A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality

Ronald Ngulube; Kennedy Nakena Katundu; Kenny Nyirenda; Anthony Siakamba

doi:doi:10.11648/j.ajep.20160504.13

| Peer-Reviewed

A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality

Ronald Ngulube, Kennedy Nakena Katundu, Kenny Nyirenda, Anthony Siakamba

Published in American Journal of Environmental Protection (Volume 5, Issue 4)

Received: 3 June 2016 Accepted: 21 June 2016 Published: 6 July 2016

Views: Downloads:

Download PDF

Share This Article

Twitter
Linked In
Facebook

Abstract

The Nchanga tailings dam, a reservoir of mine waste from Konkola Copper Mines (KCM) operations in Zambia, discharges its effluent into the local Muntimpa stream. The Muntimpa stream, a possible source of drinking and domestic water for the local population, flows into Mwambashi stream which subsequently discharges into Kafue river. The Kafue river is a significant support of economic development in Zambia and is a source of 40% of drinking water for the cities with about 50% of the population living in the catchment. This study looks at an overview of the operations of Nchanga tailings dam and assesses the levels of pH, TSS, TDS, Cu, Mn, Co and SO4 in the effluent discharged in rainy and dry seasons. It also provides possible methods that could be used to lower pollutant levels to below recommended Zambia Environmental Management Agency (ZEMA) limits. To determine the pollutant concentrations, sixty (60) samples were collected from the tailings dam spillway in rainy season (April) and dry season (October) of 2015 and analysed on a daily basis. The results indicated that the average pH, TSS and Cu levels in the samples from both wet and dry seasons were within the permissible range of 6.0-9.0, below 100 mg/l and 1.0 mg/l respectively. The TDS average figure (2658±331 mg/l) recorded in April was less than the allowable limit while significantly higher value (4783±86.6 mg/l) was obtained in October. The concentrations of Mn and Co were significantly high and above ZEMA limits with mean values of 79±22.1 mg/l and 11±5.9 mg/l for rainy season and 189±19.2 mg/l and 19±1.3 mg/l for dry season respectively. The SO4 content was observed to be high in both seasons with average figures of 2071±240 mg/l in April and 3628±261 mg/l in October. It was observed that the levels of all the parameters analysed (with exception of Cu) showed seasonal variations attributed to evaporative effects. To minimise contaminants levels in the effluent, it is recommended that the discharged effluent should be restricted in dry season until the levels of dissolved pollutants are sufficiently low in wet season. Recycling of water from the decantation pond of the tailings impoundment back to the main plant is an effective alternative that would eliminate pollution of water bodies. Other methods that could be employed involve the use of chemical and biological treatment technologies.

Published in	American Journal of Environmental Protection (Volume 5, Issue 4)
DOI	10.11648/j.ajep.20160504.13
Page(s)	90-96
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2016. Published by Science Publishing Group

Keywords

Nchanga Tailings Dam, Muntimpa Stream, Mwambashi Stream, Effluent Quality

References

[1]	L. Norrgren, U. Pettersson, S. Orn, P. Bergqvist. (2000). Environmental monitoring of the Kafue River, located in the Copperbelt, Zambia. Archives of Environmental Contamination and Toxicology. [Online] 38. pp. 334-341. Available: http://www.ncbi.nlm.nih.gov/pubmed/10667931
[2]	U. T. Pettersson, J. Ingri, P. S. Andersson. (2000). Hydrogeochemical processes in the Kafue River upstream from the Copperbelt mining area, Zambia. Aquatic Geochemistry. [Online] 6. pp. 385-411. Available: http://www.ncbi.nlm.nih.gov/pubmed/10667931
[3]	Environmental Council of Zambia, “Zambia Environment Outlook 3,” 2008.
[4]	K. Fytas, J. Hadjigeorgiou. (1994). An assessment of acid rock drainage continuous monitoring technology. Enviromental Geology. [Online] 1. pp. 33-40. Available: http://link.springer.com/article/10.1007%2FBF01061828#page-1
[5]	K. Vanderlinden, R. Ordonez, M. J. Polo, J. V. Giraldez. (2006). Mapping residual pyrite after a mine spill using non co-located spatiotemporal observations. Journal Environment Quality. [Online] 35. pp. 21-36. Available: http://www.ncbi.nlm.nih.gov/pubmed/16391274
[6]	K. Burnod-Requia, “Rapid environmental assessment of the Tisza river basin,” United Nations Environment Programme, 2004.
[7]	C. Kraft, W. Tumpling, D. W. Zachmann. (2006). The effects of mining in Northern Romania on the heavy metal distribution in sediments of the rivers Szamos and Tisza (Hungary). Acta hidrochim.hydrobiol. [Online] 34. pp. 257-264. Available: http://onlinelibrary.wiley.com/doi/10.1002/aheh.200400622/abstract
[8]	S. Mwale, "Zambia: Kitwe, Kalulushi Water Plants to Reopen-NWSC," Times of Zambia, pp. 15, 30 November 2013 Available: http://allafrica.com/stories/201312010115.html
[9]	M. A. Acheampong, R. J. Meulepas, P. N. Lens. (2010). Removal of heavy metals and cyanide from gold mine wastewater. Journal of Chemical Technology & Biotechnology. [Online] 85. pp. 590-613. Available: http://onlinelibrary.wiley.com/doi/10.1002/jctb.2358/full
[10]	Konkola Copper Mines Plc, “Tailings Leach Plant Internal Technical Reports’ 2011.
[11]	D. A. Skoog and D. M. West, Fundamentals of Analytical Chemistry. 3rd Ed. Holt, Rinehart and Winston, New York. pp. 296-298, 505-508.
[12]	R. W. Lawrence, P. B. Marchant, M. Bratty, D. Ratochvil, “Applications for biogenic sulphide reagent for copper recovery in copper and gold hydrometallurgical operations”, Proc. Cu 2007, the 6th Copper/Cobre Conference, August 25-30, 2007, Toronto, Canada, 2007.
[13]	J. S. Hadzi, M. Maletić, A. Dimitrov, D. Slavkov, P. Paunović, “Desalination”, 1-7. 2006.
[14]	N. Papassiopi, E. Mylona, A. Xenidis, I. Paspaliaris. Scientific Committee of Mining and Metallurgical Engineers, Vol. A. 2000.
[15]	J. Singh, S. K. Upadhyay, R. K. Pathak, V. Gupta. (2011). Accumulation of heavy metals in soil and paddy crop (Oryza sativa), irrigated with water of Ramgarh Lake, Gorakhpur, UP, India. Toxicol. Environ. Chem. [Online] 93 (3) pp. 462-473.
[16]	W. D. Heizer, R. S. Sandler, E. Seal, S. C. Murray, M. G. Busby, B. G. Schliebe, S. N. Pusek. (1997). Intestinal Effects of Sulfate in Drinking Water on Normal Human Subjects. Digestive Diseases and Sciences. [Online] 44 pp. 1055-1061. Availvable: http://link.springer.com/article/10.1023%2FA%3A1018801522760.
[17]	J. Smuda, B. Dold, J. E. Spangenberg, K. Friese, M. R. Kobek, C. A. Bustos, H. R. Pfeifer. (2014). Element cycling during the transition from alkaline to acidic environment in an active porphyry copper tailings impoundment, Chuquicamata, Chile. Journal of Geochemical Exploration. [Online] 140. pp. 23–40. Available: http://www.sciencedirect.com/science/article/pii/S0375674214000156
[18]	B. Dold, N. Diaby, J. E. Spangenberg. (2011). Remediation of a marine shore tailings deposit and the importance of water-rock interaction on element cycling in the coastal aquifer. Environ. Sci. Technol. [Online] 45. pp. 4876–4883. Available: http://www.ncbi.nlm.nih.gov/pubmed/21563818
[19]	B. Dold. (2014). Evolution of Acid Mine Drainage Formation in Sulphidic. Minerals. [Online] 14. pp. 621-641. Available: http://www.mdpi.com/2075-163X/4/3/621
[20]	R. W. Lawrence, D. Kratochvil, D. Ramey, “A new commercial metal recovery technology utilizing on-site biological H2S production”, Proc. HydroCopper -3rdInternational Workshop on Copper Hydrometallurgy. Santiago, Chile, November 23-25. 2005.
[21]	M. Bratty, R. W. Lawrence, D. Kratochvil, “Reducing water treatment costs while meeting the challenge of environmental compliance for the mining industry”, Proc. WIM 2008-1st International Congress on Water Management in the Mining Industry. Santiago, Chile, July 9-11, 2008.
[22]	B. Aubé, B. Arseneault, “In-Pit Mine Drainage Treatment System in a Northern Climate”, In Proceedings for Sudbury 2003 Mining and the Environment Conference, May 25-28 2003. Available: http://www.enviraube.com/images/raglan.pdf
[23]	A. J. Geldenhuys, J. P. Maree, M. de Beer, P. Hlabela, “An Integrated limestone lime process for partial sulphate removal”, Paper presented at the conference on Environmentally Responsible Mining in South Africa, Sept 2001.
[24]	M. Bratty, R. W. Lawrence, D. Kratochvil, P. B. Marchant, “Applications of biological H2S production from elemental sulphur in the treatment of heavy metal pollution including acid rock drainage”, Proc. International Symposium on Acid Rock Drainage (ICARD), St. Louis, March 26, 29, 2006.
[25]	R. D. Ludwig, R. G. McGregor, D. W. Blowes, S. G. Benner, K. Mountjoy. (2002). A peamable reactive barrier for treatment of heavy metals. Ground Water 40: 59-66.
[26]	Meeting challenges of heavy metal pollution in aqueous solutions. Current science, 78 (8): 967-973.
[27]	G. C. Miller, T. K. Tsukamoto. (2002). Remediation of Zinc at the Equity Silver Mine Unpublished Report Placer Dome, Canada.
[28]	K. Alexander, S. Alt, E. Owens, M. Patel, L. McGovern, “Low fouling reverse osmosis membranes evidence to the contrary on microfiltered secondary effluent”, Proc. AWWA Memb. Technology Conference, 2003.
[29]	R. Faryal, A. Hameed A (2005). Isolation and characterization of various fungal strains from textile effluent for their use in bioremediation. Pakistani Journal of Botany, 37 (4): 1003-1008.
[30]	M. A. Dias, I. C. A. Lacerda, P. F. Pimentel, H. F. Castro, C. A. Rosa. (2002). Removal of heavy metals by an Aspergillus terreus strain immobilized in a polyurethane matrix. Letters in Applied Microbiology, 34: 46-50.
[31]	P. Rajendran, J. Muthukristnan, P. Gunasekaran. (2003). Microbes in heavy metal remediation. Indian Journal of Experimental Biology, 41: 935-944.
[32]	K. Ramasamy B. Kamaludeen, P. B. Sara. (2006). Bioremediation of Metals: Microbial
[33]	P. G. Ana, O. S. Antonio, M. L. Paula. (2009). Remediation of heavy metal contaminated soils: phytoremediation as a potentially promising clean-up Technology. Journal of Environmental Science and Technology, 39 (1): 622–654
[34]	M. Bratty, R. Lawrence, D. Kratochvil, B. Marchant, “Applications of Biological H2S Production from Elemental Sulfur in the Treatment of Heavy Metal Pollution Including Acid Rock Drainage”, 7th ICARD ‘Leadership: Gateway to the Future, 2006.
[35]	O. B. Akpor, M. Muchie. (2010). Remediation of heavy metals in drinking water and wastewater treatment systems: Processes and applications. International Journal of the Physical Sciences. [Online] 5 (12). pp. 1807-1817. Available: http://www.academicjournals.org/article/article1380814369_Akpor%20and%20Muchie.pdf
[36]	O. B. Akpor, G. O. Ohiobor, T. D. Olaolu. (2010). Heavy Metal Pollutants in Wastewater Effluents: Sources, Effects and Remediation. Advances in Bioscience and Bioengineering. Vol. 2, No. 4, pp. 37-43.

Cite This Article

Plain Text BibTeX RIS

APA Style

Ronald Ngulube, Kennedy Nakena Katundu, Kenny Nyirenda, Anthony Siakamba. (2016). A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. American Journal of Environmental Protection, 5(4), 90-96. https://doi.org/10.11648/j.ajep.20160504.13

Copy | Download

ACS Style

Ronald Ngulube; Kennedy Nakena Katundu; Kenny Nyirenda; Anthony Siakamba. A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. Am. J. Environ. Prot. 2016, 5(4), 90-96. doi: 10.11648/j.ajep.20160504.13

Copy | Download

AMA Style

Ronald Ngulube, Kennedy Nakena Katundu, Kenny Nyirenda, Anthony Siakamba. A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. Am J Environ Prot. 2016;5(4):90-96. doi: 10.11648/j.ajep.20160504.13

Copy | Download

@article{10.11648/j.ajep.20160504.13,
  author = {Ronald Ngulube and Kennedy Nakena Katundu and Kenny Nyirenda and Anthony Siakamba},
  title = {A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality},
  journal = {American Journal of Environmental Protection},
  volume = {5},
  number = {4},
  pages = {90-96},
  doi = {10.11648/j.ajep.20160504.13},
  url = {https://doi.org/10.11648/j.ajep.20160504.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajep.20160504.13},
  abstract = {The Nchanga tailings dam, a reservoir of mine waste from Konkola Copper Mines (KCM) operations in Zambia, discharges its effluent into the local Muntimpa stream. The Muntimpa stream, a possible source of drinking and domestic water for the local population, flows into Mwambashi stream which subsequently discharges into Kafue river. The Kafue river is a significant support of economic development in Zambia and is a source of 40% of drinking water for the cities with about 50% of the population living in the catchment. This study looks at an overview of the operations of Nchanga tailings dam and assesses the levels of pH, TSS, TDS, Cu, Mn, Co and SO4 in the effluent discharged in rainy and dry seasons. It also provides possible methods that could be used to lower pollutant levels to below recommended Zambia Environmental Management Agency (ZEMA) limits. To determine the pollutant concentrations, sixty (60) samples were collected from the tailings dam spillway in rainy season (April) and dry season (October) of 2015 and analysed on a daily basis. The results indicated that the average pH, TSS and Cu levels in the samples from both wet and dry seasons were within the permissible range of 6.0-9.0, below 100 mg/l and 1.0 mg/l respectively. The TDS average figure (2658±331 mg/l) recorded in April was less than the allowable limit while significantly higher value (4783±86.6 mg/l) was obtained in October. The concentrations of Mn and Co were significantly high and above ZEMA limits with mean values of 79±22.1 mg/l and 11±5.9 mg/l for rainy season and 189±19.2 mg/l and 19±1.3 mg/l for dry season respectively. The SO4 content was observed to be high in both seasons with average figures of 2071±240 mg/l in April and 3628±261 mg/l in October. It was observed that the levels of all the parameters analysed (with exception of Cu) showed seasonal variations attributed to evaporative effects. To minimise contaminants levels in the effluent, it is recommended that the discharged effluent should be restricted in dry season until the levels of dissolved pollutants are sufficiently low in wet season. Recycling of water from the decantation pond of the tailings impoundment back to the main plant is an effective alternative that would eliminate pollution of water bodies. Other methods that could be employed involve the use of chemical and biological treatment technologies.},
 year = {2016}
}

Copy | Download

TY  - JOUR
T1  - A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality
AU  - Ronald Ngulube
AU  - Kennedy Nakena Katundu
AU  - Kenny Nyirenda
AU  - Anthony Siakamba
Y1  - 2016/07/06
PY  - 2016
N1  - https://doi.org/10.11648/j.ajep.20160504.13
DO  - 10.11648/j.ajep.20160504.13
T2  - American Journal of Environmental Protection
JF  - American Journal of Environmental Protection
JO  - American Journal of Environmental Protection
SP  - 90
EP  - 96
PB  - Science Publishing Group
SN  - 2328-5699
UR  - https://doi.org/10.11648/j.ajep.20160504.13
AB  - The Nchanga tailings dam, a reservoir of mine waste from Konkola Copper Mines (KCM) operations in Zambia, discharges its effluent into the local Muntimpa stream. The Muntimpa stream, a possible source of drinking and domestic water for the local population, flows into Mwambashi stream which subsequently discharges into Kafue river. The Kafue river is a significant support of economic development in Zambia and is a source of 40% of drinking water for the cities with about 50% of the population living in the catchment. This study looks at an overview of the operations of Nchanga tailings dam and assesses the levels of pH, TSS, TDS, Cu, Mn, Co and SO4 in the effluent discharged in rainy and dry seasons. It also provides possible methods that could be used to lower pollutant levels to below recommended Zambia Environmental Management Agency (ZEMA) limits. To determine the pollutant concentrations, sixty (60) samples were collected from the tailings dam spillway in rainy season (April) and dry season (October) of 2015 and analysed on a daily basis. The results indicated that the average pH, TSS and Cu levels in the samples from both wet and dry seasons were within the permissible range of 6.0-9.0, below 100 mg/l and 1.0 mg/l respectively. The TDS average figure (2658±331 mg/l) recorded in April was less than the allowable limit while significantly higher value (4783±86.6 mg/l) was obtained in October. The concentrations of Mn and Co were significantly high and above ZEMA limits with mean values of 79±22.1 mg/l and 11±5.9 mg/l for rainy season and 189±19.2 mg/l and 19±1.3 mg/l for dry season respectively. The SO4 content was observed to be high in both seasons with average figures of 2071±240 mg/l in April and 3628±261 mg/l in October. It was observed that the levels of all the parameters analysed (with exception of Cu) showed seasonal variations attributed to evaporative effects. To minimise contaminants levels in the effluent, it is recommended that the discharged effluent should be restricted in dry season until the levels of dissolved pollutants are sufficiently low in wet season. Recycling of water from the decantation pond of the tailings impoundment back to the main plant is an effective alternative that would eliminate pollution of water bodies. Other methods that could be employed involve the use of chemical and biological treatment technologies.
VL  - 5
IS  - 4
ER  -

Copy | Download

Author Information

Ronald Ngulube

Department of Chemical Engineering, Copperbelt University, Kitwe, Zambia
Kennedy Nakena Katundu

Department of Chemical Engineering, Copperbelt University, Kitwe, Zambia
Kenny Nyirenda

Department of Geology and Survey, Copperbelt University, Kitwe, Zambia
Anthony Siakamba

Tailings Leach Plant, Nchanga IBU, Konkola Copper Mines Plc, Chingola Zambia

Download PDF

Sections

Plain Text BibTeX RIS

APA Style

Ronald Ngulube, Kennedy Nakena Katundu, Kenny Nyirenda, Anthony Siakamba. (2016). A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. American Journal of Environmental Protection, 5(4), 90-96. https://doi.org/10.11648/j.ajep.20160504.13

Copy | Download

ACS Style

Ronald Ngulube; Kennedy Nakena Katundu; Kenny Nyirenda; Anthony Siakamba. A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. Am. J. Environ. Prot. 2016, 5(4), 90-96. doi: 10.11648/j.ajep.20160504.13

Copy | Download

AMA Style

Ronald Ngulube, Kennedy Nakena Katundu, Kenny Nyirenda, Anthony Siakamba. A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality. Am J Environ Prot. 2016;5(4):90-96. doi: 10.11648/j.ajep.20160504.13

Copy | Download

@article{10.11648/j.ajep.20160504.13,
  author = {Ronald Ngulube and Kennedy Nakena Katundu and Kenny Nyirenda and Anthony Siakamba},
  title = {A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality},
  journal = {American Journal of Environmental Protection},
  volume = {5},
  number = {4},
  pages = {90-96},
  doi = {10.11648/j.ajep.20160504.13},
  url = {https://doi.org/10.11648/j.ajep.20160504.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajep.20160504.13},
  abstract = {The Nchanga tailings dam, a reservoir of mine waste from Konkola Copper Mines (KCM) operations in Zambia, discharges its effluent into the local Muntimpa stream. The Muntimpa stream, a possible source of drinking and domestic water for the local population, flows into Mwambashi stream which subsequently discharges into Kafue river. The Kafue river is a significant support of economic development in Zambia and is a source of 40% of drinking water for the cities with about 50% of the population living in the catchment. This study looks at an overview of the operations of Nchanga tailings dam and assesses the levels of pH, TSS, TDS, Cu, Mn, Co and SO4 in the effluent discharged in rainy and dry seasons. It also provides possible methods that could be used to lower pollutant levels to below recommended Zambia Environmental Management Agency (ZEMA) limits. To determine the pollutant concentrations, sixty (60) samples were collected from the tailings dam spillway in rainy season (April) and dry season (October) of 2015 and analysed on a daily basis. The results indicated that the average pH, TSS and Cu levels in the samples from both wet and dry seasons were within the permissible range of 6.0-9.0, below 100 mg/l and 1.0 mg/l respectively. The TDS average figure (2658±331 mg/l) recorded in April was less than the allowable limit while significantly higher value (4783±86.6 mg/l) was obtained in October. The concentrations of Mn and Co were significantly high and above ZEMA limits with mean values of 79±22.1 mg/l and 11±5.9 mg/l for rainy season and 189±19.2 mg/l and 19±1.3 mg/l for dry season respectively. The SO4 content was observed to be high in both seasons with average figures of 2071±240 mg/l in April and 3628±261 mg/l in October. It was observed that the levels of all the parameters analysed (with exception of Cu) showed seasonal variations attributed to evaporative effects. To minimise contaminants levels in the effluent, it is recommended that the discharged effluent should be restricted in dry season until the levels of dissolved pollutants are sufficiently low in wet season. Recycling of water from the decantation pond of the tailings impoundment back to the main plant is an effective alternative that would eliminate pollution of water bodies. Other methods that could be employed involve the use of chemical and biological treatment technologies.},
 year = {2016}
}

Copy | Download

TY  - JOUR
T1  - A Review of Nchanga Tailings Dam Operations and Seasonal Assessment of Its Effluent Quality
AU  - Ronald Ngulube
AU  - Kennedy Nakena Katundu
AU  - Kenny Nyirenda
AU  - Anthony Siakamba
Y1  - 2016/07/06
PY  - 2016
N1  - https://doi.org/10.11648/j.ajep.20160504.13
DO  - 10.11648/j.ajep.20160504.13
T2  - American Journal of Environmental Protection
JF  - American Journal of Environmental Protection
JO  - American Journal of Environmental Protection
SP  - 90
EP  - 96
PB  - Science Publishing Group
SN  - 2328-5699
UR  - https://doi.org/10.11648/j.ajep.20160504.13
AB  - The Nchanga tailings dam, a reservoir of mine waste from Konkola Copper Mines (KCM) operations in Zambia, discharges its effluent into the local Muntimpa stream. The Muntimpa stream, a possible source of drinking and domestic water for the local population, flows into Mwambashi stream which subsequently discharges into Kafue river. The Kafue river is a significant support of economic development in Zambia and is a source of 40% of drinking water for the cities with about 50% of the population living in the catchment. This study looks at an overview of the operations of Nchanga tailings dam and assesses the levels of pH, TSS, TDS, Cu, Mn, Co and SO4 in the effluent discharged in rainy and dry seasons. It also provides possible methods that could be used to lower pollutant levels to below recommended Zambia Environmental Management Agency (ZEMA) limits. To determine the pollutant concentrations, sixty (60) samples were collected from the tailings dam spillway in rainy season (April) and dry season (October) of 2015 and analysed on a daily basis. The results indicated that the average pH, TSS and Cu levels in the samples from both wet and dry seasons were within the permissible range of 6.0-9.0, below 100 mg/l and 1.0 mg/l respectively. The TDS average figure (2658±331 mg/l) recorded in April was less than the allowable limit while significantly higher value (4783±86.6 mg/l) was obtained in October. The concentrations of Mn and Co were significantly high and above ZEMA limits with mean values of 79±22.1 mg/l and 11±5.9 mg/l for rainy season and 189±19.2 mg/l and 19±1.3 mg/l for dry season respectively. The SO4 content was observed to be high in both seasons with average figures of 2071±240 mg/l in April and 3628±261 mg/l in October. It was observed that the levels of all the parameters analysed (with exception of Cu) showed seasonal variations attributed to evaporative effects. To minimise contaminants levels in the effluent, it is recommended that the discharged effluent should be restricted in dry season until the levels of dissolved pollutants are sufficiently low in wet season. Recycling of water from the decantation pond of the tailings impoundment back to the main plant is an effective alternative that would eliminate pollution of water bodies. Other methods that could be employed involve the use of chemical and biological treatment technologies.
VL  - 5
IS  - 4
ER  -

Copy | Download