Gold Mine Tailings Research Articles

Improvements in Hydrolytic Stability of Alkali-Activated Mine Tailings via Addition of Sodium Silicate Activator.

Over 14 billion tons of mine tailings are produced throughout the world each year, and this type of waste is generally stored onsite indefinitely. Alkali activation is a promising strategy for the reuse of mine tailings to produce construction materials, converting this waste stream into a value-added product. One major problem with alkali-activated mine tailings is their low durability in water (i.e., low hydrolytic stability). In this article, the influence of a mixed sodium hydroxide/sodium silicate alkali activator on the compressive strength, hydrolytic stability, and microstructure of alkali-activated materials (AAMs) were systematically investigated. XRD, FTIR, NMR, and NAD were used to investigate microstructural changes, and a water immersion test was used to show improvements in hydrolytic stability. For gold mine tailings activated with pure sodium hydroxide, the compressive strength was 15 MPa and a seven-day water immersion test caused a strength loss of 70%. With an addition of 1 M sodium silicate in the activator, the AAMs achieved a compressive strength of over 30 MPa and strength loss of only 45%. This paper proposes a mechanism explaining why the strength and hydrolytic stability of AAMs are dependent on the dosage of soluble silicate. A high dosage of sodium silicate inhibits the depolymerization of the source material, which results in a sample with less amorphous aluminosilicate gel and, therefore, lower hydrolytic stability.

Molecular docking, molecular dynamics simulations and binding free energy studies of interactions between Mycobacterium tuberculosis Pks13, PknG and bioactive constituents of extremophilic bacteria

Mycobacterial pathogens present a significant challenge to disease control efforts globally due to their inherent resistance to multiple antibiotics. The rise of drug-resistant strains of Mycobacterium tuberculosis has prompted an urgent need for innovative therapeutic solutions. One promising way to discover new tuberculosis drugs is by utilizing natural products from the vast biochemical space. Multidisciplinary methods can used to harness the bioactivity of these natural products. This study aimed to evaluate the antimycobacterial efficacy of functional crude extracts from bacteria isolated from gold mine tailings in South Africa. Bacterial strains were identified using 16S rRNA sequencing. The crude extracts obtained from the bacteria were tested against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis mc2155, and Mycobacterium aurum A+. Untargeted HPLC-qTOF and molecular networking were used to identify the functional constituents present in extracts that exhibited inhibitory activity. A virtual screening workflow (VSW) was used to filter compounds that were strong binders to Mycobacterium tuberculosis Pks13 and PknG. The ligands returned from the VSW were subjected to optimization using density functional theory (DFT) at M06-2X/6-311++ (d,p) level of theory and basis set implemented in Gaussian16 Rev.C01. The optimized ligands were re-docked against Mycobacterium tuberculosis Pks13 and PknG. Molecular dynamics simulation and molecular mechanics generalized born surface area were used to evaluate the stability of the protein–ligand complexes formed by the identified hits. The hit that showed promising binding characteristics was virtually modified through multiple synthetic routes using reaction-driven enumeration. Three bacterial isolates showed significant activity against the two strains of Mycobacterium, while only two, Bacillus subtilis and Bacillus licheniformis, exhibited activity against both Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis mc2155, and Mycobacterium aurum A+. The tentatively identified compounds from the bacterial crude extracts belonged to various classes of natural compounds associated with antimicrobial activity. Two compounds, cyclo-(L-Pro-4-OH-L-Leu) and vazabitide A, showed strong binding against PknG and Pks13, with pre-MD MM-GBSA values of − 42.8 kcal/mol and − 47.6 kcal/mol, respectively. The DFT-optimized compounds exhibited the same docking scores as the ligands optimized using the OPSL-4 force field. After modifying vazabitide A, its affinity to the Pks13 binding site increased to − 85.8 kcal/mol, as revealed by the post-MD MM-GBSA analysis. This study highlights the potential of bacteria isolates from gold mine tailings as a source of new scaffolds for designing and optimizing anti-Mycobacterium agents. These agents synthesized in-silico can be further tested in-vitro to evaluate their efficacy.

Radon exposure risks among residents proximal to gold mine tailings in Gauteng Province, South Africa: a cross-sectional preliminary study protocol.

Gold mine tailings, a legacy of the mining industry, harbors significant amount of radon gas, a classified human carcinogen. Radon exposure, especially near tailings, is a significant public health threat, potentially leading to increased risk of lung cancer, leukemia, and chronic obstructive pulmonary disease (COPD). These health problems are often associated with lower survival rates and significant financial burdens. This ongoing research aim to evaluating the relationship between indoor radon exposure and lung cancer, leukemia, and COPD risks among residents proximal to gold mine tailings in Gauteng Province, South Africa. This cross-sectional preliminary study focus on two distinct groups: Riverlea (exposed group, <2 km to Gold mine tailings) and Orlando East (unexposed group, >2 km to Gold mine tailings). Indoor radon levels is measured using AlphaE monitors, while health risks (lung cancer, leukemia, and COPD) linked to exposure are evaluated through interview-administered questionnaire and secondary data from Gauteng Health Department. Of the 476 residents randomly selected for this study, 300 have already participated, with balanced representation from both the exposed and unexposed groups. The study will compare indoor radon levels and health outcomes between the two groups. This study's results could aid in creating targeted interventions and policies to mitigate indoor radon exposure risks and safeguard vulnerable communities from this significant public health hazard.

Towards net-zero emission: A case study investigating sustainability potential of geopolymer concrete with recycled glass powder and gold mine tailings

This study explores the feasibility of utilizing waste materials, specifically glass powder (GP) and gold mine tailings (MT), as eco-friendly, net-zero emission alternatives in geopolymer concrete production. The optimal material proportions that yield maximum compressive strength are identified using response surface methodology. The optimized concrete mixtures are comprehensively evaluated for three core attributes; namely, fresh-state properties, such as workability and air content; mechanical characteristics, including compressive, flexural, and splitting tensile strengths; and long-term durability, assessed by freeze-thaw resistance and chloride permeability. In the evaluation of fresh-state properties, it was observed that GP improved workability, whereas MT had a decreasing effect due to its increased fineness and greater surface area. The study also revealed that the combined addition of GP and MT notably increased compressive strength by up to 25%, despite the addition of GP alone slightly reducing the mechanical properties. While these waste materials positively influenced flexural and splitting tensile strengths, the impact was less significant compared to that on compressive strength. Furthermore, in critical durability tests that involve 300 freeze-thaw cycles and rapid chloride permeability assessments, mixtures that contain GP and MT exceeded standard benchmarks. The results indicate that the incorporation of GP and MT together not only enhances mechanical properties but also improves durability. These results demonstrate the potential application of GP and MT as sustainable substitutes in concrete production.

Cyanidation of tailings in artisanal small-scale gold mining at Arbaat Region in Red Sea State, Sudan

In this research, the processing of gold from artisanal small-scale gold mining was investigated by cyanidation using an agitation process. The sample's characterization shows that the silicate mineral exhibits the sample mineralogy, according to the results of the XRD examination. In XRF analysis, the mineralogical and chemical structure shows 77.1% SiO2, 8.08% Al2O3, 5.76% Fe2O3, 1.67% CaO, 0.97% K2O, 0.054% As2O3, 1.1% Na2O, 0.392% SO3, 0.454% TiO2, 0.049% MnO and 0.005% ZrO. The parameters of the experiments were stirring speed, NaCN concentration, solid-liquid ratio, temperature, and pH. The purpose of gold leaching in artisanal small-scale gold mining at Arbaat region is to find the appropriate conditions that will ensure maximum recovery. It was found that the gold dissolution decreases with increasing solid ratio. Furthermore, the cyanide concentration positively influences the range of 0.05–0.5 g/L. It is seen that the dissolution rate increases with the range of pH 10-10.30, while it starts to incline at pH after 10.30. However, the temperature and agitation speed have a significant effect on the gold dissolution. Cyanidation tests revealed that it is easy to apply the cyanidation process and recover about 87.52% Au content from the tailings of artisanal small-scale gold mining. The obtained recovery indicates the commercial and economic viability of the process that will be applied to extract Au from artisanal small-scale gold mining tailings in Arbaat.

Positive interaction of trembesi (Samanea saman) and arbuscular mycorrhizae fungi in Pb stabilization of gold-mine tailing media

Abstract. Setyaningsih L, Ramadhani FA, Muttaqin Z, Maslahat M. 2024. Positive interaction of trembesi (Samanea saman) and arbuscular mycorrhizae fungi in Pb stabilization of gold-mine tailing media. Biodiversitas 25: 379-385. This experiment aimed to determine the ability of trembesi (Samanea saman Merr.) seedlings inoculated with AMF (Glomus manihotis) to reduce Pb from gold mine tailings media. Therefore, using plants and Arbuscular Mycorrhizae Fungi (AMF) is an alternative choice that can be considered to support a phytoremediation program to reduce Pb contamination in tailing areas. The experiment was conducted using a completely randomized design in a greenhouse with two factors, i.e., with and without AMF, and four different Pb treatments (0, 0.5, 1, and 1.5 mM). AMF-inoculated seedlings were grown on tailings media and exposed to Pb in different concentrations for 5 weeks. The results showed that the seedlings were still able to grow on the media with Pb up to 1.5 mM with a tolerance index of 91.6%. AMF induced the plant to accumulate Pb dramatically higher, even though this absorption tended to reduce plant biomass. Root tissue stored significantly higher Pb than stem and leaf tissue, with an average concentration was 526.29 mg/kg in the roots of mycorrhizal seedlings. The bioaccumulation level of Pb in mycorrhizal seedlings was significantly higher. The value of the transport factor was below 1, indicating that S. saman seedlings carried out the phytostabilization. The interaction of AMF with S. saman has a big potential to be applied in efforts to remediate Pb in tailings.

Determination of Bioavailability, Potential Ecological and Human Health Risks, and Biomonitoring of Potential Toxic Elements in Gold Mine Tailings from Four Areas of Antioquia, Colombia

Gold mining has helped many countries and regions grow and prosper. Yet, because of the significant environmental effects produced, waste management (mine tailings) has emerged as a crucial issue for the sector. In this study, the concentrations of several potential toxic elements (PTEs) (Fe, Zn, Cu, As, Hg, Pb, Cr, Cd, and Ni) in mine tailings from four gold mining operations (Yalí, Puerto Berrio, Buriticá 1, and Buriticá 2,) were quantified. A biomonitoring system has also been suggested, along with two environmental risk indexes for ecosystems and human health. To do this, composite samples of tailings were collected from the four regions. A PTEs analysis using an ICP-OES as well as physicochemical characterization (pH, electrical conductivity, cation exchange capacity, organic matter) have been performed. Indicators such as antioxidant activity and H2O2 content in Phaseolus vulgaris plants have been used to estimate the bioavailability of PTEs. In contrast to the pseudo-total concentration, the data showed that the bioavailable concentration of PTEs correlated with the risk. The ecological system and public health are more at risk from the mine tailings in Buriticá and Puerto Berrio. It has been demonstrated that P. vulgaris is a quick and effective technique to assess the danger to the environment and public health connected with mining regions, according to the suggested biomonitoring system. The findings of this study can assist the relevant authorities in taking quick action to improve environmental protection and risk management of hazardous waste in gold mining areas.

Characteristics of rhizobacteria in potential hyperaccumulator vegetation and their resistance to gold mine tailing stress

The use of local bacteria is preferred in bioleaching as an environmental-friendly alternative technology in gold mining. In a preliminary study, rhizobacteria were isolated and cultured from three types of hyperaccumulator vegetation from the Ratatotok gold mine, Indonesia, namely Pteris vittata L., Syzygium aromaticum L., and Swietenia mahagoni Jacq. These rhizobacteria still need to be characterised and identified. This study is aimed to cover bacterial phenotypic characterisation, assessment of bacteria resistance to tailing, and identification of bacterial strains the exhibit the highest resistance to tailings. The assessment was carried out across a spectrum of tailing concentrations, selecting the three most robust strains for molecular identification. The process involved genotypic characterisation to determine the species name by analysing the 16S rRNA gene. The results reveal that the phenotypic characteristics of the bacteria isolates vary, but all of them are the indole acetic acid (IAA) hormone producers. The highest IAA producer is the isolate from the rhizosphere of S. aromaticum. Based on the genotypic characterisation test, three most resistant isolates to tailing stress are the following strains Pseudomonas aeruginosa (RTKP1) and Stenotrophomonas geniculata (RTKP2), both from the rhizosphere of P. vittata; as well as Bacillus cereus (RTKS) from the rhizosphere of S. aromaticum. These three strains need to be further tested for their bioleaching capability to recover gold from tailings. Additionally, this study recommends that gold recovery using biological agents can combine the role of hyperaccumulator plants in phytomining and rhizobacteria in bioleaching.

Screening and profiling of mercury-resistant Azotobacter isolated from gold mine tailing in Pongkor, West Java

Mercury (Hg) is a hazardous pollutant produced during the amalgamation of gold extraction. The environmental problems related to improper Hg waste management have become progressively concerning. Hg contamination in environments can be removed by using bioremediation technology. Utilizing Hg-resistant (HgR) microorganisms in Hg bioremediation is a crucial strategy. Azotobacter is one of the potential microbes for Hg bioremediation bioagent due to exopolysaccharides synthesis that binds the heavy metal. The study's main objective was to select and profile a novel Hg-resistant Azotobacter isolated from heavily Hg-contaminated soil and tailing of artisanal and small-scale gold in Pongkor area, West Java, Indonesia. The completely randomized design was used for profiling Azotobacter-HgR and included Hg values of 0, 1, 10, 100, 200, and 400 mg/L. Further, Azotobacter isolate bioassay steps included soil contaminated with Hg, soil contaminated with Hg + Azotobacter sp. S6.a, soil contaminated with Hg + consortium. The profiling results revealed that four Hg-resistant isolates were Azotobacter sp. S5, Azotobacter sp. S6, Azotobacter sp. S6.a, and Azotobacter sp. S9. More importantly, Azotobacter sp. S5 followed by Azotobacter sp. S6.a was found to be the most resistant to Hg exposure at a concentration of 400 mg/L. The Azotobacter sp. S9. produced the lowest EPS, but had the highest activity of nitrogenase and organic acid production. Meanwhile, Azotobacter sp. S6.a. produced the highest EPS. Isolate S5 showed the highest potential as a resistant PGPR-Hg isolate for enhancing the growth of sorghum in Hg-contaminated soil. Sorghum plants accumulate Hg from the soil in the roots but not in the shoots. Present findings suggest that these two isolates have the potential to be used as biological agents to rehabilitate Hg-contaminated soil in Pongkor area.

Exploring the accumulation capacity of dominant plants based on soil heavy metals forms and assessing heavy metals contamination characteristics near gold tailings ponds

Heavy metal contamination of soil commonly accompanies problems around gold mine tailings ponds. Fully investigating the distribution characteristics of heavy metals and the survival strategies of dominant plants in contaminated soils is crucial for effective pollution management and remediation. This study aims to investigate the contamination characteristics, sources of heavy metals (As, Cd, Pb, Hg, Cu, Zn, Cr, and Ni) in soils around gold mine tailings ponds areas (JHH and WZ) and to clarify the form distribution of heavy metals (As, Cd, Pb, Hg) in contaminated plots as well as their accumulation and translocation in native dominant plants. The results of the study showed that the concentrations of As, Pb, Cd, Cu, and Zn in soil exceeded the national limits at parts of the sampling sites in both study areas. The Nemerow pollution index showed that both study areas reached extreme high pollution levels. Spatial analysis showed that the main areas of contamination were concentrated around metallurgical plants and tailings ponds, with Cd exhibiting the most extensive area of contamination. In the JHH, As (74%), Cd (66%), Pb (77%), Zn (47%) were mainly from tailings releases, and Cu (52%) and Hg (51%) were mainly from gold ore smelting. In the WZ, As (42%), Cd (41%), Pb (73%), Cu (47%), and Zn (41%) were mainly from tailings releases. As, Cd, Pb, and Hg were mostly present in the residue state, and the proportion of water-soluble, ion-exchangeable, and carbonate-bound forms of Cd (19.93%) was significantly higher than that of other heavy metals. Artemisia L. and Amaranthus L. are the primary dominating plants, which exhibited superior accumulation of Cd compared to As, Pb, and Hg, and Artemisia L. demonstrated a robust translocation capacity for As, Pb, and Hg. Compared to the concentrations of other forms of soil heavy metals, the heavy metal content in Artemisia L correlates significantly better with the total soil heavy metal concentration. These results offer additional systematic data support and a deeper theoretical foundation to bolster pollution-control and ecological remediation efforts in mining areas.

Characteristics of Soil Arsenic Contamination and the Potential of Pioneer Plants for Arsenic Remediation in Gold Mine Tailings.

Arsenic (As) contamination of gold mine tailings poses major threats to the natural environment and human health, necessitating adequate management measures. To investigate the soil As contamination level and the potential of pioneer plants for As remediation, the soil and plants of an abandoned gold mine tailings in the Qinling Mountains were analyzed. The level of As contamination was assessed using the single-factor pollution index and potential ecological risk index, and its bioeffectiveness was analyzed. The enrichment capability of plants was investigated using the bioaccumulation factor and translocation factor. Redundancy analysis and partial least squares regression were employed to investigate factors affecting the distribution of As in soil and plants. The results show that As in soil mainly existed in the difficult-available state, with serious contamination and extremely high ecological risk. Lythrum salicaria L. and Equisetum ramosissimum Desf. are the preferred plants for remediation of As contamination through screening pioneer plants. Soil total nitrogen (STN) and available phosphorus (SAP) are the main factors influencing the characteristics of As distribution in the soil. Soil available potassium (SAK), water content (SWC), and SAP promote the accumulation of As by plants. This study provides plant materials and new ideas for mine ecological remediation.

Mechanical Evaluation of Geopolymer Mortars Derived from Gold Mining Tailings under Differents Atmospheres

In this work, geopolymeric mortars made from formal and informal gold mining tailings (Peru) were studied in order to analyze their durability and mechanical resistance in compression. The manufactured mortars were subjected to uniaxial compression tests in four atmosphere conditions: dry air (0% humidity), saline air (5% with sodium cholride), humid air (99% relative humidity) and normal air (with relative humidity at 25%). During the compression tests, the thermoresistance at room temperature (between 11), 200 °C and 500 °C were also evaluated. The results obtained were contrasted with the mechanical resistance of mortars made with conventional cement (Control). The real density and porosity of the different mortars studied were also evaluated, finding real density and porosity values of 2.42 g/cm3 and 19%, 2.62 g/cm3 and 32%; and 2.71 g/cm3 and 36% for conventional cement mortars (Control), tailings geopolymeric mortars from informal mining (GI) and tailings geopolymeric mortars from formal mining (GF), respectively. The mechanical results obtained show average values of maximum compressive strength of 86 MPa, 23 MPa and 19 MPa for Control mortars, GI mortars and GF mortars, respectively. It was also possible to appreciate that the geopolymeric mortars presented cracks, superficial efflorescence, affecting the mechanical resistance in humid and saline atmosphere conditions. The simulated climatic conditions, in which it could have a better mechanical behavior, is a normal atmosphere and dry air. Regarding the evaluation of thermoresistance, they were at a temperature of 500°C, which presented greater mechanical resistance.

Assessing environmental radon contribution by different sources near a South African gold mine tailings

Assessing environmental radon contribution by different sources near a South African gold mine tailings

Dark septate endophyte inoculation improved Pb phytoremediation of Jatropha curcas and Reutealis trisperma on gold mine tailings

This study investigated the symbiotic potential of Jatropha curcas and Reutealis trisperma with two isolates of dark septate endophyte (DSE) fungi (Cladosporium sp. and Rhyzopycnis vagum) grown on gold mine tailings media based on their ability to remediate Pb and their morphological, physiological, and anatomical changes. The targeted plants were grown for 12 weeks on different media contained mixed soil and compost, gold mine tailings, and tailing with additional charcoal. The result showed that DSE inoculation increased the height of J. curcas up to 24.1% in contaminated soil compared to control treatment without DSE. All DSE fungi were able to colonize both root plant even under gold mine tailing treatment. DSE inoculation increased chlorophyll content of both plants ranging from 11% to 33% compared to the plants without DSE. Jatropha curcas inoculated with DSE had the potential to be used as phytoremediation plant with a phytoextraction mechanism indicated by higher translocation factor (TF) value. Meanwhile, the R. trisperma was able to be used for phytoremediation categorized as phytostabilization due to lower TF values. The results of this study highlighted the possible role of the DSE symbiotic with J. curcas and R. trisperma to improve the efficiency of phytoremediation in contaminated lands.

Evaluation of Indoor Radon Activity Concentrations and Controls in Dwellings Surrounding the Gold Mine Tailings in Gauteng Province of South Africa.

Radon in dwellings is recognized as the primary source of natural radiation exposure to members of the public. In the West Rand District and Soweto in the Gauteng Province (South Africa), indoor radon (222Rn) mapping was carried out to assess the exposure levels of radon in dwellings around gold and uranium mining tailings dams. This study was conducted predominately during warm and cold seasons, using the solid-state nuclear track detectors. In summer months, the indoor radon levels measured in all areas ranged from below the lower limit of detection to 71 Bq/m3, with a mean value of 29 Bq/m3, whereas in winter, the levels ranged between 11 and 124 Bq/m3, with a mean value of 46 Bq/m3. Higher indoor radon levels are found in colder months (winter season) than warmer months (summer season). However, no dwellings with indoor radon levels that exceed the WHO (2009) recommended reference level of 100 Bq/m3 were found, except for one that was constructed directly on soil mixed with tailings material. It is recommended that residents should keep their indoor radon levels low through continuous ventilation so as to minimize the buildup of radon and the likelihood of increased health hazards associated with radon exposure.

The effect of compost on the growth of forest plants in the gold mine tailings of PT. Kasongan Bumi Kencana, Central Kalimantan, Indonesia

Mining activities is consequence of development which will result in ex-mining land, causes of environmental changes include chemical, physical and biological. Physically, the land is damaged, the top soil layer become sand, gravel and granite. Chemically, land not longer provide nutrients for plant growth. Biologically, the less of microorganisms especially decomposers. Revegetation is an effort to improve mine land to increase biodiversity, restore landscape aesthetics, control erosion and runoff. The aims of this study to determine the potential growth of Shorea balangeran, Combertocarpus rotundatus, Melaleuca cajuputi and Alstonia scholaris by applying compost to a gold mine’s Tailing Storage Facility (TSF); 7 year (Mirah 1) and 1 year (Mirah 2). The results of the study on TSF Mirah 1, the percentage of growth M. cajuputi and A. Scholaris was 100%, the highest average height and diameter was M. Cajuputi (MeanH+SD-H) 166.70 + 32.16 cm and (MeanD+SD-D) 1.35 + 0.62 cm. The TSF Mirah 2, the percentage of growth S. balangeran and A. Scholaris was 100%, the highest average height was M. cajuputi (MeanH+SD) 137.30 + 23.43 cm and the highest average diameter was A. scholaris (MeanD+SD-D) 1.23 + 0.38 cm.

Potential Toxic-Element Pollution in Surface Water and Its Implications for Aquatic and Human Health: Source–Pathway–Receptor Model

This study focused on assessing the extent of pollution in both flowing and non-flowing surface water within the Matjhabeng mining area of South Africa, with particular emphasis on the substantial impact of gold mine tailings. A comprehensive analysis of physical water-quality attributes, including potentially toxic elements (PTEs), and relevant pollution risk indices was undertaken. To comprehensively elucidate the potential risks to aquatic organisms and human health, a risk assessment framework predicated upon the source–pathway–receptor model was developed. Principal Component Analysis (PCA) was employed as a multivariate statistical tool to discern the potential origins of PTE contamination within the environment. The results substantiate pronounced pollution manifestations within the surface water milieu of the Matjhabeng mining area. Specifically, concentrations of critical PTEs, such as arsenic, cobalt, copper, iron, selenium, and zinc, exhibited transgressions of the regulatory thresholds stipulated by both the South African Department of Water Affairs and Forestry (DWAF) and the Canadian Council of the Ministers of the Environment (CCME). Additionally, concentrations of the aforementioned elements exceeded the stipulated DWAF guidelines for irrigation water usage. Pollution indices, encompassing the Single-Factor Pollution Index and the Nemerow Integrated Pollution Index, discerned moderate contamination stemming from As, while remarkably elevated pollution levels were identified for selenium. PCA elucidated 94.5% of the aggregate variance, revealing cobalt, copper, nickel, and zinc as coalescing within PC1, indicative of a common anthropogenic provenance that is conceivably linked to historical gold mine tailings. PC2 exhibited an aggregation of chromium, iron, and lead, reaffirming this shared anthropogenic etiology. The third PCA component was characterized by selenium, followed by arsenic and magnesium in the fourth. The resultant PTE contamination underscores a profound ecological and public health risk, impacting both the aquatic ecosystems and the local community within the precincts of the Matjhabeng Local Municipality (MLM) area, with consequential amplification of susceptibilities to deleterious health consequences. Urgent and concerted interventions are imperative to ameliorate the emergent decline in surface-water quality within the MLM locale. The adoption of nature-based remediation paradigms holds promise for efficaciously elevating water quality, ameliorating community health, and underpinning the long-term economic viability of the region.

Biocrusts significantly affect the bioavailability and ecological risk of heavy metals in gold mine tailings

Biocrusts significantly affect the bioavailability and ecological risk of heavy metals in gold mine tailings

Gold and Iron Tailings to Improve the Compressive Strength and Workability of Concrete

This scientific study aims to determine the optimal replacement percentage of mine tailings as a substitute for fine aggregate to improve both the compressive strength and the workability of the concrete, both in the case of gold mine tailings and gold mine tailings iron. It is a documentary, bibliographical and descriptive investigation that follows a deductive method with a quantitative approach. In addition, it is descriptive, correlational, and explanatory, with a descriptive level and a non-experimental, longitudinal, and retrospective design. The results indicate that the incorporation of 15% gold mining tailings increases the compressive strength by 4,44% while incorporating 12% iron mining tailings increases the resistance to compression by 7,79%. Likewise, by adding 30% gold mining tailings, a notable increase of 74,36% in tensile strength is obtained. On the other hand, when 5% gold mine tailings are added, the slump remains at 4"; however, by increasing the addition to 10%, it decreases from 2" to 1.77". In the case of tailings iron miners incorporating 30% the settlement remains at 2"; but by increasing the amount to 12%, the slump decreases from 3.32" to 1.57". Finally, the study shows that using mine tailings as a substitute for fine aggregate can significantly improve the compressive strength and workability of concrete, depending on the type of tailings and its percentage of incorporation.

The effect of organic matter on soil organic carbon and water spinach grown in gold mine tailings

The disposal of tailings generated from mining activities poses environmental challenges due to their low fertility and limited suitability for plant growth. This study aimed to investigate the potential of cow manure application in improving the organic-C content of tailings and enhancing the growth of water spinach (Ipomoea reptans). This experiment was laid out in a randomized block design with five treatments and five replications. The treatments involved the application of cow manure at different doses and control, which consisted of; (A) Control, (B) 150 g, (C) 300 g, (D) 450 g, (E) 600 g. The results revealed a significant increase in the organic-C content of tailings following the application of cow manure. The highest organic-C content of 7.47% was achieved with the application of 600 g of cow manure. The application of 150 g of cow manure resulted in the tallest plants with higher fresh and dry weights. The findings from this study underscore the importance of organic amendments in enhancing the organic-C content and promoting plant growth in low fertility growth medium. Further research on the long-term effects and optimization of cow manure application in tailing-based growth substrates is recommended to enhance soil fertility and maximize plant productivity.