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Baieta R, Ettler V, Vaněk A, Drahota P, Kříbek B, Nyambe I, Mihaljevič M. Smelter-derived soil contamination in Luanshya, Zambia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161405. [PMID: 36621473 DOI: 10.1016/j.scitotenv.2023.161405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/18/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
Extensive mining and smelting contributed to the declining quality of Luanshya soils. The local smelter was the epicenter of contamination as shown by a spatial distribution analysis. Closeby soil profiles smelter exhibit extremely high Cu concentrations (up to 46,000 mg kg-1 Cu) relative to deeper layers where only background levels of trace elements were observed. A remote profile did not exhibit significant contamination. Lead isotopic ratios revealed that Pb contamination in the Luanshya soils was not smelter-derived. It was shown in this way that the historical usage of leaded gasoline was the main source of this metal. Although the Luanshya smelter also produced Co, this metal was not an important contaminant. Copper leaching was a concern in Luanshya. Upwards of 52 % of Cu was extractable in the exchangeable step of a sequential extraction procedure (SEP), but only for samples where Cu concentrations were high, suggesting that Cu was released exclusively from anthropogenic particles. This was supported by the SEP results for similar depths at the remote soil, where only a small fraction of Cu was labile (5.6 %). Lead and Co were strongly bound in the soils throughout. The excess of Cu in the topsoils was mostly bound in smelter-derived particles. These appeared as spherical fast-cooled droplets composed mostly of sulfides, oxides, and glass. X-ray diffraction and electron probe microanalysis of those particles allowed for a phase classification. Compositions were regularly not stoichiometric so most particles were classified as intermediate solid solutions. However, molecular proportions often closely resembled those of bornite, chalcanthite, cuprospinel, covellite, delafossite, diginite, or hydrous ferric oxides. Concentrations of Cu were often 100 % near the center of the particles indicating an inefficient smelting process. Weathering to some degree was common, which in conjunction with the susceptibility of Cu leaching was highly alarming.
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Affiliation(s)
- Rafael Baieta
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, CZ-128 43 Prague 2, Czech Republic.
| | - Vojtěch Ettler
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, CZ-128 43 Prague 2, Czech Republic
| | - Aleš Vaněk
- Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food, and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic
| | - Petr Drahota
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, CZ-128 43 Prague 2, Czech Republic
| | - Bohdan Kříbek
- Czech Geological Survey, Geologická 6, Prague 152 00 5, Czech Republic
| | - Imasiku Nyambe
- University of Zambia, School of Mines, Department of Geology, POB 32 379, Lusaka, Zambia
| | - Martin Mihaljevič
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, CZ-128 43 Prague 2, Czech Republic
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Ódri Á, Amaral Filho J, Smart M, Broadhurst J, Harrison STL, Petersen J, Harris C, Edraki M, Becker M. Sulfur and oxygen isotope constraints on sulfate sources and neutral rock drainage-related processes at a South African colliery. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 846:157178. [PMID: 35839900 DOI: 10.1016/j.scitotenv.2022.157178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 06/17/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Understanding the fundamental controls that govern the generation of mine drainage is essential for waste management strategies. Combining the isotopic composition of water (H and O) and dissolved sulfate (S and O) with hydrogeochemical measurements of surface and groundwater, microbial analysis, composition of sediments and precipitates, and geochemical modeling results in this study we discussed the processes that control mine water chemistry and identified the potential source(s) and possible mechanisms governing sulfate formation and transformation around a South African colliery. Compared to various South African water standards, water samples collected from the surroundings of a coal waste disposal facility had elevated Fe2+ (0.9 to 56.9 mg L-1), Ca (33.0 to 527.0 mg L-1), Mg (6.2 to 457.0 mg L-1), Mn (0.1 to 8.6 mg L-1) and SO4 (19.7 to 3440.8 mg L-1) and circumneutral pH. The pH conditions are mainly controlled by the release of H+ from pyrite oxidation and the subsequent dissolution of carbonates and aluminosilicate minerals. The phases predicted to precipitate by equilibrium calculation were green rusts, ferrihydrite, gypsum, ±epsomite. Low concentrations of deleterious metals in solution are due to their low abundance in the local host rocks, and their attenuation through adsorption onto secondary Fe precipitates and co-precipitation at the elevated pH values. The δ34S values of sulfate are enriched (-6.5 ‰ to +5.6 ‰) compared to that of pyrite sampled from the mine (mean -22.5 ‰) and overlap with that of the organic sulfur of coal from the region (-2.5 to +4.9 ‰). The presence of both sulfur reducing and oxidizing bacteria were detected in the collected sediment samples. Combined, the data are consistent with the dissolved sulfate in the sampled waters from the colliery being derived primarily from pyrite probably with the subordinate contribution of organic sulfur, followed by its partial removal through precipitation and microbially-induced reduction.
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Affiliation(s)
- Ágnes Ódri
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Juarez Amaral Filho
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa; Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Mariette Smart
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Jennifer Broadhurst
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Susan T L Harrison
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa; Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Jochen Petersen
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa; Hydrometallurgy Research Group, Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Chris Harris
- Department of Geological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
| | - Mansour Edraki
- Centre for Water in the Minerals Industry, Sustainable Minerals Institute, The University of Queensland, St Lucia, QLD 4072 Brisbane, Australia.
| | - Megan Becker
- Minerals to Metals Initiative (MtM), Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa; Centre for Minerals Research, Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South Africa.
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Aquatic Ecological Risk of Heavy-Metal Pollution Associated with Degraded Mining Landscapes of the Southern Africa River Basins: A Review. MINERALS 2022. [DOI: 10.3390/min12020225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Africa accounts for nearly 30% of the discovered world’s mineral reserves, with half of the world’s platinum group metals deposits, 36% of gold, and 20% of cobalt being in Southern Africa (SA). The intensification of heavy-metal production in the SA region has exacerbated negative human and environmental health impacts. In recent years, mining waste generated from industrial and artisanal mining has significantly affected the ecological integrity of SA aquatic ecosystems due to the accelerated introduction and deposition of heavy metals. However, the extent to which heavy-metal pollution associated with mining has impacted the aquatic ecosystems has not been adequately documented, particularly during bioassessments. This review explores the current aquatic ecological impacts on the heavily mined river basins of SA. It also discusses the approaches to assessing the ecological risks, inherent challenges, and potential for developing an integrated ecological risk assessment protocol for aquatic systems in the region. Progress has been made in developing rapid bioassessment schemes (RBS) for SA aquatic ecosystems. Nevertheless, method integration, which also involves heavy-metal pollution monitoring and molecular technology, is necessary to overcome the current challenges of the standardisation of RBS protocols. Citizenry science will also encourage community and stakeholder involvement in sustainable environmental management in SA.
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Wang X, Ma L, Wu J, Xiao Y, Tao J, Liu X. Effective bioleaching of low-grade copper ores: Insights from microbial cross experiments. BIORESOURCE TECHNOLOGY 2020; 308:123273. [PMID: 32247948 DOI: 10.1016/j.biortech.2020.123273] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
The interaction between microorganisms and minerals was a hot topic to reveal the transformation of key elements that affecting bioleaching efficiency. Three typical low-grade copper ores, the main copper-bearing components of which were primary sulfide, secondary sulfide and high-oxidative sulfide copper, were obtained from Dexing, Zijinshan and Luanshya copper mine, respectively. Meanwhile, six typical microorganisms were isolated from each of the three habitats, and assembled as communities based on their origins. Cross bioleaching was carried out under identical conditions. The leaching parameters showed that native strains played excellent roles in their corresponding ore bioleaching process, and community structure was greatly determined by mineral composition, indicating that domestication for longitudinal adaption was an effective way to improve microbial leaching performance. Leptospirillum ferriphilum and Acidithiobacillus ferrooxidans promoted copper release by shifting redox potential and pH of the leachate, respectively, indicating that microbial population regulation was another effective way to improve bioleaching efficiency.
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Affiliation(s)
- Xingjie Wang
- School of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Liyuan Ma
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
| | - Jiangjun Wu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Yunhua Xiao
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China; College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Jiemeng Tao
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Xueduan Liu
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
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