Characterization and pre-treatment of water from the Vaal River
- Vessal, Ali R., Ntuli, Freeman, Ngoie, Sonia K.
- Authors: Vessal, Ali R. , Ntuli, Freeman , Ngoie, Sonia K.
- Date: 2015-07-14
- Subjects: Water quality , Vaal River (South Africa) , Water - Pollution - Control
- Type: Article
- Identifier: uj:5242 , http://hdl.handle.net/10210/14842
- Description: Extensive urbanization, economic development, and industrialization coupled with water wastage are placing increased pressure on the quality of water from the Vaal River system. This research study was carried out to assess the water quality of the Vaal River in terms of physico-chemical parameters and heavy metals concentration. Three (3) locations were identified within the Upper Vaal Water Management Area (WMA) where water samples were collected in the months of July and September 2014. A total of eight water quality parameters namely pH, Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Total Hardness (CaCO3), Chemical Oxygen Demand (COD), Nitrate (NO3-), Phosphate (PO43-), Sulphate (SO42-) and Heavy Metals concentration were measured in the laboratory using standard analytical procedures. Values of measured parameters were then compared with the South African water quality guidelines for domestic use and aquatic ecosystems. The findings showed that all the physico-chemical parameters and heavy metals concentration measured were within the tolerable limits except nitrate which exceeded the recommended limit of 6 mg/l, with values ranging from 30-31 mg/l in July and 19-21 mg/l in September. The analytical data also indicated that after pre-treatment of the water sample by filtration and adsorption, the TSS level, TDS concentration, and nitrate content were significantly lowered. Nitrate was reduced to below the acceptable limit after treatment. It was therefore concluded that the river water in the Upper Vaal Water Management Area was not suitable for domestic purposes without any form of treatment and frequent monitoring of physico-chemical parameters is imperative in order to have a full representation of the variations in the water quality.
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- Authors: Vessal, Ali R. , Ntuli, Freeman , Ngoie, Sonia K.
- Date: 2015-07-14
- Subjects: Water quality , Vaal River (South Africa) , Water - Pollution - Control
- Type: Article
- Identifier: uj:5242 , http://hdl.handle.net/10210/14842
- Description: Extensive urbanization, economic development, and industrialization coupled with water wastage are placing increased pressure on the quality of water from the Vaal River system. This research study was carried out to assess the water quality of the Vaal River in terms of physico-chemical parameters and heavy metals concentration. Three (3) locations were identified within the Upper Vaal Water Management Area (WMA) where water samples were collected in the months of July and September 2014. A total of eight water quality parameters namely pH, Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Total Hardness (CaCO3), Chemical Oxygen Demand (COD), Nitrate (NO3-), Phosphate (PO43-), Sulphate (SO42-) and Heavy Metals concentration were measured in the laboratory using standard analytical procedures. Values of measured parameters were then compared with the South African water quality guidelines for domestic use and aquatic ecosystems. The findings showed that all the physico-chemical parameters and heavy metals concentration measured were within the tolerable limits except nitrate which exceeded the recommended limit of 6 mg/l, with values ranging from 30-31 mg/l in July and 19-21 mg/l in September. The analytical data also indicated that after pre-treatment of the water sample by filtration and adsorption, the TSS level, TDS concentration, and nitrate content were significantly lowered. Nitrate was reduced to below the acceptable limit after treatment. It was therefore concluded that the river water in the Upper Vaal Water Management Area was not suitable for domestic purposes without any form of treatment and frequent monitoring of physico-chemical parameters is imperative in order to have a full representation of the variations in the water quality.
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Atmospheric oxidative and non-oxidative leaching of Ni-Cu matte by acidified ferric chloride solution
- Sekhukhune, L.M., Ntuli, Freeman, Muzenda, Edison
- Authors: Sekhukhune, L.M. , Ntuli, Freeman , Muzenda, Edison
- Date: 2014
- Subjects: Ni-Cu matte , Acid leaching , Cementation , Ferric chloride , Leaching mechanism
- Type: Article
- Identifier: uj:4765 , ISSN 0038-223X , http://hdl.handle.net/10210/11940
- Description: The atmospheric leaching of copper-bearing matte by acidic ferric chloride solution was studied at the laboratory scale. The aim was to achieve maximum copper and nickel recovery by investigating the mechanisms of leaching, as well as identifying the effect of temperature, and concentration of ferric chloride and oxygen...
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- Authors: Sekhukhune, L.M. , Ntuli, Freeman , Muzenda, Edison
- Date: 2014
- Subjects: Ni-Cu matte , Acid leaching , Cementation , Ferric chloride , Leaching mechanism
- Type: Article
- Identifier: uj:4765 , ISSN 0038-223X , http://hdl.handle.net/10210/11940
- Description: The atmospheric leaching of copper-bearing matte by acidic ferric chloride solution was studied at the laboratory scale. The aim was to achieve maximum copper and nickel recovery by investigating the mechanisms of leaching, as well as identifying the effect of temperature, and concentration of ferric chloride and oxygen...
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Management and control of industrial effluents discharged to public sewers : a case study
- Authors: Ntuli, Freeman
- Date: 2012
- Subjects: Biodegradability , Public sewers , Sewerage management , Industrial effluents
- Type: Article
- Identifier: uj:6048 , ISSN 2010-376X , http://hdl.handle.net/10210/10457
- Description: An overview of the important aspects of managing and controlling industrial effluent discharges to public sewers namely sampling, characterization, quantification and legislative controls has been presented. The findings have been validated by means of a case study covering three industrial sectors namely, tanning, textile finishing and food processing industries. Industrial effluents discharges were found to be best monitored by systematic and automatic sampling and quantified using water meter readings corrected for evaporative and consumptive losses. Based on the treatment processes employed in the public owned treatment works and the chemical oxygen demand and biochemical oxygen demand levels obtained, the effluent from all the three industrial sectors studied were found to lie in the toxic zone. Thus, physico-chemical treatment of these effluents is required to bring them into the biodegradable zone...
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- Authors: Ntuli, Freeman
- Date: 2012
- Subjects: Biodegradability , Public sewers , Sewerage management , Industrial effluents
- Type: Article
- Identifier: uj:6048 , ISSN 2010-376X , http://hdl.handle.net/10210/10457
- Description: An overview of the important aspects of managing and controlling industrial effluent discharges to public sewers namely sampling, characterization, quantification and legislative controls has been presented. The findings have been validated by means of a case study covering three industrial sectors namely, tanning, textile finishing and food processing industries. Industrial effluents discharges were found to be best monitored by systematic and automatic sampling and quantified using water meter readings corrected for evaporative and consumptive losses. Based on the treatment processes employed in the public owned treatment works and the chemical oxygen demand and biochemical oxygen demand levels obtained, the effluent from all the three industrial sectors studied were found to lie in the toxic zone. Thus, physico-chemical treatment of these effluents is required to bring them into the biodegradable zone...
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The effect of leaching time and ammonia concentration on the atmospheric leaching of copper
- Ntuli, Freeman, Muzenda, Edison, Ramatsa, Ishmael, Belaid, Mohamed, Kabuba, John
- Authors: Ntuli, Freeman , Muzenda, Edison , Ramatsa, Ishmael , Belaid, Mohamed , Kabuba, John
- Date: 2013
- Subjects: Ammonia , Cementation , Concentration , Leaching
- Language: English
- Type: Conference
- Identifier: http://hdl.handle.net/10210/17348 , uj:15872 , F. Ntuli, E. et al. 2013. The effect of leaching time and ammonia concentration on the atmospheric leaching of copper. 2nd International Conference on Chemistry and Chemical Engineering, IPCBEE vol.14, Singapore 2011. Cited by: KG Tshilombo, AF Mulaba-Bafubiandi - Magnesium, 2013 - psrcentre.org
- Description: Abstract: Please refer to full text for abstract.
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- Authors: Ntuli, Freeman , Muzenda, Edison , Ramatsa, Ishmael , Belaid, Mohamed , Kabuba, John
- Date: 2013
- Subjects: Ammonia , Cementation , Concentration , Leaching
- Language: English
- Type: Conference
- Identifier: http://hdl.handle.net/10210/17348 , uj:15872 , F. Ntuli, E. et al. 2013. The effect of leaching time and ammonia concentration on the atmospheric leaching of copper. 2nd International Conference on Chemistry and Chemical Engineering, IPCBEE vol.14, Singapore 2011. Cited by: KG Tshilombo, AF Mulaba-Bafubiandi - Magnesium, 2013 - psrcentre.org
- Description: Abstract: Please refer to full text for abstract.
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The effect of leaching time and ammonia concentration on the atmospheric leaching of copper
- Ntuli, Freeman, Muzenda, Edison, Ramatsa, Ishmael, Belaid, Mohamed, Kabuba, John
- Authors: Ntuli, Freeman , Muzenda, Edison , Ramatsa, Ishmael , Belaid, Mohamed , Kabuba, John
- Date: 2011
- Subjects: Copper recovery , Leaching , Ammonia concentrations
- Type: Article
- Identifier: uj:5319 , ISSN 2010-4618 , http://hdl.handle.net/10210/8195
- Description: The effects of ammonia concentration and leaching time were investigated to determine the optimum leaching conditions. The experiments were conducted in a leaching cell submerged in a water bath, with ammonia concentrations of 1.5 M, 2.0 M, 2.5 M and 3.0 M and varying leaching time from 0 to 300 min. Ni-Cu matte containing 23% by mass Cu was used in this experimental study. Increase in the concentration of the lixiviant was found to increase recovery when leaching for 130 minutes, with a recovery of 32.86% Cu using 3 M solution of ammonia. An increase in the leaching time resulted in more copper being leached for all lixiviant concentrations. However, leaching with 2 M ammonia solution gave a higher yield of copper compared to higher concentrations. This anomaly could be a result of cementation; Cu is displaced by Ni as Ni is a more electronegative metal than Cu .It was found that at higher concentrations more nickel was extracted.
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- Authors: Ntuli, Freeman , Muzenda, Edison , Ramatsa, Ishmael , Belaid, Mohamed , Kabuba, John
- Date: 2011
- Subjects: Copper recovery , Leaching , Ammonia concentrations
- Type: Article
- Identifier: uj:5319 , ISSN 2010-4618 , http://hdl.handle.net/10210/8195
- Description: The effects of ammonia concentration and leaching time were investigated to determine the optimum leaching conditions. The experiments were conducted in a leaching cell submerged in a water bath, with ammonia concentrations of 1.5 M, 2.0 M, 2.5 M and 3.0 M and varying leaching time from 0 to 300 min. Ni-Cu matte containing 23% by mass Cu was used in this experimental study. Increase in the concentration of the lixiviant was found to increase recovery when leaching for 130 minutes, with a recovery of 32.86% Cu using 3 M solution of ammonia. An increase in the leaching time resulted in more copper being leached for all lixiviant concentrations. However, leaching with 2 M ammonia solution gave a higher yield of copper compared to higher concentrations. This anomaly could be a result of cementation; Cu is displaced by Ni as Ni is a more electronegative metal than Cu .It was found that at higher concentrations more nickel was extracted.
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Adsorption of Cu and Ni from AMD using activated bentonite
- Ntuli, Freeman, Falayi, Thabo, Molala, Panelope
- Authors: Ntuli, Freeman , Falayi, Thabo , Molala, Panelope
- Date: 2014
- Subjects: Bentonite , Copper adsorption , Langmuir kinetic models , Nickel adsorption
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/387938 , uj:4901 , ISSN 2349-1442 , http://hdl.handle.net/10210/12996
- Description: The ability of activated bentonite to adsorb Cu and Ni was investigated. 6 % solid loading was chosen as the optimum solid loading for activated bentonite with 94.85% Cu and 92.05% Ni removal after 3 hours of agitation. The adsorption process followed the Langmuir isotherm and pseudo second order kinetic models. The maximum adsorption capacities were 0.297 and 0.235 mg/g for Cu and Ni respectively. The adsorption of Cu and Ni was thermodynamically spontaneous. Cu adsorption was endothermic whilst Ni adsorption was exothermic. Activated bentonite could be used for two cycles of adsorption without regeneration.
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- Authors: Ntuli, Freeman , Falayi, Thabo , Molala, Panelope
- Date: 2014
- Subjects: Bentonite , Copper adsorption , Langmuir kinetic models , Nickel adsorption
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/387938 , uj:4901 , ISSN 2349-1442 , http://hdl.handle.net/10210/12996
- Description: The ability of activated bentonite to adsorb Cu and Ni was investigated. 6 % solid loading was chosen as the optimum solid loading for activated bentonite with 94.85% Cu and 92.05% Ni removal after 3 hours of agitation. The adsorption process followed the Langmuir isotherm and pseudo second order kinetic models. The maximum adsorption capacities were 0.297 and 0.235 mg/g for Cu and Ni respectively. The adsorption of Cu and Ni was thermodynamically spontaneous. Cu adsorption was endothermic whilst Ni adsorption was exothermic. Activated bentonite could be used for two cycles of adsorption without regeneration.
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Adsorption, kinetic and thermodynamic study of Al, Mn and Fe adsorption with natural attapulgite
- Ntuli, Freeman, Falayi, Thabo, Mabasa, Cyril
- Authors: Ntuli, Freeman , Falayi, Thabo , Mabasa, Cyril
- Date: 2015
- Subjects: Attapulgite , Aluminum , Manganese , Iron , Adsorption
- Type: Article
- Identifier: uj:5126 , ISBN 978-1-61804-270-5 , http://hdl.handle.net/10210/14089
- Description: Natural attapulgite was utilized as an adsorbent for the removal of Al, Fe and Mn from a mixed metal effluent. Adsorption experiments were carried out by agitation of a fixed amount of attapulgite with a fixed volume of effluent waste stream in a thermostatic shaker for varying times. Attapulgite showed that it was capable of neutralising the acidic waste stream effluent as pH after 3 hour rose from 2 to 7.46. 4% solid loading of attapulgite could remove 85% Mn(II), 90% Al(III) and 100% Fe(III) The experimental data best fit Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models and the adsorption mechanism was physisorption. The adsorption process fitted well the pseudo second order kinetics for all metal ions studied. Thermodynamic data showed that Fe(III) and Mn(II) adsorption was thermodynamically spontaneous whilst Al(III) was not thermodynamically spontaneous. The process is endothermic for all metal ions. An increase in temperature resulted in an increase in spontaneity of the adsorption process. An increase in metal concentration resulted in an increase in amount of metal ion adsorbed per unit weight of attapulgite.
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- Authors: Ntuli, Freeman , Falayi, Thabo , Mabasa, Cyril
- Date: 2015
- Subjects: Attapulgite , Aluminum , Manganese , Iron , Adsorption
- Type: Article
- Identifier: uj:5126 , ISBN 978-1-61804-270-5 , http://hdl.handle.net/10210/14089
- Description: Natural attapulgite was utilized as an adsorbent for the removal of Al, Fe and Mn from a mixed metal effluent. Adsorption experiments were carried out by agitation of a fixed amount of attapulgite with a fixed volume of effluent waste stream in a thermostatic shaker for varying times. Attapulgite showed that it was capable of neutralising the acidic waste stream effluent as pH after 3 hour rose from 2 to 7.46. 4% solid loading of attapulgite could remove 85% Mn(II), 90% Al(III) and 100% Fe(III) The experimental data best fit Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models and the adsorption mechanism was physisorption. The adsorption process fitted well the pseudo second order kinetics for all metal ions studied. Thermodynamic data showed that Fe(III) and Mn(II) adsorption was thermodynamically spontaneous whilst Al(III) was not thermodynamically spontaneous. The process is endothermic for all metal ions. An increase in temperature resulted in an increase in spontaneity of the adsorption process. An increase in metal concentration resulted in an increase in amount of metal ion adsorbed per unit weight of attapulgite.
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Designing of sampling programmes for industrial effluent monitoring
- Ntuli, Freeman, Kuipa, P.K., Muzenda, Edison
- Authors: Ntuli, Freeman , Kuipa, P.K. , Muzenda, Edison
- Date: 2011
- Subjects: Effluent monitoring , Sampling strategies , Water pollution control , Sampling (Statistics)
- Type: Article
- Identifier: uj:5313 , ISSN 0944-1344 , http://hdl.handle.net/10210/7736
- Description: Monitoring of effluent discharges from industrial establishments discharging directly into municipality sewers is one of the major water pollution control activities conducted by municipalities. For largely industrialised municipalities the task can be quite expensive and not effective if sampling programmes are not properly designed. In most cases samples are randomly collected without proper knowledge of the discharge patterns of various industries. As a result the information obtained does not give a good reflection of the quality of effluent being discharged. These problems can be resolved by adapting a statistical approach to the design of sampling programmes. This approach is useful in determining the frequency of sampling, the number of samples needed to estimate the average concentration of target pollution indicator parameters and the magnitude of the uncertainty involved. The benefits and applications of this approach are demonstrated by a case study presented in this paper. It was found that the number of samples and cost of sample analysis can be greatly reduced by the use of systematic instead of random sampling. The statistical approach greatly improves the estimate of monthly means of pollution indicator parameters and is an effective approach for pollution control when coupled with the “polluter pays principle”.
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- Authors: Ntuli, Freeman , Kuipa, P.K. , Muzenda, Edison
- Date: 2011
- Subjects: Effluent monitoring , Sampling strategies , Water pollution control , Sampling (Statistics)
- Type: Article
- Identifier: uj:5313 , ISSN 0944-1344 , http://hdl.handle.net/10210/7736
- Description: Monitoring of effluent discharges from industrial establishments discharging directly into municipality sewers is one of the major water pollution control activities conducted by municipalities. For largely industrialised municipalities the task can be quite expensive and not effective if sampling programmes are not properly designed. In most cases samples are randomly collected without proper knowledge of the discharge patterns of various industries. As a result the information obtained does not give a good reflection of the quality of effluent being discharged. These problems can be resolved by adapting a statistical approach to the design of sampling programmes. This approach is useful in determining the frequency of sampling, the number of samples needed to estimate the average concentration of target pollution indicator parameters and the magnitude of the uncertainty involved. The benefits and applications of this approach are demonstrated by a case study presented in this paper. It was found that the number of samples and cost of sample analysis can be greatly reduced by the use of systematic instead of random sampling. The statistical approach greatly improves the estimate of monthly means of pollution indicator parameters and is an effective approach for pollution control when coupled with the “polluter pays principle”.
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Characterization of effluent from textile wet finishing operations
- Ntuli, Freeman, Ikhu-Omoregbe, Daniel, Kuipa, Pardon K., Muzenda, Edison, Belaid, Mohamed
- Authors: Ntuli, Freeman , Ikhu-Omoregbe, Daniel , Kuipa, Pardon K. , Muzenda, Edison , Belaid, Mohamed
- Date: 2009
- Subjects: Effluent characterization , Effluent pre-treatment , Textile - Wet processing
- Type: Article
- Identifier: uj:4718 , ISSN 978-988-17012-6-8 , http://hdl.handle.net/10210/10972
- Description: Please refer to full text to view abstract
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- Authors: Ntuli, Freeman , Ikhu-Omoregbe, Daniel , Kuipa, Pardon K. , Muzenda, Edison , Belaid, Mohamed
- Date: 2009
- Subjects: Effluent characterization , Effluent pre-treatment , Textile - Wet processing
- Type: Article
- Identifier: uj:4718 , ISSN 978-988-17012-6-8 , http://hdl.handle.net/10210/10972
- Description: Please refer to full text to view abstract
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Thermally activated attapulgite as an adsorbent for heavy metals
- Ntuli, Freeman, Falayi, Thabo, Dlamini, Thabani
- Authors: Ntuli, Freeman , Falayi, Thabo , Dlamini, Thabani
- Date: 2013
- Subjects: Adsorption , Attapulgite , Heavy metals , Langmuir isotherm
- Type: Article
- Identifier: uj:4854 , http://hdl.handle.net/10210/12530
- Description: Thermal activation of attapulgite was investigated. Attapulgite calcined at 6000C was used as an adsorbent for heavy metals in AMD. The effect of solid loading, residence time and adsorption temperature was investigated. Activated attapulgite showed that it could remove more than 99% of Fe, Cu, Co and Ni from AMD. Langmuir isotherm gave the best fit for the adsorption process with maximum adsorption capacities of 8.97, 0.20, 0.32 and 0.32 for Fe, Ni, Cu and Co respectively. The adsorption of Cu and Ni was thermodynamically. The results show that thermally activated attapulgite has potential as an adsorbent for heavy metals from AMD.
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- Authors: Ntuli, Freeman , Falayi, Thabo , Dlamini, Thabani
- Date: 2013
- Subjects: Adsorption , Attapulgite , Heavy metals , Langmuir isotherm
- Type: Article
- Identifier: uj:4854 , http://hdl.handle.net/10210/12530
- Description: Thermal activation of attapulgite was investigated. Attapulgite calcined at 6000C was used as an adsorbent for heavy metals in AMD. The effect of solid loading, residence time and adsorption temperature was investigated. Activated attapulgite showed that it could remove more than 99% of Fe, Cu, Co and Ni from AMD. Langmuir isotherm gave the best fit for the adsorption process with maximum adsorption capacities of 8.97, 0.20, 0.32 and 0.32 for Fe, Ni, Cu and Co respectively. The adsorption of Cu and Ni was thermodynamically. The results show that thermally activated attapulgite has potential as an adsorbent for heavy metals from AMD.
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Extraction and precipitation of phosphorous from sewage sludge : a feasibility study.
- Ntuli, Freeman, Falayi, Thabo, Mhlungu, Mbalenhle, Thifhelimbilu, Portia
- Authors: Ntuli, Freeman , Falayi, Thabo , Mhlungu, Mbalenhle , Thifhelimbilu, Portia
- Date: 2013
- Subjects: Sewage sludge , Phosphorous
- Type: Article
- Identifier: uj:4855 , http://hdl.handle.net/10210/12531
- Description: Sewage sludge from ERWAT (East Rand Water Care Company) was investigated to determine its potential as a source of P. The raw sewage sludge was found to be a potential source of P. At least 84% P could be leached from the raw sewage sludge after 60 min using either HCl or H2SO4. Selective precipitation of P as magnesium tetraphosphate could be achieved using ammonia and magnesium oxide to give yield a 92.2% pure magnesium tetraphosphate and 9.8% P.
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- Authors: Ntuli, Freeman , Falayi, Thabo , Mhlungu, Mbalenhle , Thifhelimbilu, Portia
- Date: 2013
- Subjects: Sewage sludge , Phosphorous
- Type: Article
- Identifier: uj:4855 , http://hdl.handle.net/10210/12531
- Description: Sewage sludge from ERWAT (East Rand Water Care Company) was investigated to determine its potential as a source of P. The raw sewage sludge was found to be a potential source of P. At least 84% P could be leached from the raw sewage sludge after 60 min using either HCl or H2SO4. Selective precipitation of P as magnesium tetraphosphate could be achieved using ammonia and magnesium oxide to give yield a 92.2% pure magnesium tetraphosphate and 9.8% P.
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Treatment of acid mine drainage using un-activated bentonite and limestone
- Nkonyane, Thembelihle, Ntuli, Freeman, Muzenda, Edison
- Authors: Nkonyane, Thembelihle , Ntuli, Freeman , Muzenda, Edison
- Date: 2012
- Subjects: Acid mine drainage , Bentonite , Limestone , Heavy metal removal
- Type: Article
- Identifier: uj:6045 , ISSN 2010-3778 , http://hdl.handle.net/10210/10453
- Description: Please refer to full text to view abstract
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- Authors: Nkonyane, Thembelihle , Ntuli, Freeman , Muzenda, Edison
- Date: 2012
- Subjects: Acid mine drainage , Bentonite , Limestone , Heavy metal removal
- Type: Article
- Identifier: uj:6045 , ISSN 2010-3778 , http://hdl.handle.net/10210/10453
- Description: Please refer to full text to view abstract
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Purification of platinum metal refinery crystalliser effluent using ion-exchange
- Nheta, Willie, Ntuli, Freeman, Mulaba-Bafubiandi, Antoine F., Makhatha, Elizabeth
- Authors: Nheta, Willie , Ntuli, Freeman , Mulaba-Bafubiandi, Antoine F. , Makhatha, Elizabeth
- Date: 2014
- Subjects: Ion exchange , Impala Platinum Metal Refinery , Crystallised salts
- Type: Article
- Identifier: uj:4796 , http://hdl.handle.net/10210/12048
- Description: Impala Platinum Metal Refinery (PMR) produces about 30 tonnes of salt every month after crystallisation of effluent from the refining processes. These crystallised salts contain impurities (heavy metals) and are discarded. This poses a danger to the environment and it costs the company large amount money to correctly dump them. There is need to find ways of purifying these salts and find its alternative industrial uses. Major sectors identified using industrial salt were paper mills, pharmaceutical, textile, tanning and paint industrial sectors (Department of Minerals and Energy, 2001). Comparison of the salt composition with salt specifications required for these uses revealed that the salt needed further purification in order to find application in these industrial sectors. Two approaches were proposed; treatment of the crystallized salt to remove impurities and treatment of the crystallizer influent stream before crystallization to ensure a more pure salt is produced...
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- Authors: Nheta, Willie , Ntuli, Freeman , Mulaba-Bafubiandi, Antoine F. , Makhatha, Elizabeth
- Date: 2014
- Subjects: Ion exchange , Impala Platinum Metal Refinery , Crystallised salts
- Type: Article
- Identifier: uj:4796 , http://hdl.handle.net/10210/12048
- Description: Impala Platinum Metal Refinery (PMR) produces about 30 tonnes of salt every month after crystallisation of effluent from the refining processes. These crystallised salts contain impurities (heavy metals) and are discarded. This poses a danger to the environment and it costs the company large amount money to correctly dump them. There is need to find ways of purifying these salts and find its alternative industrial uses. Major sectors identified using industrial salt were paper mills, pharmaceutical, textile, tanning and paint industrial sectors (Department of Minerals and Energy, 2001). Comparison of the salt composition with salt specifications required for these uses revealed that the salt needed further purification in order to find application in these industrial sectors. Two approaches were proposed; treatment of the crystallized salt to remove impurities and treatment of the crystallizer influent stream before crystallization to ensure a more pure salt is produced...
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The removal of Ni, Cu & Fe from a mixed metal system using sodium hypophosphite as a reducing agent
- Ngema, Promise Sethembiso, Ntuli, Freeman, Belaid, Mohamed
- Authors: Ngema, Promise Sethembiso , Ntuli, Freeman , Belaid, Mohamed
- Date: 2012
- Subjects: Waste water treatment , Heavy metals , Sodium hypophosphite
- Type: Article
- Identifier: uj:4702 , http://hdl.handle.net/10210/10942
- Description: Please refer to full text to view abstract
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- Authors: Ngema, Promise Sethembiso , Ntuli, Freeman , Belaid, Mohamed
- Date: 2012
- Subjects: Waste water treatment , Heavy metals , Sodium hypophosphite
- Type: Article
- Identifier: uj:4702 , http://hdl.handle.net/10210/10942
- Description: Please refer to full text to view abstract
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Process intensification of zinc oxide leaching process using sulphuric acid
- Napo, P., Ntuli, Freeman, Muzenda, Edison, Mollagee, Mansoor
- Authors: Napo, P. , Ntuli, Freeman , Muzenda, Edison , Mollagee, Mansoor
- Date: 2011
- Subjects: Leaching , Zinc oxide ores
- Type: Article
- Identifier: uj:4705 , ISSN 2078-0966 , http://hdl.handle.net/10210/10948
- Description: This study investigated methods of intensifying the leaching of zinc oxide ore using sulphuric acid for the improvement of zinc recovery. The factors that were investigated in this study were agitation speed, acid concentration and the feeding mechanism of reactants into the reactor (batch and semi-batch processes). Analysis of the elemental composition of the ore was performed using XRF prior to leaching and an Atomic Absorption Spectrometer (AAS) was used to determine the amount of zinc recovered. The results obtained, showed that increasing the acid concentration results in a significant increase zinc recovery...
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- Authors: Napo, P. , Ntuli, Freeman , Muzenda, Edison , Mollagee, Mansoor
- Date: 2011
- Subjects: Leaching , Zinc oxide ores
- Type: Article
- Identifier: uj:4705 , ISSN 2078-0966 , http://hdl.handle.net/10210/10948
- Description: This study investigated methods of intensifying the leaching of zinc oxide ore using sulphuric acid for the improvement of zinc recovery. The factors that were investigated in this study were agitation speed, acid concentration and the feeding mechanism of reactants into the reactor (batch and semi-batch processes). Analysis of the elemental composition of the ore was performed using XRF prior to leaching and an Atomic Absorption Spectrometer (AAS) was used to determine the amount of zinc recovered. The results obtained, showed that increasing the acid concentration results in a significant increase zinc recovery...
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Temperature effect on volatile organic compounds – polydimethylsiloxane Interactions
- Muzenda, Edison, Ntuli, Freeman
- Authors: Muzenda, Edison , Ntuli, Freeman
- Date: 2011
- Subjects: Waste gas streams , Volatile organic compounds , Polydimethysiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:2179 , ISSN 2010-0221 , http://hdl.handle.net/10210/4559
- Description: Temperature dependence of specific retention volumes (og V) of 13 volatile organic compounds (VOCs) of environmental importance between the gas and liquid stationary phase (polydimethysiloxane) (PDMS) were studied using the gas liquid chromatographic technique (GLC). Temperature was varied from 303.15K to 423.15K to allow transport calculations for different seasons. Four PDMS polymers with average molecular weight ranging from 760 to 13 000 were used as solvents. The results of this work confirm that PDMS is well suited for VOCs scrubbing from waste gas streams. Linear plots of log g V against T1 were obtained in all cases permitting predictions and interpolations to temperatures not studied here. Also dependable enthalpies and entropies of solute transfer from the mobile phase to the stationary phase can be calculated. The specific retention volumes reported in this work are in agreement with literature for similar systems. Efforts were taken to ensure the best possible accuracy and trace the possible sources of error. A gas liquid chromatographic system which secured a simple retention mechanism and showed reproducible solute retention over a long period of time was devised.
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- Authors: Muzenda, Edison , Ntuli, Freeman
- Date: 2011
- Subjects: Waste gas streams , Volatile organic compounds , Polydimethysiloxane , Gas liquid chromatography
- Type: Article
- Identifier: uj:2179 , ISSN 2010-0221 , http://hdl.handle.net/10210/4559
- Description: Temperature dependence of specific retention volumes (og V) of 13 volatile organic compounds (VOCs) of environmental importance between the gas and liquid stationary phase (polydimethysiloxane) (PDMS) were studied using the gas liquid chromatographic technique (GLC). Temperature was varied from 303.15K to 423.15K to allow transport calculations for different seasons. Four PDMS polymers with average molecular weight ranging from 760 to 13 000 were used as solvents. The results of this work confirm that PDMS is well suited for VOCs scrubbing from waste gas streams. Linear plots of log g V against T1 were obtained in all cases permitting predictions and interpolations to temperatures not studied here. Also dependable enthalpies and entropies of solute transfer from the mobile phase to the stationary phase can be calculated. The specific retention volumes reported in this work are in agreement with literature for similar systems. Efforts were taken to ensure the best possible accuracy and trace the possible sources of error. A gas liquid chromatographic system which secured a simple retention mechanism and showed reproducible solute retention over a long period of time was devised.
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An investigation into the effect of temperature on the leaching of copper-matte
- Muzenda, Edison, Ramatsa, I.M., Ntuli, Freeman, Belaid, Mohamed, Tshwabi, P.M.
- Authors: Muzenda, Edison , Ramatsa, I.M. , Ntuli, Freeman , Belaid, Mohamed , Tshwabi, P.M.
- Date: 2011
- Subjects: Coppermatte leaching - Effect of temperature , Leaching - Effect of temperature
- Type: Article
- Identifier: uj:4703 , http://hdl.handle.net/10210/10944
- Description: A study was carried out to determine the influence of the temperature and the reaction involved on the leaching of coppermatte. Copper (Cu) bearing matte from Impala Refinery (Pty) Ltd was used in the investigation. The experiments were conducted in a leaching cell submerged in a water bath, with ammonia concentrations (leaching solution) of 3.0M, temperature of 50°C, 60°C and 70°C, pH of 11 and for a time period of 130 minutes. Leaching tests indicated that Cu recovery increased in the temperature range 50°C - 60°C, however at a temperature of 70°C Cu recovery decreases because of cementation process as nickel displace copper. The shrinking core model was used to determine if the leaching process was diffusion controlled, or chemical controlled, or even mixed controlled. It was found that the leaching process could not be determined using the shrinking core model due to the cementation process of Cu. It was concluded that an increase in temperature results in an increase in the Cu recovery however the temperature should not be too high as cementation process increase with increasing temperature.
- Full Text:
- Authors: Muzenda, Edison , Ramatsa, I.M. , Ntuli, Freeman , Belaid, Mohamed , Tshwabi, P.M.
- Date: 2011
- Subjects: Coppermatte leaching - Effect of temperature , Leaching - Effect of temperature
- Type: Article
- Identifier: uj:4703 , http://hdl.handle.net/10210/10944
- Description: A study was carried out to determine the influence of the temperature and the reaction involved on the leaching of coppermatte. Copper (Cu) bearing matte from Impala Refinery (Pty) Ltd was used in the investigation. The experiments were conducted in a leaching cell submerged in a water bath, with ammonia concentrations (leaching solution) of 3.0M, temperature of 50°C, 60°C and 70°C, pH of 11 and for a time period of 130 minutes. Leaching tests indicated that Cu recovery increased in the temperature range 50°C - 60°C, however at a temperature of 70°C Cu recovery decreases because of cementation process as nickel displace copper. The shrinking core model was used to determine if the leaching process was diffusion controlled, or chemical controlled, or even mixed controlled. It was found that the leaching process could not be determined using the shrinking core model due to the cementation process of Cu. It was concluded that an increase in temperature results in an increase in the Cu recovery however the temperature should not be too high as cementation process increase with increasing temperature.
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Kinetics study of ammonia removal from synthetic waste water
- Muzenda, Edison, Kabuba, John, Ntuli, Freeman, Mollagee, Mansoor
- Authors: Muzenda, Edison , Kabuba, John , Ntuli, Freeman , Mollagee, Mansoor
- Date: 2011
- Subjects: Ammonium exchange , Langmuir isotherm , Clinoptilolite , Synthetic waste water
- Type: Article
- Identifier: uj:4698 , http://hdl.handle.net/10210/10933
- Description: The aim of this study was to investigate ammonium exchange capacity of natural and activated clinoptilolite from Kwazulu-Natal Province, South Africa. X-ray fluorescence (XRF) analysis showed that the clinoptilolite contained exchangeable ions of sodium, potassium, calcium and magnesium. This analysis also confirmed that the zeolite sample had a high silicon composition compared to aluminium. Batch equilibrium studies were performed in an orbital shaker and the data fitted the Langmuir isotherm very well. The ammonium exchange capacity was found to increase with pH and temperature. Clinoptilolite functionalization with hydrochloric acid increased its ammonia uptake ability.
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- Authors: Muzenda, Edison , Kabuba, John , Ntuli, Freeman , Mollagee, Mansoor
- Date: 2011
- Subjects: Ammonium exchange , Langmuir isotherm , Clinoptilolite , Synthetic waste water
- Type: Article
- Identifier: uj:4698 , http://hdl.handle.net/10210/10933
- Description: The aim of this study was to investigate ammonium exchange capacity of natural and activated clinoptilolite from Kwazulu-Natal Province, South Africa. X-ray fluorescence (XRF) analysis showed that the clinoptilolite contained exchangeable ions of sodium, potassium, calcium and magnesium. This analysis also confirmed that the zeolite sample had a high silicon composition compared to aluminium. Batch equilibrium studies were performed in an orbital shaker and the data fitted the Langmuir isotherm very well. The ammonium exchange capacity was found to increase with pH and temperature. Clinoptilolite functionalization with hydrochloric acid increased its ammonia uptake ability.
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Effect of pH on the recovery and grade of base metal sulphides (PGMs) by flotation
- Muzenda, Edison, Afolabi, Ayo S., Abdulkareem, Ambali S., Ntuli, Freeman
- Authors: Muzenda, Edison , Afolabi, Ayo S. , Abdulkareem, Ambali S. , Ntuli, Freeman
- Date: 2011
- Subjects: Platinum Group Metals , Metal sulphides , Flotation
- Type: Article
- Identifier: uj:4713 , ISSN 2078-0966 , http://hdl.handle.net/10210/10959
- Description: This study investigated the effect of pH on the recovery and grade of the Platinum Group Metals (PGMs) and base metal sulphides from the UG2 ore of the Bushveld Complex. This was achieved through running a series of test work in a Denver flotation cell at varying pH 6-11 at constant reagent dosage. The UG-2 reef is characterized by two predominant gangue phases i.e. chromite and silicate, that have significantly different physical and chemical properties. The test work was aimed at evaluating which pH gives best recoveries, and finding the effect of the chrome content in these recoveries. A pH of 9 gave the highest recovery compared to other pH ranges. However, the highest PGM grade was attained at a pH of 6 which is slightly acidic. Ideally this trend could be expected since the collectors (xanthates) are more stable in alkaline medium. The higher PGM recovery was also accompanied by higher chrome content as a result of their similar chemical properties.
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- Authors: Muzenda, Edison , Afolabi, Ayo S. , Abdulkareem, Ambali S. , Ntuli, Freeman
- Date: 2011
- Subjects: Platinum Group Metals , Metal sulphides , Flotation
- Type: Article
- Identifier: uj:4713 , ISSN 2078-0966 , http://hdl.handle.net/10210/10959
- Description: This study investigated the effect of pH on the recovery and grade of the Platinum Group Metals (PGMs) and base metal sulphides from the UG2 ore of the Bushveld Complex. This was achieved through running a series of test work in a Denver flotation cell at varying pH 6-11 at constant reagent dosage. The UG-2 reef is characterized by two predominant gangue phases i.e. chromite and silicate, that have significantly different physical and chemical properties. The test work was aimed at evaluating which pH gives best recoveries, and finding the effect of the chrome content in these recoveries. A pH of 9 gave the highest recovery compared to other pH ranges. However, the highest PGM grade was attained at a pH of 6 which is slightly acidic. Ideally this trend could be expected since the collectors (xanthates) are more stable in alkaline medium. The higher PGM recovery was also accompanied by higher chrome content as a result of their similar chemical properties.
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Waste management, strategies and situation in South Africa : an overview
- Muzenda, Edison, Ntuli, Freeman, Pilusa, Tsietsi Jefrey
- Authors: Muzenda, Edison , Ntuli, Freeman , Pilusa, Tsietsi Jefrey
- Date: 2012
- Subjects: Waste management - South Africa , Refuse disposal - South Africa
- Type: Article
- Identifier: uj:6044 , ISBN 2010-376X , http://hdl.handle.net/10210/10452
- Description: This paper highlights some interesting facts on South African’s waste situation and management strategies, in particular the Integrated Waste Management. South Africa supports a waste hierarchy by promoting cleaner production, waste minimisation, reuse, recycling and waste treatment with disposal and remediation as the last preferred options in waste management. The drivers for waste management techniques are identified as increased demand for waste service provision; increased demand for waste minimisation; recycling and recovery; land use, physical and environmental limitations; and socio-economic and demographic factors. The South African government recognizes the importance of scientific research as outlined on the white paper on Integrated Pollution and Waste Management (IP and WM) (DEAT, 2000).
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- Authors: Muzenda, Edison , Ntuli, Freeman , Pilusa, Tsietsi Jefrey
- Date: 2012
- Subjects: Waste management - South Africa , Refuse disposal - South Africa
- Type: Article
- Identifier: uj:6044 , ISBN 2010-376X , http://hdl.handle.net/10210/10452
- Description: This paper highlights some interesting facts on South African’s waste situation and management strategies, in particular the Integrated Waste Management. South Africa supports a waste hierarchy by promoting cleaner production, waste minimisation, reuse, recycling and waste treatment with disposal and remediation as the last preferred options in waste management. The drivers for waste management techniques are identified as increased demand for waste service provision; increased demand for waste minimisation; recycling and recovery; land use, physical and environmental limitations; and socio-economic and demographic factors. The South African government recognizes the importance of scientific research as outlined on the white paper on Integrated Pollution and Waste Management (IP and WM) (DEAT, 2000).
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