Mining industry and sustainable development: time for change

Qualitative analysis as a tool for reducing investment risks in post-mining areas located in urban structures

Urban development is not a process of even and planned progression on residential-industrial sites. Enclaves of high-standard space separate degraded and abandoned areas after industrial use has ended. The idea of the compact city is challenged by the need to search for niches for possible development and even to respond to crisis situations. Changing the approach to postmining sites located inside urban spaces generates an alternative to urban sprawl and the squandering of the stock of fertile suburban agricultural land. The aim of this article is to draw attention to the urban presence of postmining sites, to take a systemic view of ways to identify and describe their specific elements and to determine their impact, from the perspective of different user groups, on the quality of space. This research combined expert knowledge and the practical experience of users to create a model for a multilevel audit of postmining spaces. Knowledge about the postmining environment was transferred to landscape and urban design, creating a universal tool for developing strategies to increase the standard utilitarian functions of revitalized postmining areas. This tool will be useful at an early stage of urban development, management and planning.

Magnetic superhydrophobic cellulose nanofibril based aerogel with rope-ladder like structure incorporating both superelasticity and excellent oil absorption

Achieving an equilibrium between exceptional oil absorption and remarkable elasticity has emerged as a formidable challenge for magnetic porous materials designed for oil absorption. Here, we propose an original, magnetic and superhydrophobic cellulose nanofibril (CNF) based aerogel system with a rope-ladder like skeleton by to greatly improve the issue. Within this system, CNF as the skeleton was combined with multiwalled carbon nanotubes (MWCNT)@Fe3O4 as the magnetic and enhanced component, both methyltrimethoxysilane (MTMS) and acetonitrile-extracted lignin (AEL) as the soft-hard associating constituents. The resultant CNF based aerogel shows a rope-ladder like pore structure to contribute to high elasticity and excellent oil absorption (28.34-61.09 g/g for various oils and organic solvents) under the synergistic effect of Fe3O4@MWCNT, AEL and MTMS, as well as good specific surface area (27.97 m2/g), low density (26.4 mg/cm3). Notably, despite the introduced considerable proportion (0.5 times of mass-CNF) of Fe3O4@MWCNT, the aerogel retained an impressive compression-decompression rate (88%) and the oil absorption efficiency of above 87% for various oils due to the soft-hard associating structure supported by both MTMS and AEL. This study provides a prospective strategy to balance between high elasticity and excellent oil absorption of CNF based aerogel doping inorganic particles.

Impacts of mining on vegetation phenology and sensitivity assessment of spectral vegetation indices to mining activities in arid/semi-arid areas

Measuring the impact of mining activities on vegetation phenology and assessing the sensitivity of vegetation indices (VIs) to it are crucial for understanding land degradation in mining areas and enhancing the carbon sink capacity following the ecological restoration of mines. To this end, we have developed a novel technical framework to quantify the impact of mining activities on vegetation, and applied it to the Bainaimiao copper mining area in Inner Mongolia. Phenological indices are extracted based on the VI time series data of Sentinel-2, and changes in phenological differences in various directions are used to quantify the impact of mining activities on vegetation. Finally, indicators such as mean difference, standard deviation, index value distribution interval, and concentration of index value distribution were selected to assess the sensitivity of the Enhanced Vegetation Index (EVI), Green Chlorophyll Index (GCI), Global Environmental Monitoring Index (GEMI), Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Vegetation Index (NDVI), Renormalized Difference Vegetation Index (RDVI), Red-Edge Chlorophyll Index (RECI), and Soil-Adjusted Vegetation Index (SAVI) to mining activities. The results of the study show that the impact of mining activities on surrounding vegetation extends to an area three times larger than the actual mining activity area. When compared with the reference and unaffected areas, the affected area experienced a delay of approximately 10 days in seasonal vegetation development. Environmental pollution caused by the tailings pond was identified as the primary factor influencing this delay. Significant variations in the sensitivity of each VI to assess mining activities in arid/semi-arid areas were observed. Notably, GCI, GNDVI and RDVI displayed relatively high sensitivity to discrepancies in the spectral attributes of vegetation within the affected area, while SAVI reflected the overall spectral stability of the vegetation in the affected area. The research findings have the potential to provide valuable technical guidance for holistic environmental management in mining areas and hold great significance in preventing further land degradation and supporting ecological restoration in mining areas.

Cadmium tolerance in tomato: determination of organ-specific contribution by diallel analysis using reciprocal grafts

Given the increasing problems of water and soil contamination with cadmium (Cd), it is necessary to investigate the genetic and physiological mechanisms of tolerance to this metal in different crops, which can be used for the development of effective crop management strategies. This study aimed to assess the potential of grafting as a strategy to increase Cd tolerance and reduce absorption in tomato by evaluating the contribution of the root system and aerial parts for tolerance mechanisms. To this end, reciprocal grafting and diallel analyses were used to examine the combining ability of contrasting tomato genotypes under exposure to 0 and 35 µM CdCl2. Roots and above-ground parts were found to have specific mechanisms of Cd tolerance, absorption, and accumulation. Grafting of the USP15 genotype (scion) on USP16 (rootstock) provided the greatest synergism, increasing the tolerance index and reducing the translocation index and Cd accumulation in leaves. USP163 exhibited potential for breeding programs that target genotypes with high Cd tolerance. In tomato, both Cd tolerance and accumulation in aerial parts are genotype- and tissue-specific, controlled by a complex system of complementary mechanisms that need to be better understood to support the development of strategies to reduce Cd contamination in aerial parts.

Sources and controls of greenhouse gases and heavy metals in mine water: A continuing climate legacy

Water pollution arising from abandoned coal mines, is second only to sewage as a source of freshwater pollution and in coalfield catchments mine water can be the dominant pollutant, with oxidised iron smothering the bed of receiving rivers. This study measured greenhouse gases in mine water outflows from sixteen sites across the Midland Valley in Scotland. Radiogenic and stable carbon isotopes measurements (Δ14C and δ13C) were used to determine the sources of both methane (CH4) and carbon dioxide (CO2) produced within the flooded mine environment. Concentrations of CH4-C ranged from 20 to 215 μg l-1 and CO2-C from 30 to 120 mg l-1, with CO2 accounting for 97 % of the mine water global warming potential. Methane origins included 51 % modern biogenic, 41 % thermogenic and 8 % from hydrogenotrophic methanogenesis of coal. The most significant inverse impact on biogenic CH4 concentrations was sulphate, most likely due to sulphate reducing bacteria outcompeting methanogens. Carbon dioxide origins included 64 % from the dissolution of limestone, 21 % from terrestrial organic carbon and 15 % from coal. The limestone derived CO2 was positively correlated with high sulphate concentrations, which resulted in sulphuric acid and caused the dissolution of carbonate from limestone. The mine waters experienced significant carbonate buffering becoming only slightly acidic (pH 6-7), but with significant loss of inorganic carbon. The mine waters had low dissolved oxygen (6-25 %) and high dissolved iron (2 to 65 mg l-1) and manganese (0.5 to 5 mg l-1) concentrations. Dissolved greenhouse gases from abandoned mines were estimated as 0.27 +0.31-0.18% of Scotland's global warming potential. This novel work has contributed information about the sources and controls of greenhouse gas fluxes in mine waters and identified the need to quantify and report this emissions term.

Spatial evolution and decomposition of energy-related CO2 emissions in China's mining industry: from the perspective of regional heterogeneity

To ensure China's energy security, the mining industry faces increasing emissions reduction and energy conservation pressures. This study combined index and production-theoretical decomposition analyses to decompose the energy-related CO2 emissions in mining industry (ERCEMI) influencing factors into seven major effects and adopted a gravity model to dynamically visualize the transfer path and gravity distribution from 2000 to 2015. As investment effects were introduced into the decomposition analysis, the results fully considered the regional heterogeneity and spatiotemporal dynamics. The main findings were as follows: (i) a typical heavy emissions trend along the Heihe-Tengchong line, with a concentration of large ERCEMI values; (ii) the gravity center of ERCEMI had shifted to the southwest, and the migration trends were divided into three stages; (iii) the ERCEMI had strong regional heterogeneity, with a diffusion trend from north to south and shrinking from east to west; (iv) the potential energy intensity and investment efficiency effects had significantly inhibited the ERCEMI, while the investment scale had boosted it. Implications for regional layouts, energy intensity reductions, and investment optimization are discussed. This research provides a comprehensive regional analysis for ERCEMI reductions and the sustainable development of the mining industry and provides a reference for local industrial development planning.

Impact of coexisting components in acid mine drainage on Sb(Ⅲ) oxidation by biosynthesized iron nanoparticles

Despite the oxidation mechanism of antimonite (Sb(Ⅲ)) by biosynthesized iron nanoparticles (Fe NPs) has been reported, the impact of coexisting components in acid mine drainage (AMD) on the Sb(III) oxidation by Fe NPs is unknown. Herein, how the coexisting components in AMD affect Sb(Ⅲ) oxidation by Fe NPs was investigated. Firstly, Fe NPs achieved complete oxidation of Sb(Ⅲ) (100%), while only 65.0% of Sb(Ⅲ) was oxidized when As(Ⅲ) was added, due to competitive oxidation between As(Ⅲ) and Sb(Ⅲ), which was verified by characterization analysis. Secondly, the decline in solution pH improved Sb(Ⅲ) oxidation from 69.5% (pH 4) to 100% (pH 2), which could be attributed to the rise of Fe³⁺ in solution promoting the electron transfer between Sb(Ⅲ) and Fe NPs. Thirdly, the oxidation efficiencies of Sb(Ⅲ) fell by 14.9 and 44.2% following the addition of oxalic and citric acid, respectively, resulting from the fact that these two acids reduced the redox potential of Fe NPs, thereby inhibiting Sb(Ⅲ) oxidation by Fe NPs. Finally, the interference effect of coexisting ions was studied, where PO₄^3- significantly reduced Sb(Ⅲ) oxidation efficiency due to the occupation of the surface-active sites on Fe NPs. Overall, this study has significant implications for the prevention of Sb contamination in AMD.

Fungal community remediate quartz tailings soil under plant combined with urban sludge treatments

Introduction

Tailings can cause extensive damage to soil structure and microbial community. Phytoremediation is an effective strategy for remedied tailings soil due to its environmentally friendly and low-cost advantage. Fungi play a crucial role in nutrient cycling, stress resistance, stabilizing soil structure, and promoting plant growth. However, the fungal community variation in phytoremediation remains largely unexplored.

Methods

We analyzed soil fungal community based on high-throughput sequencing during three plant species combined with urban sludge to remediate quartz tailings soil.

Results

The results indicated that the fungal diversity was significantly increased with plant diversity, and the highest fungal diversity was in the three plant species combination treatments. Moreover, the fungal diversity was significantly decreased with the addition of urban sludge compared with plant treatments, while the abundance of potential beneficial fungi such as Cutaneotrichosporon, Apiotrichum, and Alternaria were increased. Notably, the fungal community composition in different plant species combination treatments were significant difference at the genus level. The addition of urban sludge increased pH, available phosphorus (AP), and available nitrogen (AN) content that were the main drivers for fungal community composition. Furthermore, the fungal networks of the plant treatments had more nodes and edges, higher connectedness, and lower modularity than plant combined with urban sludge treatments.

Conclusion

Our results showed that three plant species combined with urban sludge treatments improved fungal community and soil properties. Our results provide insights for quartz tailings soil remediation using plant-fungi- urban sludge.

Geo-environmental factors' influence on mining operation: an indirect effect of managerial factors

The purpose of the paper is to identify factors associated with operational factor (OF), geo-environmental factor (GEF), and managerial factor (MF) from the literature. After identification, the study intended to assess the impact of geo-environmental factors and managerial factors on operational factors of the mining industry. The study also tests the indirect effect of managerial factors between GEF and OF in the Indian environment. The geographical boundary of the study was 06 large mines of Odisha, Jharkhand, and Chhattisgarh of India. Three hundred and twenty nine number of purposive samples were collected via email and filtered and processed through the SPSS package. To find out the complex role and inter-relationship of GEF and MF on OF, the study adopted the structural equation modelling technique. The finding reflects that MF plays a partial mediation among GEF and OF. This phenomenon is completely novel in its field when it comes to the geo-environmental and management difficulties confronting mining operations. This research can aid managers in identifying key geological and environmental concerns in mining operations, as well as providing data for regulatory compliance. Overall, this study's findings can help management create policies and manage the environmental concerns of the mining sector. The study's findings provide important directions for future Indian mining research.

Acidophilic microorganisms in remediation of contaminants present in extremely acidic conditions

Acidophiles are a group of microorganisms that thrive in acidic environments where pH level is far below the neutral value 7.0. They belong to a larger family called extremophiles, which is a group that thrives in various extreme environmental conditions which are normally inhospitable to other organisms. Several human activities such as mining, construction and other industrial processes release highly acidic effluents and wastes into the environment. Those acidic wastes and wastewaters contain different types of pollutants such as heavy metals, radioactive, and organic, whose have adverse effects on human being as well as on other living organisms. To protect the whole ecosystem, those pollutants containing effluents or wastes must be clean properly before releasing into environment. Physicochemical cleanup processes under extremely acidic conditions are not always successful due to high cost and release of toxic byproducts. While in case of biological methods, except acidophiles, no other microorganisms cannot survive in highly acidic conditions. Therefore, acidophiles can be a good choice for remediation of different types of contaminants present in acidic conditions. In this review article, various roles of acidophilic microorganisms responsible for removing heavy metals and radioactive pollutants from acidic environments were discussed. Bioremediation of various acidic organic pollutants by using acidophiles was also studied. Overall, this review could be helpful to extend our knowledge as well as to do further relevant novel studies in the field of acidic pollutants remediation by applying acidophilic microorganisms.

Assisted Phytostabilization of Mine-Tailings with Prosopis laevigata (Fabaceae) and Biochar

Phytoremediation is a cost-effective technique to remediate heavy metal (HM) polluted sites. However, the toxic effects of HM can limit plant establishment and development, reducing phytoremediation effectiveness. Therefore, the addition of organic amendments to mine wastes, such as biochar, improves the establishment of plants and reduces the bioavailability of toxic HM and its subsequent absorption by plants. Prosopis laevigata can establish naturally in mine tailings and accumulate different HM; however, these individuals show morphological and genetic damage. In this study, the effect of biochar on HM bioaccumulation in roots and aerial tissues, HM translocation, morphological characters and plant growth were evaluated, after three and six months of exposure. Plants grown on mine tailings with biochar presented significantly higher values for most of the evaluated characters, in respect to plants that grew on mine tailing substrate. Biochar addition reduced the bioaccumulation and translocation of Cu, Pb, and Cd, while it favored the translocation of essential metals such as Fe and Mn. The addition of biochar from agro-industrial residues to mine tailings improves the establishment of plants with potential to phytoextract and phytostabilize metals from polluted soils. Using biochar and heavy metal accumulating plants constitutes an assisted phytostabilization strategy with great potential for HM polluted sites such as Cd and Pb.

Activity concentrations and radiological hazard assessments of 226Ra, 232Th, and 40K in soil samples of oil-producing areas of South Africa

The specific activity of natural radionuclide in soil samples of the oil-producing areas of South Africa was measured using a High Purity Germanium detector. The activity of226Ra, 232Th, and 40K in the soil range from 16.5 ± 1.3 to 64.9 ± 3.1, 16.8 ± 1.5 to 88.6 ± 1.2, 135.2 ± 17.5 to 604.8 ± 13.4 Bqkg-1 for Mossel Bay; 14.3 ± 1.2 to 48.9 ± 8.2, 22.3 ± 1.4 to 45.1 ± 3.2, 237.7 ± 10.9 to 486.5 ± 40.1 Bqkg-1 for Cape Town; 10.5 ± 1.1 to 25.8 ± 3.2, 13.1 ± 1.9 to 44.3 ± 5.2, 140.2 ± 10.9 to 229.8 ± 12.8 Bqkg-1 for Nelson Mandela Bay and 5.6 ± 2.2 to 13.1 ± 2.9, 4.5 ± 2.5 to 14.1 ± 2.7, 62.7 ± 22.6 to 126.5 ± 21.2 Bqkg-1 for Msunduzi. Most soil samples' radiological hazards were within the world average.

Environmental behavior, human health effect, and pollution control of heavy metal(loid)s toward full life cycle processes

Heavy metal(loid)s (HMs) have caused serious environmental pollution and health risks. Although the past few years have witnessed the achievements of studies on environmental behavior of HMs, the related toxicity mechanisms, and pollution control, their relationship remains a mystery. Researchers generally focused on one topic independently without comprehensive considerations due to the knowledge gap between environmental science and human health. Indeed, the full life cycle control of HMs is crucial and should be reconsidered with the combination of the occurrence, transport, and fate of HMs in the environment. Therefore, we started by reviewing the environmental behaviors of HMs which are affected by a variety of natural factors as well as their physicochemical properties. Furthermore, the related toxicity mechanisms were discussed according to exposure route, toxicity mechanism, and adverse consequences. In addition, the current state-of-the-art of available technologies for pollution control of HMs wastewater and solid wastes were summarized. Finally, based on the research trend, we proposed that advanced in-operando characterizations will help us better understand the fundamental reaction mechanisms, and big data analysis approaches will aid in establishing the prediction model for risk management.

Using the ISM-ANP-SD combination model to explore the mechanism and intervention strategies of influencing factors of coal mine safety system

Background

With the intelligent construction of coal mines, the number of coal mine accidents is gradually decreasing, but the complexity of accidents is increasing. Understanding the interaction mechanism among the influencing factors of the coal mine safety system is an essential part of improving and enhancing the safety of the coal mine system.

Methods

The descriptive, structural model-network hierarchical analysis (ISM-ANP) was used to explore the interaction between the factors influencing the coal mine safety system and determine each factor's importance. A system dynamics simulation model was constructed to clarify the mechanism of each factor's effect on the safety system.

Results

The results show that Individual miners' factors directly influence coal mine system safety, organizational management factors, and group factors indirectly influence system safety and play the role of macro regulation. The intelligent system is the most profound factor influencing system safety. There are apparent differences in the influence of different subsystems on system safety, with organizational management having the most significant influence on system safety, followed by individual miners and group factors, and intelligent system factors and external environmental factors having a more negligible influence on system safety.

Conclusion

There is a complex interaction between the factors affecting the safety of the coal mine system, and there are apparent differences in the influence of different subsystems on the safety level of the coal mine system. This study puts forward the intervention strategy to improve the safety of the coal mine system, which provides theoretical support and method guidance for preventing coal mine accidents and improving the safety level of the coal mine system.

Sensitivity of Pathogenic Bacteria Strains to Treated Mine Water

Mine water as a result of meteoric and/or underground water's contact with tailings and underground workings could have an elevated content of metals associated with sulfate, often acidic, due to the bio-oxidation of sulfides. When entering aquatic ecosystems, the mine water can cause significant changes in the species' trophic levels, therefore a treatment is required to adjust the alkalinity and to remove the heavy metals and metalloids. The conventional mine water treatment removes metals, but in many cases it does not reduce the sulfate content. This paper aimed to predict the impact of conventionally treated mine water on the receiving river by assessing the genotoxic activity on an engineered Escherichia coli and by evaluating the toxic effects generated on two Gram-negative bacterial strains, Pseudomonas aeruginosa and Escherichia coli. Although the main chemical impact is the severe increases of calcium and sulfate concentrations, no significant genotoxic characteristics were detected on the Escherichia coli strain and on the cell-viability with a positive survival rate higher than 80%. Pseudomonas aeruginosa was more resistant than Escherichia coli in the presence of 1890 mg SO₄^2-/L. This paper reveals different sensitivities and adaptabilities of pathogenic bacteria to high concentrations of sulfates in mine waters.

Synergies in sustainable phosphorus use and greenhouse gas emissions mitigation in China: Perspectives from the entire supply chain from fertilizer production to agricultural use

Synergies to achieve high phosphorus (P) use efficiency (PUE) and mitigate greenhouse gas (GHG) emissions are critical for developing strategies aimed toward agricultural green development. However, the potential effects of such synergies in the entire P supply chain through optimizing P management in crop production are poorly understood. In this study, a partial life cycle of a GHG emissions model was developed to quantify the P-related GHG emissions in the entire P supply chain in China. Our results showed that 16.3 kg CO₂-equivalent (CO₂-eq) was produced from the entire P supply chain per unit of P used for grain agriculture (maize, rice, and wheat). P-related GHG emissions in China increased more than five-fold from 1980 (7.2 Tg CO₂-eq) to 2018 (44.9 Tg CO₂-eq). GHG emissions were found to be strongly associated with the intensity of grain production in China, and they varied considerably across production regions owing to the differences in the P fertilizer production efficiency. Mineral P fertilizer use in crop production was the primary source of P-related GHG emissions. The results suggest that sustainable P management by matching mineral P fertilizer rates and fertilizer types with crop needs can mitigate GHG emissions by 10.8-27.7 Tg (24.0-65.1%). Moreover, this can improve PUE and reduce mineral P input by 0.7-1.4 Tg (24.0-46.0%). These findings highlight that potential synergies between high PUE and low P-related GHG emissions can be achieved via sustainable P management, thereby enhancing green agricultural development in China and other regions worldwide.

Uncertainty prediction of mining safety production situation

In order to explore the occurrence and development law of mining safety production accidents, analyze its future change trends, and aim at the ambiguity, non-stationarity, and randomness of mining safety production accidents, an uncertainty prediction model for mining safety production situation is proposed. Firstly, the time series effect evaluation function is introduced to determine the optimal time granularity, which is used as the window width of fuzzy information granulation (FIG), and the time series of mining safety production situation is mapped to Low, R, and Up three granular parameter sequences, according to the triangular fuzzy number; then, the mean value of the intrinsic mode function (IMF) is maintained in the normal dynamic filtering range. After the ensemble empirical mode decomposition (EEMD), the three non-stationary granulation parameter sequences of Low, R, and Up are decomposed into the intrinsic mode function components representing the detail information and the trend components representing the overall change, and then the sub-sequences are reconstructed according to the sample entropy to highlight the correlation among the sub-sequences; finally, the cloud model language rules of mining safety production situation prediction are created. Through time series discretization, cloud transformation, concept jump, time series set division, association rule mining, and uncertain reasoning, the reconstructed component sequence is modeled and predicted by uncertainty information extraction. The accuracy of the uncertainty prediction model was verified by 21 sets of test samples. The average relative errors of Low, R, and Up sequences were 9.472 %, 16.671 %, and 3.625 %, respectively. The research shows that the uncertainty prediction model of mining safety production situation overcomes the fuzziness, non-stationarity, and uncertainty of safety production accidents, and provides theoretical reference and practical guidance for mining safety management and decision-making.

An insight on the impact of COVID-19 on the global and Turkish mining industry

BACKGROUND: COVID-19 affected numerous industries and the mining industry has not been immune to the adverse impacts caused by the pandemic. OBJECTIVE: This study examines the importance of the mining industry and its benefits to the economy of the producing countries. The paper also gives an insight into the pre-COVID global and Turkish mining industries and investigates the impact of the pandemic on the global and Turkish mining sectors. Furthermore, the study suggests numerous measures that should be adopted in mines to limit the spread of COVID-19 and conduct mining operations safely and efficiently. METHODS: An extensive literature review was conducted and relevant papers on the importance and benefits of the mining industry, the Turkish and global mining industry, and the impact of COVID-19 on the Turkish and global mining industry were studied. RESULTS: The COVID-19 crisis has deeply affected metal and mineral production and the economic sectors that depend on the mining industry for supplies. The most significant impacts caused by the COVID-19 pandemic on the global mining industry consist of the drastic decline in demand and production and the decrease in the prices of several commodities. As with any complex global situation, the mining industries of some countries were affected more than others by the COVID-19 crisis. The Turkish mining industry was to some extent affected by the COVID-19 crisis, but it quickly recovered. CONCLUSIONS: An efficient planning of operations and adopting effective measures and precautions enable limiting the spread of COVID-19 in quarries and mines.

A Study on the Prediction of Compressive Strength of Self-Compacting Recycled Aggregate Concrete Utilizing Novel Computational Approaches

A considerable amount of discarded building materials are produced each year worldwide, resulting in ecosystem degradation. Self-compacting concrete (SCC) has 60–70% coarse and fine particles in its composition, so replacing this material with another waste material, such as recycled aggregate (RA), reduces the cost of SCC. This study compares novel Artificial Neural Network algorithm techniques—Levenberg–Marquardt (LM), Bayesian regularization (BR), and Scaled Conjugate Gradient Backpropagation (SCGB)—to estimate the 28-day compressive strength (f’c) of SCC with RA. A total of 515 samples were collected from various published papers, randomly splitting into training, validation, and testing with percentages of 70, 10 and 20. Two statistical indicators, correlation coefficient (R) and mean squared error (MSE), were used to assess the models; the greater the R and lower the MSE, the more accurate the algorithm. The findings demonstrate the higher accuracy of the three models. The best result is achieved by BR (R = 0.91 and MSE = 43.755), while the accuracy of LM is nearly the same (R = 0.90 and MSE = 48.14). LM processes the network in a much shorter time than BR. As a result, LM and BR are the best models in forecasting the 28 days f’c of SCC having RA. The sensitivity analysis showed that cement (28.39%) and water (23.47%) are the most critical variables for predicting the 28-day compressive strength of SCC with RA, while coarse aggregate contributes the least (9.23%).

Application of Cement Paste in Mining Works, Environmental Protection, and the Sustainable Development Goals in the Mining Industry

Cement paste is an already well-known material used in ore mining. It is mainly used to fill excavation areas and the tailings from the surface return to underground mines. In this way, the amount of deposited material and degradation of the surface of the terrain are reduced. The paste itself can be used as an artificial barrier between mining works and underground watercourses. Significant economic and environmental benefits can be expected from using cement paste, which would contribute to sustainable development. The basic materials that make up cemented paste backfill (CPB) are flotation tailings, cement, and water. For CPB to be adequately and safely applied to the filling of excavation spaces and indirectly to the protection of the groundwater, environment, and sustainable development of the mining industry, it must meet certain physical–mechanical, physicochemical, and deformation properties. This paper presents the results of synthesized and analyzed samples of different compositions based on flotation tailings (from the production of ZiJin Copper in Bor, Serbia), cement, and water. The methods used for chemical and mineralogical tests include inductively coupled plasma atomic emission spectroscopy (ICP-AES), atomic absorption spectroscopy (AAS), X-ray diffraction analysis (XRD), and nephelometric turbidity units (NTUs; turbidimetry). The results prepared with CPB consisting of 5% cement, 24% water, and 71% flotation tailings were the most acceptable.

Prediction of Splitting Tensile Strength of Self-Compacting Recycled Aggregate Concrete Using Novel Deep Learning Methods

The composition of self-compacting concrete (SCC) contains 60–70% coarse and fine aggregates, which are replaced by construction waste, such as recycled aggregates (RA). However, the complexity of its structure requires a time-consuming mixed design. Currently, many researchers are studying the prediction of concrete properties using soft computing techniques, which will eventually reduce environmental degradation and other material waste. There have been very limited and contradicting studies regarding prediction using different ANN algorithms. This paper aimed to predict the 28-day splitting tensile strength of SCC with RA using the artificial neural network technique by comparing the following algorithms: Levenberg–Marquardt (LM), Bayesian regularization (BR), and Scaled Conjugate Gradient Backpropagation (SCGB). There have been very limited and contradicting studies regarding prediction by using and comparing different ANN algorithms, so a total of 381 samples were collected from various published journals. The input variables were cement, admixture, water, fine and coarse aggregates, and superplasticizer; the data were randomly divided into three sets—training (60%), validation (10%), and testing (30%)—with 10 neurons in the hidden layer. The models were evaluated by the mean squared error (MSE) and correlation coefficient (R). The results indicated that all three models have optimal accuracy; still, BR gave the best performance (R = 0.91 and MSE = 0.2087) compared with LM and SCG. BR was the best model for predicting TS at 28 days for SCC with RA. The sensitivity analysis indicated that cement (30.07%) was the variable that contributed the most to the prediction of TS at 28 days for SCC with RA, and water (2.39%) contributed the least.

Artisanal and Small-Scale Gold Mining (ASGM): Management and Socioenvironmental Impacts in the Northern Amazon of Ecuador

Mining is one of the oldest economic activities of mankind. Within this activity, artisanal and small-scale gold mining (ASGM) is one of the most studied sectors due to its high level of environmental contamination and the social problems it causes. In recent years, ASGM in the northern Amazon of Ecuador has increased significantly, and studies that describe its current situation and impact are scarce. In this sense, the present study aimed to analyze the current status and socioenvironmental impacts caused by ASGM gold mining activities in the Cascales canton in the province of Sucumbíos in northeastern Ecuador. The methodological tools used in the present study were a literature review of scientific and gray literature, field visits to assess perceived impacts and an expert judgment to discuss the results and establish challenges. The main results indicate that illegal and informal activities continue to be carried out in the upper zone of the Cascales and Duvino rivers; 90% of local miners still use mercury in this activity, although it is legally prohibited. Among the main impacts evidenced are the contamination of water bodies, soil and atmosphere due to the use of mercury and disturbance to flora and fauna due to the use of machinery in the exploration process. Finally, the government should focus efforts on strengthening public policies to socialize the importance of good environmental practices in ASGM and the effects of the impacts on human health and environmental issues, all this with the support of social actors, such as ministries, universities, NGOs, ASGM associations and private enterprise.

Radiation exposure in a region with natural high background radiation originated from rare earth element deposits at Bat Xat district, Vietnam

Surface deposits of rare earth element (REE) were identified in the Bat Xat district, Northern Vietnam. As the area is inhabited, an in-depth investigation was carried out to assess the radioactivity levels and to evaluate the radiation exposure and radiological risks for the population. Samples of REE ore, soils, water and several foods locally produced were collected and analyzed by gamma spectrometry for determination of ²³²Th, ²²⁶Ra, and ⁴⁰ K. Radon (²²²Rn and ²²⁰Rn) measurements were carried out in dwellings at the villages located near by the REE deposit area, and in Hanoi for comparison. Based on the measured radionuclide concentrations, several radiological parameters were calculated to evaluate the radiological risks for the population and to compare with worldwide values. Results indicate that the representative person of the most exposed group living near the REE deposits may receive a total annual effective dose as high as 37.9 ± 10.6 mSv, i.e., approximately 16 times the world average dose of 2.4 mSv y^-1. Consequently, this area should be considered a high background radiation area. Exposure to external radiation and internal radiation from ingestion and inhalation of radionuclides were assessed separately. Radon inhalation contributed to approximately 70% of the total annual effective dose, with both radon isotopes contributing significantly, while the ingestion of local foods and water gave minor contributions to the total effective dose. Several measures were considered to improve the radiation safety and recommendations are given to relocate the most exposed members of the population.

Ethical opportunities in deep-sea collection of polymetallic nodules from the Clarion-Clipperton Zone

Infrastructure supporting the transition of human societies from fossil fuels to renewable energy will require hundreds of millions of tons of metals. Polymetallic nodules on the abyssal seabed of the Clarion-Clipperton Zone (CCZ), eastern North Pacific Ocean, could provide them. We focus on ethical considerations and opportunities available to the novel CCZ nodule-collection industry, integrating robust science with strong pillars of social and environmental responsibility. Ethical considerations include harm to sea life and recovery time, but also the value of human life, indigenous rights, rights of nature, animal rights, intrinsic values, and intangible ecosystem services. A "planetary perspective" considers the biosphere, hydrosphere, and atmosphere, extends beyond mineral extraction to a life-cycle view of impacts, and includes local, national, and global impacts and stakeholders. Stakeholders include direct nodule-collection actors, ocean conservationists, companies, communities, interest groups, nations, and citizens globally, plus counterfactual stakeholders involved with or affected by intensification of terrestrial mining if ocean metals are not used. Nodule collection would harm species and portions of ecosystems, but could have lower life-cycle impacts than terrestrial mining expansion, especially if nodule-metal producers explicitly design for it and stakeholders hold them accountable. Participants across the value chain can elevate the role of ethics in strategic objective setting, engineering design optimization, commitments to stakeholders, democratization of governance, and fostering of circular economies. The International Seabed Authority is called to establish equitable and transparent distribution of royalties and gains, and continue engaging scientists, economists, and experts from all spheres in optimizing deep-sea mineral extraction for humans and nature. Nodule collection presents a unique opportunity for an ambitious reset of ecological norms in a nascent industry. Embracing ethical opportunities can set an example for industrial-scale activities on land and sea, accelerate environmental gains through environmental competition with land ores, and hasten civilization's progress toward a sustainable future. Integr Environ Assess Manag 2022;18:634-654. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Understanding changes in biocrust communities following phosphate mining in the Negev Desert

Biocrusts are key ecosystem engineers that are being destroyed due to anthropogenic disturbances such as trampling, agriculture and mining. In hyper-arid regions of the Negev Desert, phosphate has been mined for over six decades, altering the natural landscape over large spatial scales. In recent years, restoration-oriented practices were mandated in mining sites, however, the impact of such practices on the ecosystem, particularly the biocrust layer, has not been tested. Here, we evaluated post-mining biocrust bacterial communities and compared them to undisturbed (reference) biocrusts. We collected samples from four mining sites (each restored at a different year) and their corresponding reference sites. We hypothesized that post-mining bacterial communities would differ significantly from reference communities, given the slow regeneration of the biocrust. We also hypothesized that bacterial communities would vary among post-mining plots based on their restoration age. To test these hypotheses, we assessed the abundance and diversity of bacterial communities by sequencing the 16S rDNA and their photosynthetic potential by quantifying the abundance of cyanobacteria and chlorophyll a. The bacterial diversity was lower, and community composition differed significantly between post-mining and reference biocrusts. In addition, cyanobacteria abundances and chlorophyll a content were lower in post-mining biocrusts, indicating lower photosynthetic potential. However, no significant changes in bacterial communities were detected, regardless of the restoration age. We suggest that the practices implemented in the Negev mines may not support the recovery of the biocrust bacterial communities, particularly the cyanobacteria. Thus, active restoration measures are needed to accelerate the regeneration time of biocrusts at the hyper-arid Negev mines.

Cooperative Projects to Share Good Practices towards More Effective Sustainable Mining—SUGERE: A Case Study

The supply of raw materials is a global challenge to be addressed; themes such as “sustainability”, “responsibility”, and “eco-compatibility” represent the cornerstones for proceeding towards a “wise” management of georesources. According to the United Nations’ SDGs, the economic development of countries must go hand in hand with the improvement of their environmental, health, and social sustainability. From this perspective, the exploitation of georesources needs to be handled with an interdisciplinary approach that tackles not only the technical, economic, and environmental issues, but also the social, legislative, and human health ones. In recent years, Europe has promoted several cooperative projects aimed at boosting sustainability in the extractive industry. To achieve and guarantee concrete and truly sustainable mining, it is necessary to build and strengthen educational and training skills. With these objectives in mind, the first results of the EU–Africa SUGERE Erasmus+ project are presented here. The objects of the project are the implementation of Bachelor, Master, and doctoral curricula in geology and mining engineering and the promotion of socioeconomic development thanks to the training of experts who are able to cooperate and work in an interdisciplinary manner for a sustainable approach to local mine exploitation.

Changes in soil properties during iron mining and in rehabilitating minelands in the Eastern Amazon

Open-cast iron mining causes drastic disturbances in soil properties. Recovery of soil chemical and physical properties is essential for successful revegetation and landscape rehabilitation. To identify changes in soil properties during the mining and revegetation process, soil samples were collected from undisturbed sites represented by forest and ferriferous savannas stocking above iron outcrops, called "cangas," in open-pit benches, and in rehabilitation chronosequences of iron waste piles in the Carajás Mineral Province (CMP), Eastern Amazon, Brazil. The samples were analyzed for chemical and physical properties. Our results showed that iron mining operations resulted in significant alteration of the chemical soil properties when forest and canga vegetation are suppressed to form open-pit benches or waste piles in the CMP. Mining substrates showed lower contents of soil organic matter (SOM) and nutrients than undisturbed areas of forests and cangas. In order to achieve the success of revegetation, nutrients have been added prior to plant establishment. We have demonstrated how soil fertility changes along with mineland rehabilitation, and the variation among chronosequence was attributable mainly due to contents of SOM, K, and B in the soil. The slight improvement of SOM found in rehabilitated waste piles reinforces the notion that recovery of soil quality can be a slow process in iron minelands in the CMP.

Nitrate Water Contamination from Industrial Activities and Complete Denitrification as a Remediation Option

Freshwater is a scarce resource that continues to be at high risk of pollution from anthropogenic activities, requiring remediation in such cases for its continuous use. The agricultural and mining industries extensively use water and nitrogen (N)-dependent products, mainly in fertilizers and explosives, respectively, with their excess accumulating in different water bodies. Although removal of NO3 from water and soil through the application of chemical, physical, and biological methods has been studied globally, these methods seldom yield N2 gas as a desired byproduct for nitrogen cycling. These methods predominantly cause secondary contamination with deposits of chemical waste such as slurry brine, nitrite (NO2), ammonia (NH3), and nitrous oxide (N2O), which are also harmful and fastidious to remove. This review focuses on complete denitrification facilitated by bacteria as a remedial option aimed at producing nitrogen gas as a terminal byproduct. Synergistic interaction of different nitrogen metabolisms from different bacteria is highlighted, with detailed attention to the optimization of their enzymatic activities. A biotechnological approach to mitigating industrial NO3 contamination using indigenous bacteria from wastewater is proposed, holding the prospect of optimizing to the point of complete denitrification. The approach was reviewed and found to be durable, sustainable, cost effective, and environmentally friendly, as opposed to current chemical and physical water remediation technologies.

Neuro-Particle Swarm Optimization Based In-Situ Prediction Model for Heavy Metals Concentration in Groundwater and Surface Water

Limited monitoring activities to assess data on heavy metal (HM) concentration contribute to worldwide concern for the environmental quality and the degree of toxicants in areas where there are elevated metals concentrations. Hence, this study used in-situ physicochemical parameters to the limited data on HM concentration in SW and GW. The site of the study was Marinduque Island Province in the Philippines, which experienced two mining disasters. Prediction model results showed that the SW models during the dry and wet seasons recorded a mean squared error (MSE) ranging from 6 × 10⁻⁷ to 0.070276. The GW models recorded a range from 5 × 10⁻⁸ to 0.045373, all of which were approaching the ideal MSE value of 0. Kling–Gupta efficiency values of developed models were all greater than 0.95. The developed neural network-particle swarm optimization (NN-PSO) models for SW and GW were compared to linear and support vector machine (SVM) models and previously published deterministic and artificial intelligence (AI) models. The findings indicated that the developed NN-PSO models are superior to the developed linear and SVM models, up to 1.60 and 1.40 times greater than the best model observed created by linear and SVM models for SW and GW, respectively. The developed models were also on par with previously published deterministic and AI-based models considering their prediction capability. Sensitivity analysis using Olden’s connection weights approach showed that pH influenced the concentration of HM significantly. Established on the research findings, it can be stated that the NN-PSO is an effective and practical approach in the prediction of HM concentration in water resources that contributes a solution to the limited HM concentration monitored data.

History, Socioeconomic Problems and Environmental Impacts of Gold Mining in the Andean Region of Ecuador

Mining in Ecuadorian territory comprises three stages of Ecuadorian history: pre-Columbian, colonial, and republican times. In its beginnings, this activity did not have regulations or a legal foundation. The first Mining Law dates back to 1830, and it has been modified until the most recent update in 2009. The Andean region consists of 10 provinces, 9 of which have registered gold concessions, the most important of which are Loja, Azuay, and in recent years, Imbabura and Pichincha, which are the provinces with the highest number of reported concessions. The objective of this study focused on analyzing the historical and current situation of Artisanal and Small-scale Mining (ASGM) and the emergence of large-scale (industrial) mining. For the elaboration of this study, different methodological techniques were used, such as literature review, field interviews, and expert judgment validation. The main findings show that the provinces of Loja, Azuay, Imbabura, and Pichincha are the most conflictive areas in the region due to the impacts caused by mining activities. In socio-economic terms, there are conflicts between inhabitants in favor and against these activities and problems associated with human health. In environmental terms, the findings suggest historical contamination of water sources by heavy metals, which has altered the surrounding aquatic and terrestrial systems. Finally, the study concludes that implementing public policies should be promoted to balance socio-economic and environmental aspects in gold mining activities in the Andean region of Ecuador, strengthening the use of new technologies and education to raise awareness of the serious effects of mining activities.

Impact of metallurgy tailings in a major European fluvial-estuarine system: Trajectories and resilience over seven decades

Tailings containing mining and ore treatment waste, accumulated over long time periods are major contaminant sources at the watershed scale and may seriously impair environmental quality of river-sea continuums. A critical review of existing work in different disciplines addressing the multi-metal contamination of the Gironde Watershed, a major fluvial-estuarine model system representative of many other systems worldwide, has provided a condensed, yet pertinent overview on various aspects of this environmental problem. Combining long-term observation and contamination records from different environmental archives, there is a clear trend towards resilience for the main historical contaminants (Cd, Zn, Pb and Cu), yet suggesting that resilience needs appropriate management of both, tailings as the initial source and contaminated sediments acting as temporary metal traps which may transform into delayed sources. Contaminated sediment management is an increasingly important challenge due to (i) successful remediation at the contamination source itself (ii) global-change induced factors and strategies and (iii) lacking coordination of actions between upstream and downstream parts of the fluvial-estuarine continuum. Less studied and emerging metallic contaminants show recent trends in sediments and biota that are decoupled from the legacy contaminant trajectories due to recent sources and applications, suggesting that further work is needed to assess their potential impact on the environmental quality of the Gironde fluvial-estuarine system and that of other systems, especially in a context of worldwide rapidly growing mining activity and metal use.

Bottom-up cascading effects of quarry revegetation deplete bird-mediated seed dispersal services

Quarrying activities cause profound modifications on ecosystems, such as removal of vegetation cover, biodiversity loss and depletion of ecosystem services. Ecological restoration stands as a solution to revert such effects. Concomitantly, awareness is currently being given on ecosystem services and ecological processes to evaluate restoration efficiency. The objective of the study was to assess restoration success in a quarry subjected to restoration practices for the last 40 years involving the plantation of native Mediterranean vegetation and the non-native Aleppo pine Pinus halepensis. The study was carried out by assessing the effectiveness of seed dispersal service provided by birds in the restored quarry by comparing this service to neighbouring natural (shrubland) and other semi-natural areas (oak-pine mixed open and Aleppo pine forest) present at the landscape. For this purpose, we explored bird composition structure and seed dispersal networks using point counts and faecal samples of mist-netted birds. We also collected vegetation structure data and explored its effect on bird community composition. Our results showed that bird abundance in the restored quarry was significantly lower, and its bird community was compositionally different than natural shrubland and semi-natural areas. For instance, seed-dispersing birds, woody and shrub/ground foragers and partially migrators were the most affected groups at the restored area. Bird community composition and their traits were likely driven by vegetation characteristics, with higher native vegetation cover and fruit richness promoting higher bird abundance and Aleppo pine cover negatively influencing seed-dispersing birds. Concurrently, seed dispersal network in the restored quarry was less complex than in other areas. Seed dispersal services in the restored quarry were below the reported values for neighbouring natural and semi-natural areas and are likely driven by the low abundance of seed-dispersing birds. We consider that the causes affecting this group's low abundance can be related to revegetation measures favouring Aleppo pine, combined with a shallow soil depth and poor soil quality, which may have constrained native vegetation development. We conclude that seed dispersal services at the quarry are depleted, which may suggest a low restoration success concerning ecosystem functioning. Our results strengthen that quarry revegetation with non-native species must be avoided, since it alters bird community composition, and consequently, affects seed dispersal service provided by birds.

Radionuclides and Radiation Exposure in Tantalite Mining, Ethiopia

Tantalite and columbite ores have been reported as containing associated primordial radionuclides, such as uranium and thorium. Ethiopia is one of the world suppliers of tantalite ore through exploitation of Kenticha mine and tantalite production by a large number of artisanal miners. For the purpose of implementing the international standards for radiation protection of workers and members of the public, a preliminary assessment of radionuclides and radiation doses associated to tantalite mining was performed. Results confirmed and quantified the co-occurrence of uranium and thorium and their progeny in tantalite ore. Radiation doses at some workplaces may exceed the effective dose limit recommended by the international radiation safety standards for nonradiation workers and members of the public. Investments to be made in order to expand and modernize tantalite production in Ethiopia shall take into account the radiation hazards and implement a radiation protection program to prevent enhanced occupational radiation exposures and protect the public and the environment.

Synergistic effect of pistachio shell powder and nano-zerovalent copper for chromium remediation from aqueous solution

Pistachio shell powder supported nano-zerovalent copper (ZVC@PS) material prepared by borohydride reduction was characterized using SEM, FTIR, XRD, TGA/DTA, BET, and XPS. SEM, XRD, and XPS revealed the nano-zerovalent copper to consist of a core-shell structure with CuO shell and Cu(0) core with a particle size of 40-100 nm and spherical morphology aggregated on PS biomass. ZVC@PS was found to contain 39% (w/w %) Cu onto the pistachio shell biomass. Batch sorption of Cr(VI) from the aqueous using ZVC@PS was studied and was optimized for dose (0.1-0.5 g/L), initial Cr(VI) concentration(1-20 mg/L), and pH (2-12). Optimized conditions were 0.1 g/L doses of sorbent and pH=3 for Cr(VI) adsorption. Langmuir and Freundlich adsorption isotherm models fitted well to the adsorption behavior of ZVC@PS for Cr(VI) with a pseudo-second-order kinetic behavior. ZVC@PS (0.1g/L) exhibits q_max for Cr(VI) removal up to 110.9 mg/g. XPS and other spectroscopic evidence suggest the adsorption of Cr(VI) by pistachio shell powder, coupled with reductive conversion of Cr(VI) to Cr(III) by ZVC particles to produce a synergistic effect for the efficient remediation of Cr(VI) from aqueous medium.

"It Is Like We Are Living in a Different World": Health Inequity in Communities Surrounding Industrial Mining Sites in Burkina Faso, Mozambique, and Tanzania

Background: Health equity features prominently in the 2030 Agenda for Sustainable Development, yet there are wide disparities in health between and within countries. In settings of natural resource extraction (e.g., industrial mines), the health of surrounding communities is affected through myriad changes in the physical, social, and economic environment. How changes triggered by such projects translate into health inequities is poorly understood. Methods: This qualitative study explores potential layers of inequities by systematically coding perceived inequities of affected communities. Drawing on the framework method, we thematically analyzed data from 83 focus group discussions, which enrolled 791 participants from 10 study sites in Burkina Faso, Mozambique, and Tanzania. Results: Participants perceived inequities related to their individual characteristics, intermediate factors acting on the community level, and structural conditions. Due to environmental pollution and land loss, participants were concerned about unsecured livelihoods. Positive impacts, such as job opportunities at the mine, remained scarce for local communities and were claimed not to be equally distributed among community members. Conclusion: Extractive industries bear considerable risks to widen existing health gaps. In order to create equal opportunities among affected populations, the wider determinants of health must be considered more explicitly in the licensing process of resource extraction projects.

Unbridled coal extraction and concerns for livelihood: evidences from Odisha, India

Coal mining and its unfavourable consequences have generated global attention. It has further stimulated the paradoxical debate of development and desolation in the contemporary scenario. Since the coal resources are profusely available in India and it is comparatively less expensive, the country has been largely relying on it for its essential and non-essential consumption needs. Coal resources indirectly fulfil many of the modern requirements and comforts. Consequently, mining of minerals in general and coal in particular has become the prime focus. It helps to generate revenue, augment industrialisation and promote employment opportunities in India. Despite these progressive features, the opencast coal mining activities impose serious threats to the livelihood of the local communities. Based on critical review of the relevant literature, the article seeks to exhibit the mineral reserves and coal mining activities at global, national and regional context. The paper has incorporated a special focus on Odisha—a resource-rich state located in eastern part of India. Particularly, the two existing major coalfields—Talcher and Ib valley, situated in western part of the state—have been emphasised. The manifold adverse externalities of the coal mining practices on the livelihood pattern among the affected people have been assessed. Furthermore, the paper aims to examine the mining-induced threats on different livelihood capitals which has given rise to multiple risks and challenges.

Environmental sustainability disclosures in annual reports of mining companies listed on the Australian Stock Exchange (ASX)

Mining companies use environmental sustainability reporting to inform their stakeholders about their position in relation to environmental sustainability. This paper explores how these companies include topics related to the environment and its protection in their annual reports. The 100 largest mining companies listed on the Australian Stock Exchange (ASX) were included in the research sample, using market capitalisation as the size indicator. The investigation was performed by means of quantitative and qualitative content analysis of annual reports to identify relevant keyword occurrences. Results revealed that topics related to protection of the environment, emissions, carbon footprint, and climate change are addressed in companies’ annual reports. In line with research in other industries, this study confirmed that the intensity of communication about these topics varies with company size. A new methodology was developed to assess the extent to which mining companies inform the stakeholders about their environmental protection initiatives and to address the limited applicability of the GRI G3 disclosure checklist for sustainability reporting, thereby enhancing the theory of social licence to operate.

Effect of growth conditions on cell wall composition and cadmium adsorption in Chlorella vulgaris: A new approach to biosorption research

Biosorption of toxic metals in microalgae is a process relying on the presence of cell wall reactive groups acting as binding sites. This work studied the effect of culture conditions on the outer cell wall composition of C. vulgaris and cadmium biosorption. The experiments were conducted in continuous culture under light and nitrogen limitation at two growth rates (0.4 and 0.2 d^-1). Functional groups were profiled using ATR-FTIR spectrometry, and total cadmium biosorption was assayed. Significant differences in composition were attested the most salient being the absence of carboxyl groups in the light deprived states and a larger number of carbohydrates and amino groups in the nitrogen deprived cultures, particularly amino groups from deacetylated D-glucosamine polysaccharides. Higher biosorption was obtained with the nitrogen-restricted biomass, reaching a maximum of 11.9 mg_Cd/g_biomass, as compared to a minimum of 8.0 mg_Cd/g_biomass achieved in the light-restricted states. The increased biosorption exhibited by nitrogen-restricted strains was attributed to the deacetylated amino groups that have enhanced cation affinity. This work has shown that the characteristics of the outer cell wall can be engineered by culture conditions to improve biosorption, providing a new approach that opens up new research frontiers for the biosorption of hazardous metals.

Health impacts of industrial mining on surrounding communities: Local perspectives from three sub-Saharan African countries

Industrial mining projects can play an important role in global sustainable development if associated health risks are minimised and opportunities maximised. While a broad body of evidence from quantitative studies exists that establishes the interlinkages between mining operations and effects on public health, little research has been conducted investigating health impacts from the perspective of affected communities. This is particularly true in sub-Saharan Africa, where about a third of the remaining global mineral resources are endowed and health-related indicators for sustainable development are lagging behind. In this multi-country qualitative study, we explore community perceptions regarding impacts of industrial mining on their health and well-being. In nine study sites in Burkina Faso, Mozambique and Tanzania, we conducted 83 participatory focus group discussions with a total of 791 participants (385 men, 406 women). Our findings reveal a broad range of perceived impacts on environmental, economic and social determinants of health, with secondary health implications related to morbidity, mortality and well-being. Overall, perceived negative impacts prevailed, mainly related to environmental pollution, change in livelihoods or social disruption. Perceived positive impacts on health and well-being were related to interventions implemented by the mines such as new or improved water sources, health care facilities, roads and schools. The consistency of these findings across countries and study sites suggests a structural problem and indicates a pressing need to address health by acting on the wider determinants of health in mining regions. Participatory health impact assessment should be strengthened in host countries to foster strategic interventions, include marginalised population groups, and protect and promote the health of local communities. By including community perspectives on health before and during project implementation, policymakers can take advantage of economic opportunities while avoiding the pitfalls, bringing their communities closer to achieving good health and well-being goals by 2030 and beyond.

Identifying industry practice, barriers, and opportunities for mine rehabilitation completion criteria in western Australia

Around the world, the development of acceptable and achievable completion criteria is a necessary part of mine closure planning and fundamental to the successful transition of mined land to a post-mining use. Without adequate completion criteria, a mining company cannot proceed to the process of relinquishment, which is the ultimate goal of most mine closure processes. Despite the central role of completion criteria, there is still a need to build capacity and understanding of how to set targets and develop measurable completion criteria that are accepted by all stakeholders involved. We investigate how completion criteria are currently developed in one of Australia's major mining jurisdictions: Western Australia. Through an industry consultation process that involved interviews and a survey with a total of 102 participants from mining companies, consulting businesses, and relevant regulators, we highlight key challenges and opportunities that the sector faces to successfully define clear, achievable, and agreed completion criteria. This is one of the few industry-wide investigations to capture and analyze the perspectives of stakeholders involved in writing and assessing mine closure completion criteria. Results show that some major challenges included inconsistent coordination within and between stakeholder groups, a lack of knowledge or data about restoration, and an overreliance on status quo practices and post-mining land uses. Our work shows that ongoing research on ecological restoration and technological innovations is necessary, but that additional organizational and regulatory barriers need to be addressed to achieve a consistent, coordinated, multi-stakeholder approach to define completion criteria and to advance successful mine rehabilitation and relinquishment.

Establishing effective mine closure criteria for river diversion channels

Rivers are frequently relocated into new artificial channels because of mining activity. Current mine closure criteria do not adequately address river diversion practices causing an absence of guidelines and management of river diversion channels post-mining. During mine operation, river diversion channels are designed to convey large floods with an emphasis on channel stability and effective flow conveyance. After mine closure, it is now important for river diversion channels to behave more like a natural river system and imitate the characteristics of surrounding watercourses. Developing adequate closure criteria for river diversion channels is both a geomorphic and river restoration challenge. River diversion channels frequently perform poorly by creating problems during mine operation and can cause subsequent long-term legacy issues. This paper identifies the geomorphic and environmental issues of defining and implementing mine closure criteria for river diversion channels and suggests ways to improve current practices. Significant difficulties include the competing objectives of short-term channel stability and the long-term inclusion of environmentally favourable natural features, the difficulties of adequate hydrological prediction, limited understanding of regionally appropriate river characteristics and competing objectives from varied stakeholders. Effective river diversion closure criteria should include extensive hydrological, geomorphic, and ecological planning with long-term guidelines established early in the mine planning process. Lastly, river diversion closure criteria should undergo continuous revision as our understanding of river restoration develops.

Intergenerational Externalities Influence for Exploitation Process of Rare Metal Minerals

Rare metal minerals are important strategic resources. Promoting the sustainable development of their mining process is not only related to energy and environmental issues, but also directly affects the sustainable development of the entire supply chain. Considering the influence of intergenerational externalities on the equilibrium in the rare metal mineral exploitation process is of critical significance to maintaining the sustainable development of rare metal minerals and securing a sustainable resource exploitation process. This paper develops a sustainability analysis model based on an intergenerational externalities influence and examines the influence of the shift in comprehensive production cost burden through the whole supply chain, which aims at the sustainable development of the exploitation process of rare metal minerals. The results indicate that in a vertically linked industrial chain, the upstream and downstream structure of the supply chain and the type of production cost are the factors that determine sustainable development. Upstream suppliers or countries should design their production systems based on their own circumstances. Specifically, when an upstream country has a low technological level for mineral exploitation processes and high development costs, a resource tax would be more effective in mediating sustainable development.

Tolerance of tomato to cadmium-induced stress: analyzing cultivars with different fruit colors

The objective of the present study was to assess the response of tomato cultivars with different fruit colors to exposure to increasing Cd levels in the substrate by measuring the impacts of Cd on the oxidative stress indicators and physicochemical features of fruits, as well as plant development and yield components. A completely randomized experiment in a 3 × 3 factorial design [tomato cultivar (which produces purple, red, or white fruits) vs Cd level in the substrate (0, 3.6, or 12 mg kg^-1)] was performed. The cultivation of plants in substrate containing 3.6 mg kg^-1 Cd did not affect yield, but fruits exhibited nonpermissive Cd concentrations in both peel and mesocarp across all cultivars. By contrast, yield was decreased in plants with red and white fruits after their cultivation in substrate containing 12 mg kg^-1 Cd, while the productivity of plants with purple fruits was maintained under such conditions. The hydrogen peroxide content in the fruit mesocarp depended only on cultivar. However, an increased lipid peroxidation level was detected in the mesocarp of purple fruits at the highest Cd concentration. No parameters of fruit quality [i.e., diameter, length, °Brix, pH, titratable acidity, color (L*, a*, and b*), and concentrations of lycopene and β-carotene in mesocarp] were affected by long-term exposure to Cd at 12 mg kg^-1. In conclusion, the results of this study suggested that the potential Cd side effects on diverse tomato quality features can be buffered at the fruit level because these features were maintained at the usual values despite high Cd concentrations in tomato peel and pulp. Moreover, these buffering mechanisms are independent of lycopene and β-carotene concentrations in fruit peel, since the three tomato cultivars that were evaluated in the present study (white fruits, possessing no or negligible concentrations of these carotenoids, and red and purple tomato, possessing high lycopene and β-carotene concentrations) were able to sustain several fruit quality parameters after long-term exposure to high Cd concentrations in the substrate.

Radiological Scouting, Monitoring and Inspection Using Drones

Human populations and natural ecosystems are bound to be exposed to ionizing radiation from the deposition of artificial radionuclides resulting from nuclear accidents, nuclear devices or radiological dispersive devices (“dirty bombs”). On the other hand, Naturally Occurring Radioactive Material industries such as phosphate production or uranium mining, contribute to the on site storage of residuals with enhanced concentrations of natural radionuclides. Therefore, in the context of the European agreements concerning nuclear energy, namely the European Atomic Energy Community Treaty, monitoring is an essential feature of the environmental radiological surveillance. In this work, we obtain 3D maps from outdoor scenarios, and complete such maps with measured radiation levels and with its radionuclide signature. In such scenarios, we face challenges such as unknown and rough terrain, limited number of sampled locations and the need for different sensors and therefore different tasks. We propose a radiological solution for scouting, monitoring and inspecting an area of interest, using a fleet of drones and a controlling ground station. First, we scout an area with a Light Detection and Ranging sensor onboard a drone to accurately 3D-map the area. Then, we monitor that area with a Geiger–Müller Counter at a low-vertical distance from the ground to produce a radiological (heat)map that is overlaid on the 3D map of the scenario. Next, we identify the hotspots of radiation, and inspect them in detail using a drone by landing on them, to reveal its radionuclide signature using a Cadmium–Zinc–Telluride detector. We present the algorithms used to implement such tasks both at the ground station and on the drones. The three mission phases were validated using actual experiments in three different outdoor scenarios. We conclude that drones can not only perform the mission efficiently, but in general they are faster and as reliable as personnel on the ground.

Potential of Eucalyptus globulus for the phytoremediation of metals in a Moroccan iron mine soil-a case study

The contamination left by abandoned mines demands sustainable mitigation measures. Hence, the aim of this study was to examine the phytoremediator ability of Eucalyptus globulus Labill. to be used for cleaning up metal-contaminated soils from an African abandoned iron (Fe) mine (Ait Ammar, Oued Zem, Morocco). Plantlets of this species were exposed to a control (CTL), a reference (REF), and a mine-contaminated soil (CS). Morphological (growth, leaf area) and physiological stress biomarkers (photosynthetic efficiency, pigments content, leaf relative water, and malondialdehyde (MDA) levels) and metal bioaccumulation were assessed. The growth and leaf area of E. globulus increased overtime in all soils, although at a lower rate in the CS. Its photosynthetic efficiency was not markedly impaired, as well as MDA levels decreased throughout the experiment in CS. In this soil, higher metal contents were detected in E. globulus roots than in leaves, especially Fe (roots: 15.98-213.99 μg g^-1; leaves: 5.97-15.98 μg g^-1) and Zn (roots: 1.64-1.99 μg g^-1; leaves: 0.67-1.19 μg g^-1), indicating their reduced translocation. Additionally, though at low extent, the plants bioaccumulated some metals (Pb > Zn > Cu) from CS. Overall, E. globulus may be potentially used for the phytoremediation of metals in metal-contaminated soils.

Health risk assessment of radioactive footprints of the urban soils in the residents of Dera Ghazi Khan, Pakistan

The aim of the study was to evaluate the radiation levels, radiological doses and excess lifetime cancer risk possessed by the urban soils that were collected from the vicinity of the exclusive mining and excavation centers of Dera Ghazi Khan. The high purity germanium detector was utilized for assessment of naturally occurring radionuclides (NORMs) in soil and results showed that the average activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K (37 Bq/kg, 43.07 Bq/kg, 737 Bq/kg respectively) surpassed the world's average documented values (35 Bq/kg, 30 Bq/kg, and 400 Bq/kg respectively). Moreover, the average values of radiological hazards assessment like radium equivalent, internal and external hazard indices, absorbed dose rate, annual gonadal dose equivalent and excess lifetime cancer risk were 155.70 (Bq/kg), 0.4, 0.5, 73.96 (nGy/h) 90.73 (μSv/y), 476.24 (μSv/y) and 0.31(10^-3) respectively. The data acquired was analyzed using descriptive statistics, cluster analysis and principal component analysis. ArcGIS (10.5) software was utilized for developing maps of radionuclide's concentration for the study area. Results of the study may serve as an important baseline radiometric data for future epidemiological studies and monitoring initiatives in the study area.