Biphenyl sorption to different soil clay minerals
- Tandlich, Roman, Baláž, Štefan
- Authors: Tandlich, Roman , Baláž, Štefan
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76869 , vital:30632 , https://doi.org/10.5897/AJAR10.1012
- Description: Only limited information is available in the literature on the role of soil mineral surfaces in the sorption of hydrophobic organic pollutants. This knowledge gap is addressed through the assessment of biphenyl sorption to kaolinite, illite and bentonite; using the batch equilibration technique with incubations lasting 6 or 21 days at 28 ± 2°C in the dark [RT1]. Sorption of biphenyl onto kaolinite followed the Freundlich sorption isotherm, whereas linear sorption isotherms were observed on illite and bentonite [RT2]. The biphenyl sorption partition coefficient on kaolinite ranged from 0.1 to 9.1 cm3.g-1 after 6 days and no sorption was observed after 21 days. This could have been caused by a completely reversible sorption or a loss of binding capacity after 21 days [RT3]. The respective values of the biphenyl sorption partition coefficient on illite and bentonite ranged from 20.3 ± 0.3 to 120 ± 8 cm3.g-1.Sorption equilibrium on the internal clay surfaces was reached after 6 days, as indicated by the sorption data for illite and bentonite [RT4]. Access of biphenyl molecules to the internal clay surfaces is a function of the ionic strength of soil solution and the soil organic matter is the dominant site for biphenyl sorption after 6 to 21 days.
- Full Text:
- Date Issued: 2011
- Authors: Tandlich, Roman , Baláž, Štefan
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76869 , vital:30632 , https://doi.org/10.5897/AJAR10.1012
- Description: Only limited information is available in the literature on the role of soil mineral surfaces in the sorption of hydrophobic organic pollutants. This knowledge gap is addressed through the assessment of biphenyl sorption to kaolinite, illite and bentonite; using the batch equilibration technique with incubations lasting 6 or 21 days at 28 ± 2°C in the dark [RT1]. Sorption of biphenyl onto kaolinite followed the Freundlich sorption isotherm, whereas linear sorption isotherms were observed on illite and bentonite [RT2]. The biphenyl sorption partition coefficient on kaolinite ranged from 0.1 to 9.1 cm3.g-1 after 6 days and no sorption was observed after 21 days. This could have been caused by a completely reversible sorption or a loss of binding capacity after 21 days [RT3]. The respective values of the biphenyl sorption partition coefficient on illite and bentonite ranged from 20.3 ± 0.3 to 120 ± 8 cm3.g-1.Sorption equilibrium on the internal clay surfaces was reached after 6 days, as indicated by the sorption data for illite and bentonite [RT4]. Access of biphenyl molecules to the internal clay surfaces is a function of the ionic strength of soil solution and the soil organic matter is the dominant site for biphenyl sorption after 6 to 21 days.
- Full Text:
- Date Issued: 2011
Polygamy in the recognition of Customary Marriages Act:
- Authors: Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141809 , vital:38006 , DOI: 10.1080/10130950.2009.9676275
- Description: The Recognition of Customary Marriages Act (RCMA) 1998, recognises customary marriages which are “negotiated, celebrated or concluded according to any of the systems of indigenous African customary law which exist in South Africa” including polygamous marriages. The Act arises in the context of South Africa's Constitution which bans discrimination on grounds of culture and sexual orientation and allows for heterogeneity in its definitions of marriage and the family. A pluralist approach to family jurisprudence, however, is sometimes conceived of as setting up an irresolvable tension between the constitutional commitment to gender equality and protection for patriarchal prerogatives sanctioned by customary law. The fact that rights sometimes collide with one another is one of the reasons why it is impossible always to treat rights as absolute. When rights clash the question that arises is which of the rights that find themselves in tension with one another should give way and why?
- Full Text:
- Date Issued: 2011
- Authors: Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141809 , vital:38006 , DOI: 10.1080/10130950.2009.9676275
- Description: The Recognition of Customary Marriages Act (RCMA) 1998, recognises customary marriages which are “negotiated, celebrated or concluded according to any of the systems of indigenous African customary law which exist in South Africa” including polygamous marriages. The Act arises in the context of South Africa's Constitution which bans discrimination on grounds of culture and sexual orientation and allows for heterogeneity in its definitions of marriage and the family. A pluralist approach to family jurisprudence, however, is sometimes conceived of as setting up an irresolvable tension between the constitutional commitment to gender equality and protection for patriarchal prerogatives sanctioned by customary law. The fact that rights sometimes collide with one another is one of the reasons why it is impossible always to treat rights as absolute. When rights clash the question that arises is which of the rights that find themselves in tension with one another should give way and why?
- Full Text:
- Date Issued: 2011
South Africa’s Abortion Values Clarification Workshops: an opportunity to deepen democratic communication missed
- Authors: Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141981 , vital:38021 , DOI: 10.1177/0021909610396161
- Description: A rich literature exists on local democracy and participation in South Africa. While the importance of participation is routinely built into the rhetoric of government, debate has increasingly focused on the dysfunctionality of participatory mechanisms and institutions in post-apartheid South Africa. Processes aimed ostensibly at empowering citizens, act in practice as instruments of social control, disempowerment and cooptation. The present article contributes to these debates by way of a critique of the approach used by the South African state, in partnership with the non-governmental sector, in what are called abortion ‘values clarification’ (VC) workshops. This article examines the workshop materials, methodology and pedagogical tools employed in South African abortion VC workshops which emanate from the organization Ipas — a global body working to enhance women’s sexual and reproductive rights and to reduce abortion-related deaths and injuries. VC workshops represent an instance of a more general trend in which participation is seen as a tool for generating legitimacy and ‘buy-in’ for central state directives rather than as a means for genuinely deepening democratic communication.
- Full Text:
- Date Issued: 2011
- Authors: Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141981 , vital:38021 , DOI: 10.1177/0021909610396161
- Description: A rich literature exists on local democracy and participation in South Africa. While the importance of participation is routinely built into the rhetoric of government, debate has increasingly focused on the dysfunctionality of participatory mechanisms and institutions in post-apartheid South Africa. Processes aimed ostensibly at empowering citizens, act in practice as instruments of social control, disempowerment and cooptation. The present article contributes to these debates by way of a critique of the approach used by the South African state, in partnership with the non-governmental sector, in what are called abortion ‘values clarification’ (VC) workshops. This article examines the workshop materials, methodology and pedagogical tools employed in South African abortion VC workshops which emanate from the organization Ipas — a global body working to enhance women’s sexual and reproductive rights and to reduce abortion-related deaths and injuries. VC workshops represent an instance of a more general trend in which participation is seen as a tool for generating legitimacy and ‘buy-in’ for central state directives rather than as a means for genuinely deepening democratic communication.
- Full Text:
- Date Issued: 2011
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