Abandoned Mine Ponds Research Articles

Characterization of mine spoils for the reclamation of degraded lands of the Jos-Bukuru tin field, central Nigeria

Tin mining operations on the Jos Plateau have left a lasting impact on the environment, resulting in derelict land, mine spoils, and over a thousand abandoned mining ponds. These ponds have become potential hazards, endangering unsuspecting members of the public. This study aims to provide a comprehensive geochemical and geotechnical characterization of the mine spoils to assess their suitability for the reclamation and restoration of the degraded mined lands. The geochemical analysis reveals that the mine spoils exhibit a strong to moderate level of acidity, with a pH range of 3.91 to 5.90 (average: 4.85). Furthermore, they display deficiencies in essential nutrients such as phosphorus (average: 0.02%) and potassium (average: 0.31%), as well as trace elements such as copper (average: 19.15 ppm), manganese (average: 165.15 ppm), and zinc (average: 53.24 ppm). Notably, the mine spoils are enriched in iron (average: 6.31%). These findings highlight the inadequate presence of both micronutrient and macronutrient elements necessary for successful revegetation which is a crucial component of reclamation. Results from the geotechnical tests indicate that the mine spoils possess an average fines content of 56.03%, a mean liquid limit of 38.06%, and a mean plasticity index of 15.52%. Additionally, the average linear shrinkage value is measured at 10%. The average values for maximum dry density (MDD) and optimum moisture content (OMC) are 1.65 g/cm³ and 19%, respectively. The unsoaked California bearing ratio (CBR) averages 34.64%, while the coefficient of permeability for the spoil is approximately 1.24x10-3 mm/sec. Furthermore, the spoils average cohesion (C) was measured to be 12.150 while the mean angle of internal friction is 30.77 KN/M2. These results collectively indicate that mechanical and chemical stabilization, involving the use of lime, fly ash, and other soil-stabilizing agents is imperative for the effective reclamation of the degraded lands using the mine spoils. Such measures if adopted and implemented will mitigate the risk of accidents and drowning incidents from mining ponds and other abandoned pits involving unsuspecting members of the public and will contribute to the overall environmental restoration efforts in the Jos-Bukuru Tin Field.

Machine Learning Application to Optimize Spent Mushroom Compost (SMC) Biochar as Filter Media for Heavy Metal Adsorption in Abandoned Mine Water

AbstractThe surging global population strains resources, escalating pollution, and exacerbating water scarcity. Sustainable water management necessitates alternative sources such as abandoned mine water. However, these sources often contain hazardous heavy metals, like lead, copper, iron, and manganese, posing grave health and environmental risks. Conventional methods struggle to effectively treat these heavy metals in abandoned mining ponds, urging the search for cost‐efficient and sustainable solutions. Biochar, particularly from spent mushroom compost (SMC), emerges as a potent adsorbent due to its high surface area and binding groups. Yet, the variability in its efficiency remains a challenge. Conventional empirical models fail to capture the dynamic nature of adsorption processes accurately. Adopting machine learning, specifically an adaptive neuro‐fuzzy inference system (ANFIS), shows potential in predicting adsorption efficiency. This study aims to employ ANFIS to forecast SMC biochar's performance in a lab‐scale metal retention pond, providing design charts for diverse initial metal concentrations and pH levels. Validation through real cases aims to enhance accuracy and establish a framework for future heavy metal adsorption capacities. This research offers a sustainable approach to removing heavy metals from abandoned mining ponds whereas the computational modeling in optimizing SMC biochar introduces a novel approach for practical applications.

Assessing fish diversity in abandoned mining ponds in Madre de Dios, Peru, using environmental DNA

AbstractThe Peruvian region of Madre de Dios is a biodiversity hotspot located in the Andean‐Amazon region. Since the 1970s, it has experienced the harsh effects of artisanal and small‐scale gold mining (ASGM), which has transformed the primary forests into numerous small mining ponds left abandoned after extraction. Preliminary surveys indicate that these ponds are being recolonized by surrounding biodiversity. These assessments are typically carried out using traditional methods that are costly, difficult to deploy at multiple locations, and have raised safety concerns. In this context, environmental DNA (eDNA) becomes a useful tool for biodiversity monitoring due to its simplicity for sample collection and performance to identify taxonomic groups. In this study, we evaluated fish biodiversity in two mining ponds created by ASGM along with two nearby pristine lakes, unimpacted by mining operations but also influenced by seasonal flooding. We compared two alternative eDNA processing methods and contrasted our results with historic data from traditional biodiversity monitoring. Both eDNA‐based methods yielded comparable results, varying only in logistic requirements and costs. In total, we detected 85 fish MOTUs (22 at the species level) from 5 orders, 22 families, and 41 genera. Some of the species identified with eDNA were rarely registered by traditional monitoring, and we could identify 6 genera associated with ASGM mining ponds only. A major restriction of the eDNA approach in this location was the insufficient local taxa registered in genomic databases which limited our taxonomic resolution. Despite this limitation, our results indicate that eDNA could be a powerful tool for biodiversity estimations in the Western Amazon, identifying more taxa, with much less time and money invested than traditional monitoring. Our results also confirm that abandoned mining ponds are being recolonized by surrounding ichthyofauna, reaching richness levels above nearby unmined oxbow lakes used as reference.

Mercury bioaccumulation in bats in Madre de Dios, Peru: implications for Hg bioindicators for tropical ecosystems impacted by artisanal and small-scale gold mining.

Mercury (Hg) endangers human and wildlife health globally, primarily due to its release from artisanal small-scale gold mining (ASGM). During gold extraction, Hg is emitted into the environment and converted to highly toxic methylmercury by microorganisms. In Madre de Dios (MDD), Peru, ASGM dominates the economy and has transformed rainforests into expansive deforested areas punctuated by abandoned mining ponds. The aim of this study was to evaluate the use of bats as bioindicators for mercury pollution intensity in tropical terrestrial ecosystems impacted by ASGM. We collected 290 bat fur samples from three post-ASGM sites and one control site in Madre de Dios. Our results showed a wide Hg distribution in bats (0.001 to 117.71 mg/kg) strongly influenced by feeding habits. Insectivorous and piscivorous bats from ASGM sites presented elevated levels of Hg surpassing the mercury small mammal threshold for small mammals (10 mg/kg). We observed the highest reported fur mercury concentrations for insectivorous Neotropical bats reported to date (Rhynchonycteris naso, 117 mg/kg). Our findings further confirm that Hg emissions from ASGM are entering local food webs and exposing wildlife species at several trophic levels to higher levels of Hg than in areas not impacted by mining. We also found that three bat genera consistently showed increased Hg levels in ASGM sites relative to controls indicating potential usefulness as bioindicators of mercury loading in terrestrial ecosystems impacted by artisanal and small-scale gold mining.

Health risk assessment of potentially toxic elements (PTEs) concentrations in soil and fruits of selected perennial economic trees growing naturally in the vicinity of the abandoned mining ponds in Kuba, Bokkos Local Government Area (LGA) Plateau State, Nigeria.

This study was designed to determine the level of potentially toxic elements (PTEs) contamination in soil and selected fruits and assesses the health risk of inhabitants in the abandoned tin mining community in Kuba, Bokkos LGA. Samples of the abandoned mine soil and selected fruits mango (Magnifera indica), guava (Psidium guajava), avocado pear (Persea americana), and banana (Musa spp)) from the vicinity of the abandoned mine were analyzed for the presence of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the levels of all the PTEs analysed in the abandoned mine soil samples were significantly (p < 0.05) higher than their corresponding values in the control soil from the non-mining area. Except for Cd, the mean concentrations of As, Cr, Cu, Mn, Ni, and Pb were significantly higher than the FAO/WHO maximum permissible limit. Except for Zn in guava fruits and Cd in avocado fruits, the mean concentration of PTEs in fruits from abandoned mines was significantly (p < 0.05) higher than their corresponding control values. In contrast, the mean levels of As, Cr, Cu, Mn, Ni, and Pb in the investigated fruits were significantly (p < 0.05) higher than FAO/WHO maximum permissible limits established for fruits. The studied fruits remarkably took up and bioaccumulated PTEs from the abandoned mine soil. Mango fruit significantly bioaccumulated As (5.40), Cd (3.40), and Zn (2.81). Guava fruit bioaccumulated As (1.50) and Cd (4.60), while avocado bioaccumulated As (3.53), Cd (3.80), and Zn (6.48). Banana bioaccumulated As (0.96), Cd (0.80), and Zn (6.78). The hazard quotient values for PTEs investigated in fruits for adults, and children were several folds greater than 1. The hazard index (HI) for the PTEs through consuming fruits for children and adults was greater than 1, indicating that possible health risks exist for both local children and adults. However, the HI values for the children were higher than those for adults, implying that children were exposed to more potential noncarcinogenic health risks from PTEs than adults. The total cancer risk (TCR) values for Cr and Ni for all the fruits studied were within 10-3-10-1, which is several-fold higher than the permissible limits (10-6and < 10-4), indicating high carcinogenic risk. TCR values for Cd and Pb in all the fruits, except for Cd in guava and avocado fruits for children, were within the range of 10-5-10-4, indicating that they are associated with moderate risk. The CR values for all the PTEs in all the fruits for adults and children except for mango fruit adults were within 10-2-10-1, indicating high carcinogenic risk. In conclusion, the results and risk assessment provided by this study indicate that human exposure to fruits from abandoned mines suggests a high vulnerability of the local community to PTE toxicity. Long-term preventive measures to safeguard the health of the residents need to be put in place.

Bioaccumulation and Risk Analysis of Selected Heavy Metals in Clarias Gariapinus and Tilapia Zili Fish Species of Abandoned Mining Ponds

Heavy metals (Cd, Co, Cr, Cu, Ni and Pb) were determined in some selected fish species (Clarias gariepenus and Tilapia zili) from Bokkos abandoned mining sites. Sample matrices examined were flesh gills, kidney and liver of each fish species. Twenty (20) sample sites were selected for the sample matrices under investigation. After sample collection and treatment, heavy metals were determined using Atomic Absorption Spectrophotometer (AAS, Bulk Scientific Model 210 VGP). The concentration patterns for each of the elements in the fish species showed significant and relatively similar patterns in cat fish with Ni having the highest concentration, followed by Cr, Co, Pb Cd and Cu in that order with respective. Cumulative bioconcentration in Tilapia zili showed that Cd &lt; Cu &lt; Pb &lt; Co &lt; Cr &lt; Ni respectively. Pearson correlation showed various interactions and relationships existing between and within sample matrices, indicating that these heavy metals have similar source, species or geochemical interaction. Only Co has a weakly positive correlation 0.58 with Pb while in Tilapia zilli, while Cu has correlation with Ni in Clarias gariepenus. Also the interactions and behaviors of the fish species suggests water and sediment for Cu, Ni and Co, Pb respectively. The relative contributions of Cr, Ni and Pb to the aggregated risk were 59.86%, 0.21%, 38.03% and 1.76% respectively. Consumption of these fish species from the study area therefore poses serious health concern upon consumption over time.

Assessment of dissolved mercury by diffusive gradients in thin films devices in abandoned ponds impacted by small scale gold mining

In order to fulfil the Minamata Convention on Mercury, it is necessary to monitor the Hg contamination in freshwater ecosystems nearby artisanal and small scale gold mining (ASGM) areas. Since most of these ASGM communities are located in remote areas, a convenient method for sampling, preserving and transporting samples is needed. In this study we evaluated the feasibility of the diffusive gradient in thin-films (DGT) technique to detect and quantify the labile fraction of Hg and other metals (Pb, Cu, Zn, Cd, Ni, Mn and Cr) in a hard-to-reach gold mining district in the state of Chocó, Colombia. We deployed DGT at sampling sites along the Atrato river and abandoned mining ponds (AMPs) which were deserted in different periods since 1997 to 2019 (6–15 years). In average, the labile THg concentrations in AMPs (148.9 ± 43.2 ng L−1) were a 50% higher than in the river water (99.9 ± 37.4 ng L−1). In the ponds, no significant differences were found in labile Hg with respect abandonment period. Labile Ni (0.9–493.1), Mn (1.33–11.48), Cu (0.030–2.233), and Zn (0.67–10.29) (in μg L−1) were found in higher amounts than for the rest of metals. Labile concentrations of metals are related with their downstream proximity to gold mining activities, being higher in devices deployed close to ASGM sites. Moreover, this study demonstrates the feasibility of the DGT technique to sample, transport, storage, and preserve labile Hg from hard-to-reach ASGM areas.

Geospatial Tools for Suitable Assessment of Small Holder Irrigation Water, towards Increased Food Production and Poverty Eradicationin Nigeria: A Case of Jos East LGA. Plateau State

Irrigation is very crucial for sustaining global food security and poverty reduction, especially during off season food production in developing countries. Plateau state in recent years is exploring extensive irrigation schemes to meet up overwhelming national demands of exotic temperate crops and vegetables. The local farmers relyon seasonal streams and abandoned mine ponds for irrigating their crops, but water in these sources are exhausted easily, leading to increased yield losses. This research explores geoinformation methods to map, select and quantify suitable areas to site reservoirs for sustainable Small Holder Irrigation in Jos East LGA of Plateau state as a case study. Spatial Multi Criteria Analysis (SMCA) and other quantitative tools were employed for the spatial modeling and subsequent analysis. The results revealed that 11 sites are highly suitable in Jos East. Volumetric analysis was carried out to estimate potential water collection capabilities of these reservoirs, and the water prospect is estimated between ~172,660 m3 to ~13,929,275 m3, this was based on the calculated depth, and surface area of the prospective reservoirs. Subsequently, this model can be replicated in other parts of Plateau state, Nigeria and Africa with similar environmental, climatic conditions and water demands. We propose small reservoirs with simple engineering techniques to serve poor local communities in developing countries, which can alleviate poverty and enhance sustainable agricultural production. The initiative is in line with FAO’s and World Bank’s programs and recommendations, and which can promote pragmatic solutions and guide project allocations in line with Sustainable Development Goals (SDGs).

Assessment of Heavy Metals in Water and Fish Samples of Abandoned Mining Ponds in Barkin Ladi, Plateau State, Nigeria

Assessment of Heavy Metals in Water and Fish Samples of Abandoned Mining Ponds in Barkin Ladi, Plateau State, Nigeria

Use of multivariable and redundancy analysis to assess the behavior of metals and arsenic in urban soil and road dust affected by metallic mining as a base for risk assessment

The vicinity of abandoned mining ponds to populated areas may suppose a high environmental and health risk being necessary evaluate unreclaimed ponds as source of metal(loid)s. In order to evaluate the behaviour of metals and arsenic from tailing ponds and their effects in urban areas, 10 mine wastes samples, 10 urban soil and 10 urban road dust samples were collected from two mining districts (La Unión and Mazarrón, SE Spain). Physicochemical properties and total, available and water-soluble concentration of metals (Cd, Co, Cr, Cu, Fe, Ni, Mn, Pb, Zn) and As were analyzed. Results suggest enrichment in Fe, Mn, Pb and Zn of urban soil and road dust in both studied towns. Multivariable analysis indicated that Cd, Mn, Pb and Zn in La Unión urban soil, and As, Cd, Cu, Pb and Zn in soil and Fe in road dust of Mazarrón come from mining districts. In addition, redundancy analysis showed that mobility of metal(loid)s related to mining sources were more influenced by their total concentration, while metals with a lithogeny origin were more affected by physicochemical properties.

Assessing the Ecological Effects of Mining in West Africa: The Case of Nigeria

Nigeria’s abundant solid minerals constitute some of the largest known deposits in recent years under different categories. With the activities in the sector characterized by production and a growing environmental decline often overlooked. This research uses a mix scale approach of descriptive statistics and GIS methodology in analyzing the ecological impacts of mining in Nigeria. Emphases are on the issues, environmental and spatial analysis of the trends, factors associated with the issues and current efforts. The results not only reveal large deposits and changes in production, Nigeria’s mineral deposits showed continual growth much of the time despite a few declines. From a -16.98% drop in 2010-2011, aluminium deposits rose by 22.64-63.08% in 2008 to 2009 and the other years. With time, Illegal mining in Pandogari, Niger state stretched through a 17.5 km2-130 km2 radius from 1992 to 1998. By the year 2000, mining operations extended further into a vast area measuring 200 km2 and continued in 2004-2006 with more incursions onto 254-312 km2. The heavy toll of mining on the environment comes with the declines in forest land area in Bukuru, Plateau state where forest area of 420.52 km2 in 1975 fell to 399.56 km2 by 1986. The downward slide continued almost 20 years after in 2005 with only 155.63 km2 area left with green cover. The other burden of pollution risks involves the 1,000 abandoned mine ponds, alongside 1,100-4,000 tin and columbite mines left behind from the mining booms of past eras in the 1960s and spread all over Jos, Plateau. These threats are compounded further by the 400 fatalities from lead poisoning triggered by illegal quarrying in Zamfara in 2010. The GIS mapping of the trends showed clusters of areas prone to hazards and the dispersion of solid mineral potentials in the nation with the impacts linked to socio-economic elements. For mitigation, the study offered suggestions ranging from education to regular assessment of ecological liabilities and the need for policy enhancement.

Hybrid off-river augmentation system as an alternative raw water resource: the hydrogeochemistry of abandoned mining ponds

The use of water from abandoned mining ponds under a hybrid off-river augmentation system (HORAS) has been initiated as an alternative water resource for raw water. However, it raises the questions over the safety of the use of such waters. In this study, the hydrogeochemical analysis of the waters is presented to assess the degree to which the water has been contaminated. Comparisons were made between sampling sites, i.e. abandoned mining ponds, active sand mining ponds and the receiving streams within Bestari Jaya, Selangor River basin. The aqueous geochemistry analysis showed different hydrochemical signatures of major elements between sites, indicating different sources of minerals in the water. Discharges from the sand mining ponds were found to contain elevated availability of dissolved concentrations of iron, manganese, lead, copper and zinc, among others. However, the quality of the water (from the main river) that is supplied for potable water consumption is at a satisfactory level despite being partly sourced from the abandoned mining ponds. In fact, all the metal concentrations detected were well below the Malaysia Ministry of Health guideline limits for untreated raw water. In addition, the results of the geochemical index analysis (i.e. geoaccumulation index, enrichment factor and modified contamination factor) showed that the rivers and abandoned mining ponds were generally unpolluted with respect to the metals found in sediments.

Comparing Heavy Metal Mobility in Active and Abandoned Mining Sites at Bestari Jaya, Selangor

Recent issues on water scarcity have become major public concerns due to availability of safe potable water. The use of abandoned mining ponds as an alternative source of raw water supply has been recently initiated by the Selangor state water authority. This study investigates the potential mobility of heavy metals in both active and abandoned mining ponds at Bestari Jaya ex-mining area. The concentrations of heavy metals in abandoned mining ponds were below the Malaysian Ministry of Health allowable limits. Fe and Mn were found at concentrations above the limits of the Ministry of Health standards for raw water quality (2000) at the active sand mining area. There was an inverse relation between Fe and Mn in water and in sediment as pH changed. The concentration of heavy metals in water and sediment were Fe>Mn>Zn>Pb>Cu.

Distribution of Heavy Metals in Surface and Ground Water in Mkpuma Akpatakpa and Environs

The inhabitants of Mkpuma Akpatakpa have resorted to the usage of water accumulated in the abandoned mine ponds and boreholes due to inadequate potable water within the area. Lead Zinc deposit which is typical of the Benue Trough has been mined within the area, leaving heaps of mine tailings at the site. A total of seven (7) water samples were collected and geochemically analyzed with the main objective of assessing their distribution in the waters of the study area. The results revealed the concentration of Arsenic to be high in both surface and groundwater ranging from 0.1 to 0.492mg/l. which exceeds the WHO limit for portable water. Constant exposure to Potentially Harmful Elements (PHEs) such as lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), and arsenic (As) have shown to have cumulative effects on human health since there is no homeostatic mechanism which can operate to regulate their toxicity. Heavy metals are released into the environment by natural and anthropogenic processes and these increase their concentration, hence leading to pollution. As the populace continues to be exposed to such hazardous element in their drinking water, the health implication could be prevalent overtime if not arrested.

Implications of human exposure to potentially harmful elements from abandoned mine ponds around Barkin-Ladi, Nigeria

The objective of this study was to determine the suitability of mine ponds for drinking and their potential risks on human health in Barkin-Ladi, Nigeria. Potentially harmful elements (PHEs) and radionuclides were analyzed in 20 mine ponds by use of inductive plasma mass spectroscopy (ICP-MS). The data were subjected to principal component analysis (PCA) and factor analysis (FA). Cobalt concentration in the ponds was within the World Health Organization (WHO) allowable limit for drinking water. Lead, arsenic, chromium and uranium concentrations exceeded the WHO allowable limit for drinking water. Chromium and cobalt showed positive loadings in factor 1, with a total variance of 31.12% while lead and arsenic showed positive loadings in factor 2, with a total variance of 26.40%. The presence of virtually all the PHEs and radionuclides above their desirable limits for drinking water in these sampled ponds impaired their quality for drinking purpose. Continuous use of these ponds could lead to incidences of chemical poisoning, cancers and gastro-intestinal diseases among the inhabitants of this community. However, it is advisable that the inhabitants should seek an alternative source of water supply such as groundwater or supply from the Municipality.

Reclamation of Abandoned Mined-Out Areas of BUKURURAYFIELD

The Plateau tin fields have been subjected to mining activities and environmental degradation which spanned over a decade since mining started in 1902. Mining though an indispensable economic activity requires affective management, monitoring and control to forestall undesirable environmental degradation- This was not considered during the first 46 years of mining by the colonial government leading to the devastation of a substantial arable land. This paper examines the reclamation needs of tin fields of the Bukuru-Rayfield environs, and proposes necessary land reclamation methods and major land reclamation machineries and practice that would ensure proper management of mined-out areas and reduce risks of further environmental degradation. The study reveals that of the 9(nine) existing abandoned mine ponds and 5(five) mining spoils a total of about 22,237,380 m3 of earth material would be required for reclamation. This volume includes 435780 m3 of the available mining spoil. This therefore suggests that earth material would have to be moved from the several abandoned spoils of the Plateau tin fields to achieve a sustainable reclamation of the ponds. The study area which falls within the Jos-Bukuru Complex of the Younger Granites Province of the Jos Plateau was subjected to detailed geological investigation as part of initial surveys covering about 30km², between latitudes 9˚ 47' 58.3" and 9˚ 50' 43.6" North and longitudes 8˚ 51' 49.66" and 8˚ 55' 6.03" East (Sheet 168 Naraguta NE).

Application of electrical resistivity tomography to the environmental characterization of abandoned massive sulphide mine ponds (Iberian Pyrite Belt, SW Spain)

ABSTRACTMining activity in the Iberian Pyrite Belt, on the south‐west of the Iberian Peninsula, has generated a great amount of mine tailing ponds, which once the extractive activity is finished, are abandoned and become a serious environmental problem. Here we present the results of applying the electrical resistivity tomography (ERT) technique to characterize the abandoned mine ponds in two sites: Monte Romero and Mina Concepción. ERT has allowed us to determine both the general geometry of the pond’s base and the maximum thickness of the mine tailings. In all cases, the resistivity contrast between the infilling and the bedrock is high enough to clearly define the bottom pond boundary. The low‐resistivity values (lower than ) obtained for the infilling are explained by the high concentration of pyrite in the tailings and the occurrence of acid waters. Whereas the Monte Romero mine pond is almost completely saturated with water, in Mina Concepción it has been possible to identify the presence of inner acid water flows, the outlet of which through the damaged dyke originates a spilling of acid waters to the Odiel River. No low‐resistivity water flows through the base of the ponds into the bedrock have been observed, indicating a good isolation of the base of the studied mine ponds.