Seasonal rainfall influences on main pollutants in the Vaal River barrage reservoir: a temporal-spatial perspective
- Authors: Ochse, Estie
- Date: 2009-04-30T10:05:48Z
- Subjects: Pollutants , Water pollution , Water quality management , Vaal River (South Africa)
- Type: Thesis
- Identifier: uj:8341 , http://hdl.handle.net/10210/2467
- Description: M.A. , South Africa is situated within a semi-arid part of the world which is characterised by high seasonal variability in terms of rainfall and runoff, with high evaporation rates. This causes streamflow to be relatively low for most of the year, with seasonal sporadic high flows. Further stress is applied to the water resource through population growth, increased urbanisation and industrial activities. The study area is considered to be the most populated of the Upper Vaal Water Management Area (WMA), which is the most important WMA in terms of economic productivity in South Africa. This research report focused on assessing the temporal and spatial variations of pollution between four different sampling points located in the Vaal Barrage Reservoir, which is located in the heart of the Upper Vaal WMA. The Vaal River Barrage Reservoir forms a 64 kilometres long water body with an estimated total storage capacity of 63 million litres of water. The four sampling points are V2 (Vaal River at Engelbrechts Drift Weir); VRB 24 (Vaal River Barrage at 24 km); VRB 37 (Vaal River Barrage at 37 km) and V17 (Vaal Barrage Reservoir Outlet). The aim of this research is to determine the type of physical and chemical pollutants within the Vaal River Barrage which currently poses the biggest problem to river health. The spatial and temporal differences of the pollutant loads are established and discussed. In addition, it is determined what the seasonal influence of rainfall has on the water quality measured at the four different sampling points. Chemical pollutants which currently pose the biggest threat in terms of water quality for the Vaal Barrage Reservoir are Phosphates, Electrical Conductivity and Sulphates. These three water quality variables do not comply with the minimum standards as set by Rand Water. The occurrence of these pollutants in the Vaal River can be explained by the vast inputs of return flow water from sewage treatment plants, underground mine water and discharge from industries. Microbiological factors were not taken into consideration for this dissertation, due to the unavailability of the data for most of the sampling sites for the majority of the study period. It was found that there are seasonal variations in terms of water quality at three sampling points: VRB24, VRB37 and V17. Sample point V17 had the highest inverse correlation for the three pollutants which pose the biggest threat to the health of the Vaal Barrage Reservoir water body. This implies that high seasonal variability occurs in the pollutant load at this sampling point. Sample point V2 had extremely low inverse correlation figures, which implies that rainfall has little or no impact on the level/concentration of a pollutant. This can be explained by two factors. Firstly the dilution effect which water released from the Vaal Dam has due to the close proximity to V2. Secondly because urban, mining and industrial activities are much less evident at this point, and subsequently return flows are less.
- Full Text:
- Authors: Ochse, Estie
- Date: 2009-04-30T10:05:48Z
- Subjects: Pollutants , Water pollution , Water quality management , Vaal River (South Africa)
- Type: Thesis
- Identifier: uj:8341 , http://hdl.handle.net/10210/2467
- Description: M.A. , South Africa is situated within a semi-arid part of the world which is characterised by high seasonal variability in terms of rainfall and runoff, with high evaporation rates. This causes streamflow to be relatively low for most of the year, with seasonal sporadic high flows. Further stress is applied to the water resource through population growth, increased urbanisation and industrial activities. The study area is considered to be the most populated of the Upper Vaal Water Management Area (WMA), which is the most important WMA in terms of economic productivity in South Africa. This research report focused on assessing the temporal and spatial variations of pollution between four different sampling points located in the Vaal Barrage Reservoir, which is located in the heart of the Upper Vaal WMA. The Vaal River Barrage Reservoir forms a 64 kilometres long water body with an estimated total storage capacity of 63 million litres of water. The four sampling points are V2 (Vaal River at Engelbrechts Drift Weir); VRB 24 (Vaal River Barrage at 24 km); VRB 37 (Vaal River Barrage at 37 km) and V17 (Vaal Barrage Reservoir Outlet). The aim of this research is to determine the type of physical and chemical pollutants within the Vaal River Barrage which currently poses the biggest problem to river health. The spatial and temporal differences of the pollutant loads are established and discussed. In addition, it is determined what the seasonal influence of rainfall has on the water quality measured at the four different sampling points. Chemical pollutants which currently pose the biggest threat in terms of water quality for the Vaal Barrage Reservoir are Phosphates, Electrical Conductivity and Sulphates. These three water quality variables do not comply with the minimum standards as set by Rand Water. The occurrence of these pollutants in the Vaal River can be explained by the vast inputs of return flow water from sewage treatment plants, underground mine water and discharge from industries. Microbiological factors were not taken into consideration for this dissertation, due to the unavailability of the data for most of the sampling sites for the majority of the study period. It was found that there are seasonal variations in terms of water quality at three sampling points: VRB24, VRB37 and V17. Sample point V17 had the highest inverse correlation for the three pollutants which pose the biggest threat to the health of the Vaal Barrage Reservoir water body. This implies that high seasonal variability occurs in the pollutant load at this sampling point. Sample point V2 had extremely low inverse correlation figures, which implies that rainfall has little or no impact on the level/concentration of a pollutant. This can be explained by two factors. Firstly the dilution effect which water released from the Vaal Dam has due to the close proximity to V2. Secondly because urban, mining and industrial activities are much less evident at this point, and subsequently return flows are less.
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Synthesis of graphene oxide (GO) decorated CuInS2/ZnS core/shell quantum dots (QDs) as fluorescence probe for the detection of environmental pollutants
- Authors: Maluleke, Rodney
- Date: 2020
- Subjects: Graphene - Oxidation , Quantum dots , Pollutants , Organic water pollutants , Organic compounds - Synthesis , Fluorescent probes
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/458509 , uj:40728
- Description: Abstract: Recently, an increasing number of organic compounds including polycyclic aromatic hydrocarbons (PAHs) and nitro-aromatic compounds (NACs) are being released into the environment and most of them are hazardous to living organisms and ecosystems. Thus, the detection of those organic pollutants has become a major concern. Until now various techniques have been used to sense organic pollutants, and such methods have included surface-enhanced Raman spectroscopy (SERS), gas chromatography coupled with mass spectrometry (GC–MS), plasma desorption mass spectrometry (PDMS), energy dispersive X-ray diffraction (EDXRD), and various spectral imaging techniques. However, these conventional methods are not low-cost, not environmentally-friendly, not portable, and not suitable for rapid field detection. Over the past decades, fluorescence technology using organic pollutants detection provides an attractive and promising alternative owing to its unique advantages which include cost-effectiveness, environmentally-friendliness, rapid response and good portability. Therefore, this study explored aqueous synthesis, characterisation and application of CuInS2/ZnS-GO fluorescent probe for the fluorescence detection of the selected organic compounds such as polycyclic aromatic hydrocarbons and nitro-aromatic compounds in aqueous phase. The pollutants are; phenanthrene (Phe), pyrene (Py) and naphthalene (Naph) and trinitrophenol (TNP). A fluorescent nanocomposite was prepared by decorating graphene oxide (GO) with glutathione (GSH)-capped CuInS2/ZnS core/shell quantum dots (QDs). The composite was prepared via in-situ synthesis in which glutathione (GSH) and sodium citrate were used as dual stabilizers. The quantum dots nanocomposite was prepared through non- covalent functionalization of QDs with graphene oxide (GO). The as-synthesized composite was characterised using UV-Vis absorption, photoluminescence (PL) vi spectroscopy, high resolution transmission electron microscopy (HR-TEM), Fourier- transform infrared spectroscopy (FT-IR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and Raman scattering. The photoluminescence (PL) spectrophotometry revealed the Forster resonance energy transfer (FRET) between the QDs and GO. The Raman scattering revealed the presence of QDs on the GO nanosheets. The TEM showed that the QDs were well distributed on the GO nanosheets. This was in agreement with the UV absorption bands which revealed the excitonic peaks for the QDs and the QDs-GO. In addition, the XRD patterns confirmed the crystalline nature of the as-prepared materials. The sensing studies indicated that the fluorescence intensity of the QDs-GO nanocomposite can be increased by both PAHs and NACs. However, the fluorescence intensity of pristine QDs does not show changes in the presence of PAHs. Though the presence of PAHs in the QDs did not show significant changes in the fluorescence intensity, however, the presence of the NAC, TNP, caused the fluorescence intensity of the QDs to decrease. , M.Sc. (Chemistry)
- Full Text:
- Authors: Maluleke, Rodney
- Date: 2020
- Subjects: Graphene - Oxidation , Quantum dots , Pollutants , Organic water pollutants , Organic compounds - Synthesis , Fluorescent probes
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/458509 , uj:40728
- Description: Abstract: Recently, an increasing number of organic compounds including polycyclic aromatic hydrocarbons (PAHs) and nitro-aromatic compounds (NACs) are being released into the environment and most of them are hazardous to living organisms and ecosystems. Thus, the detection of those organic pollutants has become a major concern. Until now various techniques have been used to sense organic pollutants, and such methods have included surface-enhanced Raman spectroscopy (SERS), gas chromatography coupled with mass spectrometry (GC–MS), plasma desorption mass spectrometry (PDMS), energy dispersive X-ray diffraction (EDXRD), and various spectral imaging techniques. However, these conventional methods are not low-cost, not environmentally-friendly, not portable, and not suitable for rapid field detection. Over the past decades, fluorescence technology using organic pollutants detection provides an attractive and promising alternative owing to its unique advantages which include cost-effectiveness, environmentally-friendliness, rapid response and good portability. Therefore, this study explored aqueous synthesis, characterisation and application of CuInS2/ZnS-GO fluorescent probe for the fluorescence detection of the selected organic compounds such as polycyclic aromatic hydrocarbons and nitro-aromatic compounds in aqueous phase. The pollutants are; phenanthrene (Phe), pyrene (Py) and naphthalene (Naph) and trinitrophenol (TNP). A fluorescent nanocomposite was prepared by decorating graphene oxide (GO) with glutathione (GSH)-capped CuInS2/ZnS core/shell quantum dots (QDs). The composite was prepared via in-situ synthesis in which glutathione (GSH) and sodium citrate were used as dual stabilizers. The quantum dots nanocomposite was prepared through non- covalent functionalization of QDs with graphene oxide (GO). The as-synthesized composite was characterised using UV-Vis absorption, photoluminescence (PL) vi spectroscopy, high resolution transmission electron microscopy (HR-TEM), Fourier- transform infrared spectroscopy (FT-IR), Ultraviolet–visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and Raman scattering. The photoluminescence (PL) spectrophotometry revealed the Forster resonance energy transfer (FRET) between the QDs and GO. The Raman scattering revealed the presence of QDs on the GO nanosheets. The TEM showed that the QDs were well distributed on the GO nanosheets. This was in agreement with the UV absorption bands which revealed the excitonic peaks for the QDs and the QDs-GO. In addition, the XRD patterns confirmed the crystalline nature of the as-prepared materials. The sensing studies indicated that the fluorescence intensity of the QDs-GO nanocomposite can be increased by both PAHs and NACs. However, the fluorescence intensity of pristine QDs does not show changes in the presence of PAHs. Though the presence of PAHs in the QDs did not show significant changes in the fluorescence intensity, however, the presence of the NAC, TNP, caused the fluorescence intensity of the QDs to decrease. , M.Sc. (Chemistry)
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The risks associated with wastewater reuse
- Authors: Rambau, L.D.
- Date: 2019
- Subjects: Sewage , Pollutants , Sewage - Purification
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/393636 , uj:32576
- Description: Abstract: Water scarcity has become a major problem in South Africa. Wastewater reuse is one of the most important strategies dealing with the water scarcity problem. The focus of this research is on the field of water and wastewater reuse. South Africa has a significant number of wastewater treatment plants. Most of these do not currently comply with the standards required for the discharge of water containing waste. Poor operation, maintenance and management of wastewater treatment plants are considered a risk to both the environment and human health. Wastewater should be treated to acceptable standards and returned to watercourses from where it was originally obtained. The research problem is that there is a lack of comprehension of all the risks involved in the reclamation of wastewater sites in South Africa. Therefore, the aim of this study was to highlight the risks associated with wastewater reuse and develop appropriate risk management strategies to mitigate these. A survey was used as a quantitative research strategy. A significant response rate of 67% of the sample of managers was obtained. It was found that wastewater is mainly discharged directly into water bodies such as rivers or streams. It was found that wastewater reuse sometimes posed a risk mostly to surface water pollution. It was also noted that mitigation strategies such as complying with the required water quality standards, implementing and complying with wastewater management plans, continuous operational and compliance monitoring with remedial plans, and appropriate wastewater technology were the most common mitigation strategies that are used every time. The research outcomes of the study are beneficial to organisations that have wastewater treatment plants as well as the government of South Africa. The recommendations made would benefit the user organisations to continually improve their processes so as to mitigate the risks associated with wastewater reuse. Furthermore, the results of the study add value to the body of knowledge. Risk management of wastewater reuse will ensure that all risks to human health and the integrity of industrial processes are reduced adequately. , M.Phil. (Engineering Management)
- Full Text:
- Authors: Rambau, L.D.
- Date: 2019
- Subjects: Sewage , Pollutants , Sewage - Purification
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/393636 , uj:32576
- Description: Abstract: Water scarcity has become a major problem in South Africa. Wastewater reuse is one of the most important strategies dealing with the water scarcity problem. The focus of this research is on the field of water and wastewater reuse. South Africa has a significant number of wastewater treatment plants. Most of these do not currently comply with the standards required for the discharge of water containing waste. Poor operation, maintenance and management of wastewater treatment plants are considered a risk to both the environment and human health. Wastewater should be treated to acceptable standards and returned to watercourses from where it was originally obtained. The research problem is that there is a lack of comprehension of all the risks involved in the reclamation of wastewater sites in South Africa. Therefore, the aim of this study was to highlight the risks associated with wastewater reuse and develop appropriate risk management strategies to mitigate these. A survey was used as a quantitative research strategy. A significant response rate of 67% of the sample of managers was obtained. It was found that wastewater is mainly discharged directly into water bodies such as rivers or streams. It was found that wastewater reuse sometimes posed a risk mostly to surface water pollution. It was also noted that mitigation strategies such as complying with the required water quality standards, implementing and complying with wastewater management plans, continuous operational and compliance monitoring with remedial plans, and appropriate wastewater technology were the most common mitigation strategies that are used every time. The research outcomes of the study are beneficial to organisations that have wastewater treatment plants as well as the government of South Africa. The recommendations made would benefit the user organisations to continually improve their processes so as to mitigate the risks associated with wastewater reuse. Furthermore, the results of the study add value to the body of knowledge. Risk management of wastewater reuse will ensure that all risks to human health and the integrity of industrial processes are reduced adequately. , M.Phil. (Engineering Management)
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