hosting of the 4th World Environmental Education Congress, is one of the areas most vulnerable to the impacts of climate change. More than 70% of the people in southern Africa live in rural areas, and depend directly on natural resources for their livelihood and food security, making environment (and environmental education processes) a central concern in development discussions in the region. Patterns of global inequality are pronounced in the region, which has some of the poorest countries in the world. Out of its 25-year history, EEASA and its members, along with colleagues around the world, continue to seek ways of educating and empowering people to successfully participate in resolving environmental issues and create more sustainable and socially just living patterns. In drawing attention to our constant need to learn how to improve our understandings of environmental education and learning as the world around us changes, the World Environmental Education Congress organising committee chose to profile the question of ‘Learning in a Changing World’, by making this the theme of the Congress.
- Full Text:
- Date Issued: 2007
Exploring the practical adequacy of the normative framework guiding South Africa’s National Curriculum Statement
- Lotz-Sisitka, Heila, Schudel, Ingrid J
- Authors: Lotz-Sisitka, Heila , Schudel, Ingrid J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294386 , vital:57217 , xlink:href="https://doi.org/10.1080/13504620701284860"
- Description: This article examines the practical adequacy of the recent defining of a normative framework for the South African National Curriculum Statement that focuses on the relationship between human rights, social justice and a healthy environment. This politically framed and socially critical normative framework has developed in response to socio‐political and socio‐ecological histories in post‐apartheid curriculum transformation processes. The article critically considers the process of working with a normative framework in the defining of environmental education teaching and learning interactions, and seeks not only to explore the policy discourse critically, but also to explore what it is about the world that makes it work in different ways. Drawing on Sayer’s perspectives on the possibilities of enabling ‘situated universalism’ as a form of normative theory, and case‐based data from a teacher professional development programme in the Makana District (where the authors live and work), the article probes the relationship between the establishment of a ‘universalising’ normative framework to guide national curriculum, and situated engagements with this framework in/as democratic process. In this process it questions whether educators should adopt the ‘norms’ as presented by society and simply universalize and implement them as prescribed by curriculum statements, or whether educators should adopt the strategies of postmodernists and reduce normative frameworks to relations of power situated in particular contexts.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila , Schudel, Ingrid J
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/294386 , vital:57217 , xlink:href="https://doi.org/10.1080/13504620701284860"
- Description: This article examines the practical adequacy of the recent defining of a normative framework for the South African National Curriculum Statement that focuses on the relationship between human rights, social justice and a healthy environment. This politically framed and socially critical normative framework has developed in response to socio‐political and socio‐ecological histories in post‐apartheid curriculum transformation processes. The article critically considers the process of working with a normative framework in the defining of environmental education teaching and learning interactions, and seeks not only to explore the policy discourse critically, but also to explore what it is about the world that makes it work in different ways. Drawing on Sayer’s perspectives on the possibilities of enabling ‘situated universalism’ as a form of normative theory, and case‐based data from a teacher professional development programme in the Makana District (where the authors live and work), the article probes the relationship between the establishment of a ‘universalising’ normative framework to guide national curriculum, and situated engagements with this framework in/as democratic process. In this process it questions whether educators should adopt the ‘norms’ as presented by society and simply universalize and implement them as prescribed by curriculum statements, or whether educators should adopt the strategies of postmodernists and reduce normative frameworks to relations of power situated in particular contexts.
- Full Text:
- Date Issued: 2007
Translation processes in the design of an education for sustainable development innovations course for universities in Africa
- Lotz-Sisitka, Heila, Lupele, Justin, Ogbuigwe, Akpezi
- Authors: Lotz-Sisitka, Heila , Lupele, Justin , Ogbuigwe, Akpezi
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127213 , vital:35978 , https://10.1080/02607470701259440
- Description: This paper traces the translation processes associated with the mobilization of resources and human agency in the development of a United Nations Environment Programme (UNEP) Education for Sustainable Development (ESD) Innovations Course for universities in Africa. University teachers are often neglected in teacher education initiatives. There are few formal professional development opportunities available for university teachers given the traditionally established hierarchy in the higher education sector as university teachers are normally the ones offering professional development to others. The paper explores how a participatory, deliberative translation process has served to provide professional development and professional exchange opportunities for university teachers which are non‐traditional and responsive to diversity, history, context and risk. The emergence of the modern African university is essentially a post‐independence (post‐1960s) phenomenon, with a few earlier African universities being colonially structured, controlled and inspired. Through a short historical overview, we introduce the African university landscape and some of its contemporary contextual and educational challenges. We then describe the process of deliberation that took place amongst university teachers from 23 African countries to initiate and establish the ESD Innovations Course. The paper concludes by arguing for open and participatory approaches in ESD teacher education course design, if we are to support university teachers (including teacher educators) to engage in mainstreaming environment and sustainability questions in higher education. The paper draws on the translation model provided by Latour in his actor network theory to describe and explain the deliberative translation process in the UNEP ESD Innovations Course. In doing this, it illuminates the possibilities of such a deliberative translation process for university teacher education. It also points to limitations encountered in applying this framework to this analysis, opening new vantage points for research of this nature in teacher education.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila , Lupele, Justin , Ogbuigwe, Akpezi
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127213 , vital:35978 , https://10.1080/02607470701259440
- Description: This paper traces the translation processes associated with the mobilization of resources and human agency in the development of a United Nations Environment Programme (UNEP) Education for Sustainable Development (ESD) Innovations Course for universities in Africa. University teachers are often neglected in teacher education initiatives. There are few formal professional development opportunities available for university teachers given the traditionally established hierarchy in the higher education sector as university teachers are normally the ones offering professional development to others. The paper explores how a participatory, deliberative translation process has served to provide professional development and professional exchange opportunities for university teachers which are non‐traditional and responsive to diversity, history, context and risk. The emergence of the modern African university is essentially a post‐independence (post‐1960s) phenomenon, with a few earlier African universities being colonially structured, controlled and inspired. Through a short historical overview, we introduce the African university landscape and some of its contemporary contextual and educational challenges. We then describe the process of deliberation that took place amongst university teachers from 23 African countries to initiate and establish the ESD Innovations Course. The paper concludes by arguing for open and participatory approaches in ESD teacher education course design, if we are to support university teachers (including teacher educators) to engage in mainstreaming environment and sustainability questions in higher education. The paper draws on the translation model provided by Latour in his actor network theory to describe and explain the deliberative translation process in the UNEP ESD Innovations Course. In doing this, it illuminates the possibilities of such a deliberative translation process for university teacher education. It also points to limitations encountered in applying this framework to this analysis, opening new vantage points for research of this nature in teacher education.
- Full Text:
- Date Issued: 2007
Editorial, 2007
- Lotz-Sisitka, Heila, O’Donoghue, Rob, Robottom, Ian
- Authors: Lotz-Sisitka, Heila , O’Donoghue, Rob , Robottom, Ian
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67345 , vital:29078 , https://www.ajol.info/index.php/sajee/article/view/122733
- Description: publisher version , The year 2007 is a significant year for environmental education. It marks 30 years since the first internationally agreed principles of environmental education were developed at Tbilisi, commonly known as the Tbilisi Principles. It is also the year in which human beings apparently are finally ‘waking up’ to the fact that human-induced environmental change is causing impacts which are infinitely complex and difficult to resolve. This year, through various highly publicised and politicised events, people have begun to recognise that it is getting hot on planet Earth, and that the associated social, economic and environmental costs are profoundly disturbing. The Stern Review and the UN Intergovernmental Panel on Climate Change both firmly indicated that human-induced environmental change will threaten human economies and security in ways that are unprecedented in human history.
- Full Text:
- Date Issued: 2007
- Authors: Lotz-Sisitka, Heila , O’Donoghue, Rob , Robottom, Ian
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67345 , vital:29078 , https://www.ajol.info/index.php/sajee/article/view/122733
- Description: publisher version , The year 2007 is a significant year for environmental education. It marks 30 years since the first internationally agreed principles of environmental education were developed at Tbilisi, commonly known as the Tbilisi Principles. It is also the year in which human beings apparently are finally ‘waking up’ to the fact that human-induced environmental change is causing impacts which are infinitely complex and difficult to resolve. This year, through various highly publicised and politicised events, people have begun to recognise that it is getting hot on planet Earth, and that the associated social, economic and environmental costs are profoundly disturbing. The Stern Review and the UN Intergovernmental Panel on Climate Change both firmly indicated that human-induced environmental change will threaten human economies and security in ways that are unprecedented in human history.
- Full Text:
- Date Issued: 2007
Written medicines information for South African HIV/AIDS patients: does it enhance understanding of co-trimoxazole therapy?
- Mansoor, Leila E, Dowse, Roslind
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156860 , vital:40059 , https://0-doi.org.wam.seals.ac.za/10.1093/her/cyl039
- Description: Written information to promote patient education is being increasingly recognized as an integral part of quality health care. The main objective of this study was to evaluate the effect of distributing a patient information leaflet (PIL) on knowledge acquisition and recall. Two different PILs were designed for co-trimoxazole tablets: a simple, shorter PIL that incorporated pictograms and text and a text-only PIL that was longer and more complex. Human immunodeficiency virus-positive participants on chronic co-trimoxazole therapy were enrolled from five local primary health care clinics in Grahamstown, South Africa, and were randomly allocated to a Control Group (no PIL), Group A (text-only PIL) or Group B (simple PIL with pictograms).
- Full Text:
- Date Issued: 2007
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156860 , vital:40059 , https://0-doi.org.wam.seals.ac.za/10.1093/her/cyl039
- Description: Written information to promote patient education is being increasingly recognized as an integral part of quality health care. The main objective of this study was to evaluate the effect of distributing a patient information leaflet (PIL) on knowledge acquisition and recall. Two different PILs were designed for co-trimoxazole tablets: a simple, shorter PIL that incorporated pictograms and text and a text-only PIL that was longer and more complex. Human immunodeficiency virus-positive participants on chronic co-trimoxazole therapy were enrolled from five local primary health care clinics in Grahamstown, South Africa, and were randomly allocated to a Control Group (no PIL), Group A (text-only PIL) or Group B (simple PIL with pictograms).
- Full Text:
- Date Issued: 2007
Photocatalysis of 4-nitrophenol using zinc phthalocyanine complexes
- Marais, Eloïse, Klein, Rosalyn, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloïse , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007
- Authors: Marais, Eloïse , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007
JM Coetzee and the ethics of reading:
- Authors: Marais, Mike
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144253 , vital:38325 , https://www.jstor.org/stable/pdf/26286886.pdf
- Description: One of Derek Attridge's principal concerns in J. M. Coetzee and the Ethics of Reading is the relationship that is established with alterity in the writing and reading of literary works. As is evident from the fact that some of the chapters in the book date back more than a decade, this is an abiding concern. Indeed, The Singularity of Literature, which also appeared in 2004, theorizes this relationship at great length. In it, Attridge describes the literary text as the emanation of an act of creation, that is, that mysterious experience in which the writer, who is located in culture's familiar modes of understanding, encounters something strange (in that it does not yet exist within the horizon that culture provides for thinking and feeling) and is required to resist the mind's tendency to reduce novelty by understanding it in terms of the familiar.
- Full Text:
- Date Issued: 2007
- Authors: Marais, Mike
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144253 , vital:38325 , https://www.jstor.org/stable/pdf/26286886.pdf
- Description: One of Derek Attridge's principal concerns in J. M. Coetzee and the Ethics of Reading is the relationship that is established with alterity in the writing and reading of literary works. As is evident from the fact that some of the chapters in the book date back more than a decade, this is an abiding concern. Indeed, The Singularity of Literature, which also appeared in 2004, theorizes this relationship at great length. In it, Attridge describes the literary text as the emanation of an act of creation, that is, that mysterious experience in which the writer, who is located in culture's familiar modes of understanding, encounters something strange (in that it does not yet exist within the horizon that culture provides for thinking and feeling) and is required to resist the mind's tendency to reduce novelty by understanding it in terms of the familiar.
- Full Text:
- Date Issued: 2007
Surface chemistry and electrocatalytic behaviour of tetra-carboxy substituted iron, cobalt and manganese phthalocyanine monolayers on gold electrode
- Mashazi, Philani N, Westbroek, Philippe, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Mashazi, Philani N , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268806 , vital:54233 , xlink:href="https://doi.org/10.1016/j.electacta.2007.08.044"
- Description: Surface chemistry and electrocatalytic properties of self-assembled monolayers of metal tetra-carboxylic acid phthalocyanine complexes with cobalt (Co), iron (Fe) and manganese (Mn) as central metal ions have been studied. These phthalocyanine molecules are immobilized on gold electrode via the coupling reaction between the ring substituents and pre-formed mercaptoethanol self-assembled monolayer (Au-ME SAM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed chemisorption of mercaptoethanol via sulfur group on gold electrode and also coupling reaction between phthalocyanines and Au-ME SAM. Electrochemical parameters of the immobilized molecules show that these molecules are densely packed with a perpendicular orientation. The potential applications of the gold modified electrodes were investigated towards L-cysteine detection and the analysis at phthalocyanine SAMs. Cobalt and iron tetra-carboxylic acid phthalocyanine monolayers showed good oxidation peak for L-cysteine at potentials where metal oxidation (MIII/MII) takes place and this metal oxidation mediates the catalytic oxidation of L-cysteine. Manganese tetra-carboxylic acid phthalocyanine monolayer also exhibited a good catalytic oxidation peak towards L-cysteine at potentials where MnIV/MnIII redox peak occurs and this redox peak mediates L-cysteine oxidation. The analysis of cysteine at phthalocyanine monolayers displayed good analytical parameters with good detection limits of the orders of 10−7 mol L−1 and good linearity for a studied concentration range up to 60 μmol L−1.
- Full Text:
- Date Issued: 2007
- Authors: Mashazi, Philani N , Westbroek, Philippe , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268806 , vital:54233 , xlink:href="https://doi.org/10.1016/j.electacta.2007.08.044"
- Description: Surface chemistry and electrocatalytic properties of self-assembled monolayers of metal tetra-carboxylic acid phthalocyanine complexes with cobalt (Co), iron (Fe) and manganese (Mn) as central metal ions have been studied. These phthalocyanine molecules are immobilized on gold electrode via the coupling reaction between the ring substituents and pre-formed mercaptoethanol self-assembled monolayer (Au-ME SAM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed chemisorption of mercaptoethanol via sulfur group on gold electrode and also coupling reaction between phthalocyanines and Au-ME SAM. Electrochemical parameters of the immobilized molecules show that these molecules are densely packed with a perpendicular orientation. The potential applications of the gold modified electrodes were investigated towards L-cysteine detection and the analysis at phthalocyanine SAMs. Cobalt and iron tetra-carboxylic acid phthalocyanine monolayers showed good oxidation peak for L-cysteine at potentials where metal oxidation (MIII/MII) takes place and this metal oxidation mediates the catalytic oxidation of L-cysteine. Manganese tetra-carboxylic acid phthalocyanine monolayer also exhibited a good catalytic oxidation peak towards L-cysteine at potentials where MnIV/MnIII redox peak occurs and this redox peak mediates L-cysteine oxidation. The analysis of cysteine at phthalocyanine monolayers displayed good analytical parameters with good detection limits of the orders of 10−7 mol L−1 and good linearity for a studied concentration range up to 60 μmol L−1.
- Full Text:
- Date Issued: 2007
Electroanalysis of thiocyanate using a novel glassy carbon electrode modified by aryl radicals and cobalt tetracarboxyphthalocyanine
- Matemadombo, Fungisai, Westbroek, Philippe, Nyokong, Tebello
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268750 , vital:54228 , xlink:href="https://doi.org/10.1016/j.electacta.2007.06.064"
- Description: Electrochemical grafting of 4-nitrobenzenediazonium tetrafluoroborate onto a glassy carbon electrode (GCE) results in the formation of a nitrophenyl radical, which reacts with the surface to form a covalent bond (grafting) and results in a nitrophenyl modified electrode. The nitro group is electrochemically reduced to a NH2 group. Cobalt tetracarboxyphthalocyanine (CoTCPc) complex is then attached to the NH2 group using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as coupling agents. The new CoTCPc modified electrode was characterized using cyclic voltammetry and then employed for the catalytic oxidation of thiocyanate.
- Full Text:
- Date Issued: 2007
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268750 , vital:54228 , xlink:href="https://doi.org/10.1016/j.electacta.2007.06.064"
- Description: Electrochemical grafting of 4-nitrobenzenediazonium tetrafluoroborate onto a glassy carbon electrode (GCE) results in the formation of a nitrophenyl radical, which reacts with the surface to form a covalent bond (grafting) and results in a nitrophenyl modified electrode. The nitro group is electrochemically reduced to a NH2 group. Cobalt tetracarboxyphthalocyanine (CoTCPc) complex is then attached to the NH2 group using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as coupling agents. The new CoTCPc modified electrode was characterized using cyclic voltammetry and then employed for the catalytic oxidation of thiocyanate.
- Full Text:
- Date Issued: 2007
Immobilization of tetra-amine substituted metallophthalocyanines at gold surfaces modified with mercaptopropionic acid or DTSP-SAMs
- Matemadombo, Fungisai, Westbroek, Philippe, Nyokong, Tebello, Ozoemena, Kenneth, De Clerck, Karen, Kiekens, Paul
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello , Ozoemena, Kenneth , De Clerck, Karen , Kiekens, Paul
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283924 , vital:56003 , xlink:href="https://doi.org/10.1016/j.electacta.2006.08.027"
- Description: This paper shows that amine substituted cobalt phthalocyanine (CoTAPc) can be deposited on gold surfaces by using an interconnecting layer of a self-assembled monolayer (SAM) of mercaptopropionic acid or Lomant's reagent (dithiobis(N-succinimidyl propionate) (DTSP)). In both cases the new bond formed is obtained by the creation of an amide. The layers were characterized by electrochemistry and showed high coverage fractions (near 100%). Reductive and oxidative desorption of the SAMs limit the useful potential window from −0.6 to +0.5 V versus Ag|AgCl. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. The amount of CoTAPc molecules deposited (obtained from the Co central metal ion activity in nitrogen purged solutions) revealed that the CoTAPc molecules are bonded in a perpendicular manner at the surface. Taking into account a surface of 200 Å2 for a flatly bonded MPc, this should result in a four times less amount of deposited CoTAPc compared to the experimental value obtained. Both methods showed good results and promising long-term stability and will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Date Issued: 2007
- Authors: Matemadombo, Fungisai , Westbroek, Philippe , Nyokong, Tebello , Ozoemena, Kenneth , De Clerck, Karen , Kiekens, Paul
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283924 , vital:56003 , xlink:href="https://doi.org/10.1016/j.electacta.2006.08.027"
- Description: This paper shows that amine substituted cobalt phthalocyanine (CoTAPc) can be deposited on gold surfaces by using an interconnecting layer of a self-assembled monolayer (SAM) of mercaptopropionic acid or Lomant's reagent (dithiobis(N-succinimidyl propionate) (DTSP)). In both cases the new bond formed is obtained by the creation of an amide. The layers were characterized by electrochemistry and showed high coverage fractions (near 100%). Reductive and oxidative desorption of the SAMs limit the useful potential window from −0.6 to +0.5 V versus Ag|AgCl. The SAM-CoTAPc layers show electrocatalytic activities towards oxygen reduction through the Co(I) central metal ion. The amount of CoTAPc molecules deposited (obtained from the Co central metal ion activity in nitrogen purged solutions) revealed that the CoTAPc molecules are bonded in a perpendicular manner at the surface. Taking into account a surface of 200 Å2 for a flatly bonded MPc, this should result in a four times less amount of deposited CoTAPc compared to the experimental value obtained. Both methods showed good results and promising long-term stability and will be interesting tools for further research in surface modification and sensor development.
- Full Text:
- Date Issued: 2007
Characterization of self-assembled monolayers of iron and cobalt octaalkylthiosubstituted phthalocyanines and their use in nitrite electrocatalytic oxidation
- Matemadombo, Fungisai, Nyokong, Tebello
- Authors: Matemadombo, Fungisai , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271182 , vital:54519 , xlink:href="https://doi.org/10.1016/j.electacta.2007.05.002"
- Description: Cobalt and iron phenylthiosubstituted phthalocyanines have been deposited on Au electrode surfaces through the self-assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric and impedance techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of nitrite. The electrocatalytic parameters of the cobalt and iron phenylthiosubstituted phthalocyanines deposited on Au electrodes in nitrite solution were studied. Nitrite overpotentials which are lower than ever reported were obtained in this work for the iron phenylthiosubstituted phthalocyanines with very high stability.
- Full Text:
- Date Issued: 2007
- Authors: Matemadombo, Fungisai , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271182 , vital:54519 , xlink:href="https://doi.org/10.1016/j.electacta.2007.05.002"
- Description: Cobalt and iron phenylthiosubstituted phthalocyanines have been deposited on Au electrode surfaces through the self-assembled monolayer (SAM) technique. The so formed layers were studied using voltammetric and impedance techniques. These SAMs blocked a number of Faradic processes and electrocatalyzed the oxidation of nitrite. The electrocatalytic parameters of the cobalt and iron phenylthiosubstituted phthalocyanines deposited on Au electrodes in nitrite solution were studied. Nitrite overpotentials which are lower than ever reported were obtained in this work for the iron phenylthiosubstituted phthalocyanines with very high stability.
- Full Text:
- Date Issued: 2007
Synthesis and electrochemical properties of purple manganese (III) and red titanium (IV) phthalocyanine complexes octa-substituted at non-peripheral positions with pentylthio groups
- Mbambisa, Gcineka, Tau, Prudence, Antunes, Edith M, Nyokong, Tebello
- Authors: Mbambisa, Gcineka , Tau, Prudence , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271252 , vital:54525 , xlink:href="https://doi.org/10.1016/j.poly.2007.08.007"
- Description: The synthesis and electrochemical characterisation of octapentylthiophthalocyaninato manganese (III) acetate (4) and octapentylthiophthalocyaninato titanium (IV) oxide (5) complexes are reported. The complexes have an unusual purple (4) and red (5) colouration since the Q-band is shifted to the near infrared region with Q-band maxima at 893 nm and 808 nm in dichloromethane for 4 and 5, respectively. The structures of the complexes were confirmed by elemental analysis and interpretation of their spectroscopic data, including 2D NMR. The cyclic voltammetry (CV) of the Mn complex (4) showed four quasi reversible couples. The reduction processes are attributed to MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 and the oxidation processes to MnIVPc−2/MnIIIPc−2 and MnIVPc−1/MnIVPc−2. The processes were confirmed by spectroelectrochemistry. A well-defined spectrum of the rare MnIVPc−2 species is reported. The CV of the Ti complex (5) showed two well-resolved reduction processes due to TiIVPc−2/TiIIIPc−2 and TiIIIPc−2/TiIIPc−2. However, oxidation processes of the complex revealed adsorption behaviour and resulted in decomposition on electrolysis using spectroelectrochemistry.
- Full Text:
- Date Issued: 2007
- Authors: Mbambisa, Gcineka , Tau, Prudence , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271252 , vital:54525 , xlink:href="https://doi.org/10.1016/j.poly.2007.08.007"
- Description: The synthesis and electrochemical characterisation of octapentylthiophthalocyaninato manganese (III) acetate (4) and octapentylthiophthalocyaninato titanium (IV) oxide (5) complexes are reported. The complexes have an unusual purple (4) and red (5) colouration since the Q-band is shifted to the near infrared region with Q-band maxima at 893 nm and 808 nm in dichloromethane for 4 and 5, respectively. The structures of the complexes were confirmed by elemental analysis and interpretation of their spectroscopic data, including 2D NMR. The cyclic voltammetry (CV) of the Mn complex (4) showed four quasi reversible couples. The reduction processes are attributed to MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 and the oxidation processes to MnIVPc−2/MnIIIPc−2 and MnIVPc−1/MnIVPc−2. The processes were confirmed by spectroelectrochemistry. A well-defined spectrum of the rare MnIVPc−2 species is reported. The CV of the Ti complex (5) showed two well-resolved reduction processes due to TiIVPc−2/TiIIIPc−2 and TiIIIPc−2/TiIIPc−2. However, oxidation processes of the complex revealed adsorption behaviour and resulted in decomposition on electrolysis using spectroelectrochemistry.
- Full Text:
- Date Issued: 2007
Compositionally diverse magmas erupted close together in space and time within a Karoo flood basalt crater complex:
- McClintock, Murray, Marsh, Julian S, White, James D L
- Authors: McClintock, Murray , Marsh, Julian S , White, James D L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144966 , vital:38396 , https://doi.org/10.1007/s00445-007-0178-6
- Description: Geochemical data and mapping from a Karoo flood basalt crater complex reveals new information about the ascent and eruption of magma batches during the earliest phases of flood basalt volcanism. Flood basalt eruptions at Sterkspruit, South Africa began with emplacement of thin lava flows before abruptly switching to explosive phreatomagmatic and magmatic activity that formed a nest of craters, spatter and tuff rings and cones that collectively comprise a crater complex >40 km2 filled by 9–18 km3 of volcaniclastic debris.
- Full Text:
- Date Issued: 2008
- Authors: McClintock, Murray , Marsh, Julian S , White, James D L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144966 , vital:38396 , https://doi.org/10.1007/s00445-007-0178-6
- Description: Geochemical data and mapping from a Karoo flood basalt crater complex reveals new information about the ascent and eruption of magma batches during the earliest phases of flood basalt volcanism. Flood basalt eruptions at Sterkspruit, South Africa began with emplacement of thin lava flows before abruptly switching to explosive phreatomagmatic and magmatic activity that formed a nest of craters, spatter and tuff rings and cones that collectively comprise a crater complex >40 km2 filled by 9–18 km3 of volcaniclastic debris.
- Full Text:
- Date Issued: 2008
Submerged membrane bioreactor and secondary digestion for the treatment of wine distillery wastewater: Part I: Raw wine distillery wastewater digestion
- Melamane, Xolisa L, Tandlich, Roman, Burgess, Jo E
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76139 , vital:30511 , https://www.prt-parlar.de/download_feb_2007/
- Description: A combination of a submerged membrane bioreactor (SMBR) and a secondary digester was tested for the treatment of wine distillery wastewater (WDW). The experimental system, consisting of four individual reactors, was tested during a 30-days study. Buffering of pH was achieved by mixing the feed stream of the system with 1000 mg/l of CaCO3 and K2HPO4 for the initial 10 days of the bioreactor system operation, and with 8000 mg/l of CaCO3 and 4000 mg/l of K2HPO4 for the remainder of the study. Buffering proved to be significant for optimum performance of the system in removal of soluble chemical oxygen demand (CODS), and volatile fatty acids (VFAs). Different batches of WDW used for feeding the reactor had variable compositions with respect to concentrations of nitrates, ammonium and the total concentration of phenolic compounds. Am-monium accumulated in the secondary digester after 14 days of treatment system operation, indicating the time required for the establishment of anaerobic conditions in the system. An additional step would be required for removal of phosphates from the effluent of the bioreactor, e.g., reverse osmosis, if the effluent is to be reused in production or other applications.
- Full Text:
- Date Issued: 2007
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76139 , vital:30511 , https://www.prt-parlar.de/download_feb_2007/
- Description: A combination of a submerged membrane bioreactor (SMBR) and a secondary digester was tested for the treatment of wine distillery wastewater (WDW). The experimental system, consisting of four individual reactors, was tested during a 30-days study. Buffering of pH was achieved by mixing the feed stream of the system with 1000 mg/l of CaCO3 and K2HPO4 for the initial 10 days of the bioreactor system operation, and with 8000 mg/l of CaCO3 and 4000 mg/l of K2HPO4 for the remainder of the study. Buffering proved to be significant for optimum performance of the system in removal of soluble chemical oxygen demand (CODS), and volatile fatty acids (VFAs). Different batches of WDW used for feeding the reactor had variable compositions with respect to concentrations of nitrates, ammonium and the total concentration of phenolic compounds. Am-monium accumulated in the secondary digester after 14 days of treatment system operation, indicating the time required for the establishment of anaerobic conditions in the system. An additional step would be required for removal of phosphates from the effluent of the bioreactor, e.g., reverse osmosis, if the effluent is to be reused in production or other applications.
- Full Text:
- Date Issued: 2007
Anaerobic digestion of fungally pre-treated wine distillery wastewater
- Melamane, Xolisa L, Tandlich, Roman, Burgess, Jo E
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71740 , vital:29932 , https://doi.org/10.5897/AJB2007.000-2305
- Description: The combination of fungal pre-treatment with Trametes pubescens and anaerobic digestion were tested for the removal of chemical oxygen demand (COD) and phenolic compounds from wine distillery wastewater. The COD removal efficiency after fungal pre-treatment reached 53.3%. During digestion, pH buffering was achieved using CaCO3 and K2HPO4. This provided a stable environment inside digester for efficient and time-independent COD removal. The total COD removal efficiency reached 99.5%, and the system proved able to eliminate shock COD loads, as indicated by the concentrations of sludge and volatile fatty acids. Complex changes of phenolic compounds are suspected in anaerobic digestion system, and are investigated further.
- Full Text:
- Date Issued: 2007
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71740 , vital:29932 , https://doi.org/10.5897/AJB2007.000-2305
- Description: The combination of fungal pre-treatment with Trametes pubescens and anaerobic digestion were tested for the removal of chemical oxygen demand (COD) and phenolic compounds from wine distillery wastewater. The COD removal efficiency after fungal pre-treatment reached 53.3%. During digestion, pH buffering was achieved using CaCO3 and K2HPO4. This provided a stable environment inside digester for efficient and time-independent COD removal. The total COD removal efficiency reached 99.5%, and the system proved able to eliminate shock COD loads, as indicated by the concentrations of sludge and volatile fatty acids. Complex changes of phenolic compounds are suspected in anaerobic digestion system, and are investigated further.
- Full Text:
- Date Issued: 2007
Submerged membrane bioreactor and secondary digestion in the treatment of wine distillery waste: Part II: the effect of fungal pre-treatment on wine distillery wastewater digestion
- Melamane, Xolisa L, Strong, Peter James, Tandlich, Roman, Burgess, Jo E
- Authors: Melamane, Xolisa L , Strong, Peter James , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76150 , vital:30514 , https://www.prt-parlar.de/download_feb_2007/
- Description: The effect of fungal pre-treatment using Trametes pubescens on the anaerobic digestion ultrafiltration treatment of wine distillery wastewater (WDW) was studied. The downstream biological treatment system, consisting of four individual reactors, was operated for 30 days. pH buffering was achieved by mixing the pre-treated system feed with CaCO3 and K2HPO4; this proved significant for optimum performance of the system in removal of soluble chemical oxygen demand (CODS). The experimental system was shown to eliminate an average of 86 (± 4) % of CODS present in the pre-treated WDW. Treatment in a submerged membrane bioreactor (SMBR) and subsequent secondary digester, together with pH buffering using CaCO3 and K2HPO4, led to the stabilisation of CODS removal. The residual CODS levels in the final effluent were approximately 400 mg/l, significantly lower than the concentrations observed when treating raw WDW, indicating that fungal pre-treatment might have provided additional nutrients for removal of recalcitrant components of the wastewater. The resulting effluent of the system is rich in nitrates and phosphates. Together with the residual organic content it might be used as a fertiliser. Alternatively, if water management of the wine distillery is an issue, a membrane process, such as reverse osmosis or nanofiltration could be applied to bring the parameters of the water to meet the technological needs.
- Full Text:
- Date Issued: 2007
- Authors: Melamane, Xolisa L , Strong, Peter James , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76150 , vital:30514 , https://www.prt-parlar.de/download_feb_2007/
- Description: The effect of fungal pre-treatment using Trametes pubescens on the anaerobic digestion ultrafiltration treatment of wine distillery wastewater (WDW) was studied. The downstream biological treatment system, consisting of four individual reactors, was operated for 30 days. pH buffering was achieved by mixing the pre-treated system feed with CaCO3 and K2HPO4; this proved significant for optimum performance of the system in removal of soluble chemical oxygen demand (CODS). The experimental system was shown to eliminate an average of 86 (± 4) % of CODS present in the pre-treated WDW. Treatment in a submerged membrane bioreactor (SMBR) and subsequent secondary digester, together with pH buffering using CaCO3 and K2HPO4, led to the stabilisation of CODS removal. The residual CODS levels in the final effluent were approximately 400 mg/l, significantly lower than the concentrations observed when treating raw WDW, indicating that fungal pre-treatment might have provided additional nutrients for removal of recalcitrant components of the wastewater. The resulting effluent of the system is rich in nitrates and phosphates. Together with the residual organic content it might be used as a fertiliser. Alternatively, if water management of the wine distillery is an issue, a membrane process, such as reverse osmosis or nanofiltration could be applied to bring the parameters of the water to meet the technological needs.
- Full Text:
- Date Issued: 2007