The Hazardous Status of High Density Sludge from Acid Mine Drainage Neutralization

Classification of waste is an essential part of waste management to limit potential environmental pollution; however, global systems vary. The objective was to understand the waste classification of high density sludge (HDS) from acid mine drainage (AMD) treatment, according to selected global systems. Three sludges from two limestone treatment plants, and three others from a limestone and lime treatment plant from the Mpumalanga coalfields of the Republic of South Africa (RSA) were evaluated. Systems for the RSA, Australia, Canada, China, and the United States Environmental Protection Agency (USEPA) were considered. The USEPA system rated all six sludges non-hazardous, Canadian and Chinese systems allocated a hazardous status to one sludge from the limestone treatment plants based on Ni solubility. The RSA system considered two of the sludges from limestone treatment plants to be higher risk materials than did the other countries. This was due mainly to the RSA system’s inclusion of Mn and use of appreciably lower minimum soluble levels for As, Cd, Pb, Hg, and Se. None’s use of lime resulted in higher soluble Mn. Minimum leachable concentration thresholds for Cd, Hg, Pb, As, and Se in the RSA system were below method detection limits for Toxicity Characteristic Leaching Procedure (TCLP) extracts, making the guidelines impractical, and revision is advised. Considering all the systems, the probability that the HDS from the coalfields of Mpumalanga, South Africa will be classified as hazardous waste increases if the material is only subjected to limestone treatment because of Ni solubility.

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The influence of a high-density sludge acid mine drainage (AMD) chemical treatment plant on water quality along the Blesbokspruit Wetland, South Africa

Water SA ◽

10.17159/wsa/2021.v47.i1.9443 ◽

2021 ◽

Vol 47 (1 January) ◽

Author(s):

Mauro Lourenco ◽

Chris Curtis

Keyword(s):

South Africa ◽

Water Quality ◽

Surface Water ◽

Acid Mine Drainage ◽

Mine Drainage ◽

Treatment Plant ◽

Surface Water Quality ◽

High Density ◽

Quality Data ◽

Acid Mine

The Eastern Basin chemical acid mine drainage (AMD) treatment plant is one of the world’s largest high-density sludge (HDS) plants, and came into operation in August 2016. The plant is situated near the inoperative Grootvlei Mine in Springs, South Africa, and upstream of the Blesbokspruit Wetland, a former Ramsar Wetland of International Importance, now on the Montreux Record. Since being in operation it has had a major influence on surface water quality along the wetland area. The plant was constructed to mitigate the anticipated decant of AMD water from the abandoned Grootvlei Mine into the Blesbokspruit Wetland. Making use of the BACI (Before-After-Control-Impact) design, this study compares surface water quality of the Blesbokspruit upstream (control site) and downstream (impact site) of the treatment plant for 3-year periods before and after it came into operation. Quarterly water quality data (aluminium, ammonia, chloride, conductivity, dissolved oxygen, fluoride, iron, magnesium, manganese, nitrate, pH, phosphate, sodium and sulphate) from 2013–2019 were used for 5 historical Rand Water monitoring sites along the Blesbokspruit. The current HDS treatment process has negatively influenced conductivity, chloride, magnesium, sodium and sulphate levels downstream. Since the commissioning of the treatment plant, the levels of these parameters have increased significantly. Notably, conductivity and sulphate have reached the management range defined as ‘unacceptable’ within the framework set out by the Blesbokspruit Forum (which is less stringent than the national guidelines for aquatic ecosystems), with potential impacts on salinization of the Vaal Barrage downstream. However, the significant reduction of iron, ammonia and phosphate concentrations downstream of the plant may be a combined beneficial effect of dilution by increased discharge from the plant and the wetland removing these contaminants. These results highlight the need for further research into possible secondary treatment and desalinisation mechanisms and the potential ecological and downstream water supply implications of increasing salinity within the area.

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The Key Factor of Acid Mine Drainage (AMD) in the History of the Contribution of Mining Industry to the Prosperity of the United States and South Africa: A Review

Natural Resources ◽

10.4236/nr.2016.77039 ◽

2016 ◽

Vol 07 (07) ◽

pp. 445-460 ◽

Cited By ~ 3

Author(s):

Shinji Matsumoto ◽

Hideki Shimada ◽

Takashi Sasaoka

Keyword(s):

United States ◽

South Africa ◽

Acid Mine Drainage ◽

Mine Drainage ◽

Mining Industry ◽

The United States ◽

Acid Mine ◽

Key Factor ◽

History Of

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Genome-Wide Association Study of Natural Variation in Arabidopsis Exposed to Acid Mine Drainage Toxicity and Validation of Associated Genes with Reverse Genetics

Plants ◽

10.3390/plants10020191 ◽

2021 ◽

Vol 10 (2) ◽

pp. 191

Author(s):

Bandana Ghimire ◽

Thangasamy Saminathan ◽

Abiodun Bodunrin ◽

Venkata Lakshmi Abburi ◽

Arjun Ojha Kshetry ◽

...

Keyword(s):

Acid Mine Drainage ◽

Association Study ◽

Root Length ◽

Natural Variation ◽

Genome Wide Association Study ◽

Mine Drainage ◽

The United States ◽

Genome Wide Association ◽

Acid Mine ◽

Genome Wide

Acid mine drainage (AMD) is a huge environmental problem in mountain-top mining regions worldwide, including the Appalachian Mountains in the United States. This study applied a genome-wide association study (GWAS) to uncover genomic loci in Arabidopsis associated with tolerance to AMD toxicity. We characterized five major root phenotypes—cumulative root length, average root diameter, root surface area, root volume, and primary root length—in 180 Arabidopsis accessions in response to AMD-supplemented growth medium. GWAS of natural variation in the panel revealed genes associated with tolerance to an acidic environment. Most of these genes were transcription factors, anion/cation transporters, metal transporters, and unknown proteins. Two T-DNA insertion mutants, At1g63005 (miR399b) and At2g05635 (DEAD helicase RAD3), showed enhanced acidity tolerance. Our GWAS and the reverse genetic approach revealed genes involved in conferring tolerance to coal AMD. Our results indicated that proton resistance in hydroponic conditions could be an important index to improve plant growth in acidic soil, at least in acid-sensitive plant species.

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Governance and socio-political issues in management of acid mine drainage in South Africa

Water Policy ◽

10.2166/wp.2017.068 ◽

2017 ◽

Vol 20 (1) ◽

pp. 77-89

Author(s):

Charles Mpofu ◽

Thabiso John Morodi ◽

Johan Petrus Hattingh

Keyword(s):

South Africa ◽

Decision Making ◽

Acid Mine Drainage ◽

Environmental Governance ◽

Mine Drainage ◽

Mineral Resources ◽

Political Issues ◽

Acid Mine ◽

Black Economic Empowerment ◽

Decision Making Processes

Abstract The water resources in South Africa are threatened by current and past mining practices such as abandoned and closed mines. While mining is considered valuable for its contribution to this country's gross domestic product, its polluting effects on water and land resources have been criticised as unsustainable. Acid mine drainage (AMD) is one specific public health and ecological issue that has stirred debates in political and social circles in this country. This paper examines the scalar politics and other related dimensions of water and AMD governance, thereby revealing evidence of deep-rooted challenges regarding the governance of water and mineral resources. The specific focus is on the socio-political context of labour laws and Black Economic Empowerment and the decision-making processes adopted by government. Thus, this paper has implications for the improvement of environmental governance and decision-making strategies and the adoption of a national strategy for adequately addressing AMD and related policy issues.

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