The use of bioassays to assess the toxicity of sediment in an acid mine drainage impacted river in Gauteng (South Africa)
- Singh, P., Nel, A., Durand, J. F.
- Authors: Singh, P. , Nel, A. , Durand, J. F.
- Date: 2017
- Subjects: Acid mine drainage , Sediment toxicity , Bioassay
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251795 , uj:26232 , Citation: Singh, P., Nel, A. & Durand, J. F. 2017. The use of bioassays to assess the toxicity of sediment in an acid mine drainage impacted river in Gauteng (South Africa).
- Description: Abstract: Sediment contamination may occur from various anthropogenic activities, such as mining-, agricultural- and industrial practices. Many of the contaminants arising from these activities enter the aquatic system and precipitate from the surrounding water, becoming bound to sediment particles. These bound contaminants may reach concentrations higher than in the overlying water. Although water quality may be acceptable, an aquatic system may still be at risk if the contaminated sediment were to be disturbed through flooding, bioturbation or changes in the water chemistry. These contaminants may then desorb into the water column and prove detrimental to life forms in contact and dependent on that water source. Sediment quality monitoring has been a widespread international initiative and has led to the development of sediment toxicity assessment methods. This study focused on sediment bioassays, namely, Phytotoxkit, Ostracodtoxkit F and the Diptera bioassay, in assessing sediment quality of the Tweelopiespruit-Rietspruit-Bloubankspruit river system in Gauteng, South Africa. This river is known to have been impacted by acid mine drainage (AMD) since late August, 2002. Exposure of river sediment from 7 sampling sites to these bioassays provided an eco-toxicological estimation of the acute toxicity and chronic toxicity emanating from the contaminated sediments. Physico-chemical analyses revealed higher levels of sediment contamination closer to the mine. The bioassays displayed a similar trend with greater sensitivities to sediments closer to the mine and lower sensitivities to the less contaminated sites further downstream. AMD was therefore the main driver for sediment contamination. Whilst not all contaminants were bioavailable, statistical analysis showed that there were significant correlations between the elevated contaminant concentrations closer to the mine and bioassay responses.
- Full Text:
- Authors: Singh, P. , Nel, A. , Durand, J. F.
- Date: 2017
- Subjects: Acid mine drainage , Sediment toxicity , Bioassay
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251795 , uj:26232 , Citation: Singh, P., Nel, A. & Durand, J. F. 2017. The use of bioassays to assess the toxicity of sediment in an acid mine drainage impacted river in Gauteng (South Africa).
- Description: Abstract: Sediment contamination may occur from various anthropogenic activities, such as mining-, agricultural- and industrial practices. Many of the contaminants arising from these activities enter the aquatic system and precipitate from the surrounding water, becoming bound to sediment particles. These bound contaminants may reach concentrations higher than in the overlying water. Although water quality may be acceptable, an aquatic system may still be at risk if the contaminated sediment were to be disturbed through flooding, bioturbation or changes in the water chemistry. These contaminants may then desorb into the water column and prove detrimental to life forms in contact and dependent on that water source. Sediment quality monitoring has been a widespread international initiative and has led to the development of sediment toxicity assessment methods. This study focused on sediment bioassays, namely, Phytotoxkit, Ostracodtoxkit F and the Diptera bioassay, in assessing sediment quality of the Tweelopiespruit-Rietspruit-Bloubankspruit river system in Gauteng, South Africa. This river is known to have been impacted by acid mine drainage (AMD) since late August, 2002. Exposure of river sediment from 7 sampling sites to these bioassays provided an eco-toxicological estimation of the acute toxicity and chronic toxicity emanating from the contaminated sediments. Physico-chemical analyses revealed higher levels of sediment contamination closer to the mine. The bioassays displayed a similar trend with greater sensitivities to sediments closer to the mine and lower sensitivities to the less contaminated sites further downstream. AMD was therefore the main driver for sediment contamination. Whilst not all contaminants were bioavailable, statistical analysis showed that there were significant correlations between the elevated contaminant concentrations closer to the mine and bioassay responses.
- Full Text:
Importance of emotional intelligence in conceptualizing collegial leadership in education
- Singh, P., Manser, P., Mestry, R.
- Authors: Singh, P. , Manser, P. , Mestry, R.
- Date: 2007
- Subjects: Collegial leadership , Emotional intelligence , Emotionally intelligent behaviours , Triumvirate Leadership grid , Collegiality , Educational leadership
- Type: Article
- Identifier: uj:5747 , ISSN 2076-3433 , http://hdl.handle.net/10210/7749
- Description: We focus on the importance of emotional intelligence (EI) in conceptualizing collegial leadership in education. Research findings, both nationally and internationally, strongly suggest that a technocratic (managerial) approach to leadership is in conflict with the visionary, people-centred approach of modern organisations, including educational institution s at school level. Research on leadership over the past two decades indicates that the emotional intelligence of leaders matters twice as much as cognitive abilities such as IQ or technical expertise. EIis not in opposition to IQ bu t it is an extension of the human’s potential to succeed in a people-orientated environment. Traditional cognitive intelligence (IQ) is combined with no n-cognitive intelligence (EI) to help leaders perform at their best and inspire their followers to be successful and happy. Although the principal’s leadership is an essential element in the success of a school, current research indicates that the complexities o f schools require a new focus on collaborative (collegial) leadership. This research on EI, collegial leadership, and job satisfaction is illustrated in the Triumvirate Leadership Grid. It strongly suggests th at a personal and emotional accountability system is essential for positive human development within the learning environment.
- Full Text:
- Authors: Singh, P. , Manser, P. , Mestry, R.
- Date: 2007
- Subjects: Collegial leadership , Emotional intelligence , Emotionally intelligent behaviours , Triumvirate Leadership grid , Collegiality , Educational leadership
- Type: Article
- Identifier: uj:5747 , ISSN 2076-3433 , http://hdl.handle.net/10210/7749
- Description: We focus on the importance of emotional intelligence (EI) in conceptualizing collegial leadership in education. Research findings, both nationally and internationally, strongly suggest that a technocratic (managerial) approach to leadership is in conflict with the visionary, people-centred approach of modern organisations, including educational institution s at school level. Research on leadership over the past two decades indicates that the emotional intelligence of leaders matters twice as much as cognitive abilities such as IQ or technical expertise. EIis not in opposition to IQ bu t it is an extension of the human’s potential to succeed in a people-orientated environment. Traditional cognitive intelligence (IQ) is combined with no n-cognitive intelligence (EI) to help leaders perform at their best and inspire their followers to be successful and happy. Although the principal’s leadership is an essential element in the success of a school, current research indicates that the complexities o f schools require a new focus on collaborative (collegial) leadership. This research on EI, collegial leadership, and job satisfaction is illustrated in the Triumvirate Leadership Grid. It strongly suggests th at a personal and emotional accountability system is essential for positive human development within the learning environment.
- Full Text:
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