The chemical characteristics of acid mine drainage with particular reference to sources, distribution and remediation: The Witwatersrand Basin, South Africa as a case study

Tutu, Hlanganani; McCarthy, T. S.; Cukrowska, Ewa

doi:10.1016/j.apgeochem.2008.09.002

Cited by 165 publications

(117 citation statements)

References 9 publications

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“…The oxidation process acidifies water in the dams, which then enters the groundwater, affecting water quality by reducing the pH and increasing contamination by heavy metals (Sracek et al 2010). The oxidation process can go down to 5-m depth in sand tailings and down to 2 m on slime dumps (Naicker et al 2003) with marked variations between sites and seasons of the year (Akcil and Koldas 2006;Tutu et al 2008). …”

Section: Environmental and Social Impacts Of Mine Wastesmentioning

confidence: 99%

Progresses in restoration of post-mining landscape in Africa

et al. 2018

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Mining alters the natural landscape and discharges large volumes of wastes that pose serious pollution hazards to the environment, to human health and to agriculture. As a result, the recent 2 decades have witnessed a global surge in research on post-mining landscape restoration, yielding a suite of techniques including physical, chemical, biological (also known as phytoremediation) and combinations. Despite the long history of mining in Africa, no systematic review has summarized advances in restoration research and practices after mining disturbance. Thus, the aim of this review was to document the state-of-knowledge and identify gaps in restoration of postmining landscape in Africa through literature review. We found that: (1) there has been substantial progress in identifying species suitable for phytoremediation; (2) few studies evaluated the feasibility of organic amendments to promote autochthonous colonization of mine wastelands or growth of planted species; and (3) restoration of limestone quarries in Kenya, sand mining tailings in South Africa, and gold mine wasteland in Ghana are successful cases of large-scale post-mining restoration practices in Africa. However, the pace of post-mining landscape restoration research and practice in Africa is sluggish compared to other parts of the global south. We recommend: (1) mainstreaming the restoration of mine wastelands in national research strategies and increased development planning to make the mining sector ''Green''; (2) inventory of the number, area, and current status of abandoned mine lands; (3) expanding the pool of candidate species for phytostabilization; (4) further evaluating the phytostabilization potential of organic amendments, e.g., biochar; (5) assessing the impacts of mining on regional biodiversity.

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Section: Environmental and Social Impacts Of Mine Wastesmentioning

confidence: 99%

Progresses in restoration of post-mining landscape in Africa

et al. 2018

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“…Fe, K, Mn, Zn, and Ni are not enriched, with values EF < 2. The acidification occurring in tailings could justify these results as long as those elements are dissolved in the solution (Espana et al, 2005;Tutu, McCarthy, and Cukrowska, 2008). Tutu, McCarthy, and Cukrowska (2008) reported the occurrence of acidification in tailings in which oxidation reactions contribute to the dissolution of elements such as U, As, Cu, Ni, Co, and Zn.…”

mentioning

confidence: 99%

Health risk posed by enriched heavy metals (As, Cd, and Cr) in airborne particles from Witwatersrand gold tailings

Maseki

Annegarn

Spiers

2017

J. South. Afr. Inst. Min. Metall.

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Severe episodes of windblown dust from mine tailings storage facilities (TSFs) are a common phenomenon on the Witwatersrand, especially during the spring windy season. For communities around TSFs, such events pose health and environmental challenges. This paper reports on health risk assessment using US Environmental Protection Agency (US EPA) risk assessment methods for heavy metal elements in windblown dust from TSFs on the central and east Witwatersrand. Samples of surface material from these TSFs were analysed for heavy metal content using inductively coupled plasma-mass spectrometry (ICP-MS). From a range of 30 heavy metals analysed, only As, Cd, Cr, Pb, and U were enriched by a factor of two or more above the average crustal composition and at concentrations that could be of possible health concern-elements present in the range of a few parts per billion (ppb) or lower were ignored. As, Cd, Cr, Pb and U were selected for a comprehensive risk assessment from exposure through airborne routes, mainly considering inhalation and ingestion. Ambient exposures were based on a worst-case measured episode of 540 μg m -3 (24-hour average), which was projected over each day of an annual exposure for the hours for which the wind speed was above the threshold for dust generation. US EPA risk assessment methods were used to determine the inhalation and ingestion hazard quotients and hazard indices for adults and children. The sum of the hazard indices was assessed to be below the non-cancer benchmark (hazard indices 1.0) considered to be acceptable for a lifetime exposure. The total risk for both exposures (inhalation and the ingestion) was within the range of 1 per 1 000 000 to 100 per 1 000 000-taken as 'acceptable risk' by the US EPA for adults and children. These results represent the first quantitative health risk assessment of the hazard posed by heavy metals in windblown mine tailings dust on the Witwatersrand goldfield. mine tailings, dust, airborne particles, health risk, inhalation, ingestion heavy metals, arsenic, cadmium, chromium.

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“…U removal increased by 27 % between pH 3 and 9, with the greatest increase occurring between pH 5 and 7. At this pH range, a hydrolysis product of uranium, schoepite [(UO 2 ) 8 O 2 (OH) 12 Á12H 2 O] is formed hence the increase in adsorption (Tutu 2006). However, because experiments did not exclude CO 2 , not all uranium precipitated as schoepite due to the formation of uranyl carbonates and hydrogen carbonates (Waite et al 1994;Wazne et al 2006).…”

Section: Effect Of Phmentioning

confidence: 99%

“…The World Health Organization (WHO) drinking water standards stipulate upper limits of 2 mg L -1 , 0.4 mg L -1 and 30 lg L -1 for Cu, Mn and U, respectively (WHO 2011). Yet concentrations as high as 7 mg L -1 for Cu, 129 mg L -1 for Mn and 2.6 mg L -1 for U have been reported for ground and surface waters sometimes used for potable purposes (Naicker et al 2003;Tutu et al 2008;Winde 2010;Saad et al 2013). The removal of these ions from AMD-contaminated waters is therefore necessary to reduce negative effects to humans, aquatic organisms and ecosystems.…”

Section: Introductionmentioning

confidence: 99%

“…In South Africa, mining of base and precious metals has taken place for more than a century and contributed enormously to the growth of the economy. It has also, however, resulted in significant contamination of surface and groundwater by acid mine drainage (AMD) and a suite of metal and radionuclide ions (Naicker et al 2003;Tutu et al 2008;Winde 2010). This contamination is a major concern especially in light of the health risks and negative impacts on ecosystems posed by exposure to excessive metal concentrations (WHO 2011).…”

Section: Introductionmentioning

confidence: 99%

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Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions

2014

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The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by C10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1:2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.

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The chemical characteristics of acid mine drainage with particular reference to sources, distribution and remediation: The Witwatersrand Basin, South Africa as a case study

Cited by 165 publications

References 9 publications

Progresses in restoration of post-mining landscape in Africa

Progresses in restoration of post-mining landscape in Africa

Health risk posed by enriched heavy metals (As, Cd, and Cr) in airborne particles from Witwatersrand gold tailings

Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions

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