Bio-availability and Bio-accessibility of Lead and Zinc in Contaminated Soil from Cwymystwyth Lead Mine Site

Cwmystwyth Lead Mine was an abundant mine site with pugh’s and kingside water drainages shows contaminated water in the research area with no much scientific evidence to ascertain the level of the pollution. Hence this research was designed to study level of lead and zinc in contaminated soil in which the bio-availability and bio-accessibility were measured. Sixteen (16) soil samples were taken at random using soil auger and a hand trowel. The samples were dried using an oven set at a constant temperature of 400oC for 72 hours. Wire mesh (250 microns) was used to sift the samples. The Unified (BARGE) method was used. The mimics mixtures of saliva, gastric, duodenal, and bile fluids. Three-stage mimic processes were performed, in the mouth, the stomach and intestinal cavities. All mimic digestive fluids were placed in the rotator water bath for 1hr at 37oC. The bioaccessibility of the soil Samples were analyzed by inductively coupled plasma-optical emission spectrophotometer (ICP-OES) method. The results were obtained using XRF and ICP methods. The percentage concentration of lead in the topsoil was 0.64% and in the bottom soil was 1.47%, with a total mean concentration of 1.06% in combined top and bottom soil. Zinc concentrations in the top and bottom soils were 0.22 and 0.45%, respectively, with a computed total mean of 0.34%. The findings revealed a highly significant difference between lead and zinc in both the top and bottom soil samples (LSD = P0.05). The average concentrations of lead and zinc extracted in both the stomach and intestinal stages were 15.98% and 1.23%, respectively

Stockpiling disrupts the biological integrity of topsoil for ecological restoration

Purpose Biotic and abiotic properties of soils can hinder or facilitate ecological restoration, and management practices that impact edaphic factors can strongly influence plant growth and restoration outcomes. Salvaged topsoil is an invaluable resource for mine-site restoration, and a common practice is topsoil transfer from mined areas to restoration sites. However, direct transfer is often not feasible, necessitating storage in stockpiles. We evaluated the effects of topsoil stockpiling on plant performance across diverse ecosystems impacted by mining throughout Western Australia. Methods We conducted a bioassay experiment using a widespread native Acacia species to assess how topsoil storage might impact plant growth, physiology, and nodulation by N-fixing bacteria using soils from native reference vegetation and stockpiled soils from six mine sites across Western Australia. Results Plant responses varied across mine sites, but overall plants performed better in soils collected from native vegetation, exhibiting greater biomass, more root nodules, and higher water-use efficiency compared to those grown in stockpiled soils. Soil physiochemistry showed few and minor differences between native soils and stockpiles. Conclusion Results strongly suggest observed differences in plant performance were biotic in nature. This study highlights the negative effects of topsoil storage on the biological integrity of soil across diverse ecosystems, with important implications for mine-site restoration; our results show that topsoil management can strongly influence plant performance, and stockpiled soils are likely inferior to recently disturbed topsoil for restoration purposes. We also use this study to illustrate the utility of bioassays for assessing soil quality for ecological restoration.

Ventilation Design Modeling and Optimization for an Underground Bauxite Mine

Underground bauxite mining exploitation is a challenging environment for ventilation. In this paper, such a complex underground ventilation network is modeled in detail using the Ventsim software. The network and its characteristics are selected and developed through the software, followed by their calibration and validation against actual measurements of both airflow quantity and quality which have been carried out at the mine site. This model constitutes the base of the new ventilation design for the future mine expansion. The recommendations and the characteristics for the optimization of the new proposed design are finally presented in detail.

Reclamation of the Enugu Coal Mine Site at Abandonment

Mining of coal (fossil fuel) resources in Enugu resulted in groundwater pollution/depletion and left the mine site with the potentials of air pollution, loss of landscape/aesthetic degradation and soil contamination. Other Environmental impacts were extensive soil damage, alteration in microbial communities and affecting vegetation leading to destruction of vast amounts of land and displacement of dwellers. Reclamation is the process to restore the ecological integrity of these disturbed mine land areas. It includes the management of all types of physical, chemical and biological disturbances of soils such as soil pH, fertility, microbial community and various soil nutrient cycles that makes the degraded land soil productive. Mining does not mean permanent loss of land for other use. On the other hand it holds potential for altered and improved use apart from restoring for agriculture, forestry and irrigation. This paper attempts to view the best practices for reclaiming the abandoned Enugu coal mine site which ceased production since 2002.

Reclamation of the Enugu Coal Mine Site at Abandonment

Mining of coal (fossil fuel) resources in Enugu resulted in groundwater pollution/depletion and left the mine site with the potentials of air pollution, loss of landscape/aesthetic degradation and soil contamination. Other Environmental impacts were extensive soil damage, alteration in microbial communities and affecting vegetation leading to destruction of vast amounts of land and displacement of dwellers. Reclamation is the process to restore the ecological integrity of these disturbed mine land areas. It includes the management of all types of physical, chemical and biological disturbances of soils such as soil pH, fertility, microbial community and various soil nutrient cycles that makes the degraded land soil productive. Mining does not mean permanent loss of land for other use. On the other hand it holds potential for altered and improved use apart from restoring for agriculture, forestry and irrigation. This paper attempts to view the best practices for reclaiming the abandoned Enugu coal mine site which ceased production since 2002.

Geochemical Baseline and Contamination Level Assessment of Antimony (Sb) in Sediment around Agbaou Gold Mine, Côte d’Ivoire

Agbaou is one of the most recent gold mine exploitation sites in Côte d’Ivoire. Little studies are discussed on the geochemical baseline concentration of trace metals in the wetland sediments around Agbaou gold mine. The main objectives of this study were to establish geochemical baseline values and to assess the pollution status of antimony (Sb). The geochemical baseline concentration of Sb (GBCSb) was estimated using linear regression method. In this study, total Sb concentration was analysed in sediment (10 sediment samples) collected around Agbaou gold mine site. The average Sb concentration was 5.63 ± 2.50 µg.g-1 ranging from 2.50 to 11.3 µg.g-1. The spatial distribution of Sb showed a tendency to accumulate near gold mine site. Moreover, the GBCSb (5.72 µg.g-1) was slightly higher than the average concentration found in sediments. GBC of Sb was used to calculate the anthropogenic contribution rate (R) which exhibited a positive value (R > 0) for all samples, indicating that the sediments were influenced by gold mining activities. Due to lack of local baseline value in the study area, the GBCSb obtained could be used as reference value for Sb contamination level assessment in the sediments.