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Tailings dam failures cause catastrophic impact on the environment and surrounding communities. Incidences of failure in the recent past have caused industrialists and researchers to seek innovative ways for proactively managing their safety and disaster mitigation. Given Industry 4.0 technologies now available, researchers are looking to develop digital tools for cost-effective, realtime monitoring of tailings dams. However, published literature indicates that a reliable framework is still lacking. This paper proposes a framework for developing a data-driven system for monitoring tailings dam stability and early warning detection. The framework relies upon digital twin simulation and machine-learning (ML) techniques, and comprises four main components: realtime data collection, digital twin modelling, ML-based early detection and prediction, and intelligence-driven decision-support. Sensors gather real-time geophysical data from monitored structure, and the digital twin uses this data to simulate dam behaviour. ML algorithms analyse the data and simulations to enable early detection of instability and failure prediction. Literature suggests that digital twin and ML-based approaches may have advantages over traditional monitoring techniques and other AI-based methods. The paper concludes with a discussion of the framework's limitations, opportunities for improvement, and potential for application in mining and geotechnical engineering. The paper serves as a basis for model development and future research. [ABSTRACT FROM AUTHOR]

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Mine tailings stored in the tailings storage facility (TSF) are normally loose and failure-prone for several reasons, such as liquefaction, erosion, overtopping, piping, and high excess pore water pressure (PWP). The investigation of the mechanical behavior of tailings material is essential for engineering design and safety evaluation of the TSF during mining operations, closure, and rehabilitation. As such, laboratory compaction, consolidation, and direct shear strength experiments are carried out on three different fine-grained mine tailings, named coal tailings (CT), red mud (RM), and gold tailings (GT). Compared to CT and RM, GT showed higher dry density at the optimum moisture content (OMC) and lower compressibility. The permeability of GT is similar to RM but much higher than that of CT. CT and GT showed the highest cohesion and angle of internal friction, respectively, among the tested materials. The direct shear test, among all the methods used, provided the highest dry density and lowest void ratio. The final state parameters obtained in compaction, consolidation, and direct shear tests are critically compared, which is the novelty of this study. This research explored useful information on the geotechnical properties of different tailings that can help mining operators and researchers effectively design and manage the tailings in the TSF. [ABSTRACT FROM AUTHOR]

For more than 100 years upstreaming has been the dominant raising method for tailings storage facilities in Southern Africa. However, there is a growing view worldwide that upstreaming is inherently less safe than centreline or downstream raising of tailings storage facilities. Considering that more than 90% of the 250 plus operational tailings storing facilities in Southern Africa are upstream raised and cannot economically be converted to, or replaced by, downstream raised facilities, the arguments for and against upstreaming were examined in this study. It was found that no compelling reason exists to ban upstreaming in Southern Africa, provided that failure mechanisms are thoroughly considered to prevent serious design omissions. The ALARP (as low as reasonably practicable) approach is introduced as a practical method to deal with the risk of failure, and its hierarchical application is illustrated. [ABSTRACT FROM AUTHOR]

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Copyright of Cuadernos de Geografia: Revista Colombiana de Geografía is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tecnologia em Metalurgia, Materiais e Mineração is the property of Associacao Brasileira de Metalurgia e Materiais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article provides an outlook on the darker side of people's home experiences, as described by the inhabitants of Merafong, a township located on the Far West Rand, South Africa, where goldmining companies have had an immense impact on the region for more than a century. The mining industry has extended its influence everywhere, framing and re-forming the area, and in so doing, the perceptions of home and homeliness have changed radically. When the people of the Far West Rand describe the meaningful features of their home region they do not hesitate to talk about its negative side. They speak of illegal immigrants, drugs, criminality, arson, kidnapping, and sexual violence. They talk about dangers that lurk in the natural environment, such as sinkholes and the pollution of water and soil. Furthermore, they talk of the problems inherent in the political system, of illiteracy, corruption, inefficiency, and the long shadow of colonialism. They also speak at length about their experience of danger and fear. The Far West Rand, exemplified by Merafong, is by no means pictured as being perfect. In many aspects it is unpleasant, ugly, and even dangerous. But nevertheless, it is home. The data presented here was collected in the period 17-20 November 2015. The method followed and discussions held are examined below. These were followed by two written assignments. The six data collection sessions were attended by a total of 31 participants. [ABSTRACT FROM AUTHOR]

The objective of this study is to evaluate the concentrations of heavy metals and radionuclides in water and fish samples collected from six designated sampling stations along the Linshui River, in close proximity to a Uranium Tailing Pond situated in China. Additionally, it seeks to estimate the bioaccumulation of heavy metals and conduct risk assessments, both carcinogenic and non-carcinogenic, for consumers. Water and fish samples (yellowhead catfish and common carp) were systematically collected from six stations along the river from January to June 2023, adhering to ethical standards and standard protocols for assessing water quality. Samples underwent chemical preparation and analysis for heavy metals using Graphite Furnace Atomic Absorption Spectrophotometry and Cold Vapor Atomic Absorption Spectroscopy, and for radionuclides using gamma spectrometry, with all methods validated for accuracy. The water samples showed metal and radionuclide concentrations within acceptable limits, except for higher levels of U and Th compared to background values. Heavy metal concentrations were higher in common carp compared to yellowhead catfish, with both species exhibiting a similar trend. While non-carcinogenic health risk, as indicated by target hazard quotients, was low for consumers, the health risk data emphasized the carcinogenic threats posed by U238 and Th234. The study highlights the importance of implementing comprehensive river restoration measures. Additionally, the bioconcentration factor values indicate minimal accumulation of heavy metals in the muscle tissue of fish. • The concentrations of heavy metals in the Linshui River do not pose a risk to adult human health. • U and Th concentrations were higher than background values in Jiangxi province. • Common carp had higher heavy metal concentrations than yellowhead catfish. • U238 and Th234 pose carcinogenic threats to consumers of fish. • Bioconcentration factors suggested heavy metals did not accumulate significantly in fish muscle tissue. [ABSTRACT FROM AUTHOR]

• First accounting of CO 2 mineralization and utilization potential of tailings sand at the ownership scale in China. • Innovative ARIMA-cloud model predicted tailings sand production and consumption. • Analyzed carbon sinks under scenarios of technological leapfrog and elevated utilization. • Screened potential spatial clusters of mineralized carbon sinks from tailings sand. • The feasibility of mineralization project layouts was judged by enterprise size. The use of tailings sand for CO 2 mineralization and utilization (CMU) has been emerging globally, offering a sustainable solution for repurposing tailings sand while establishing a stable carbon sink. Despite several reports that evaluated process performance and project benefits, existing research has not delved into the project layout focusing on the tailings pond facility and the feasibility considerations from a cluster and ownership perspective. Conducting facility-scale refined mineralized carbon sink (MCS) and layout feasibility assessment is a key issue that needs to be addressed urgently. Here, we accounted for CMU potential (CMUP) of tailings sand using a sample of 6219 tailings pond ownerships in China, predicted future annual carbon sinks through an innovative ARIMA-cloud model, and analyzed the feasibility of project layouts within potential clusters concerning enterprise size. Our results indicate that the CMUP of accumulated tailings sand in China amounts to 1817.87 Mt. In a combined scenario involving future technological leapfrogging and increased utilization, the average annual carbon sink by 2030 is projected to be 24.73 Mt. A considerable reduction in project layout feasibility across all scenarios was observed due to the mismatch between carbon clusters and enterprise size. Our study reveals that CMU using tailings sand should be regarded as one of the essential green technologies in the portfolio of strategic Chinese CO 2 mitigation. However, we highlight the necessity of aligning cluster programs with the support capacity of the ownership enterprise to ensure the optimal project success. [Display omitted] [ABSTRACT FROM AUTHOR]

The Fundão Dam rupture in Mariana, Brazil spilled contaminated tailings across the Doce River basin reaching several towns such as Ipaba. Ibapa's agricultural and fishing activities declined by 50% due to the toxicity of sodium and ether-amine, followed by a reduction of nitrate resulting in inhibition of plant growth and biota. A settler's community in Ipaba composed of 51 families whose main sources of income were agriculture and fishing activities have abandoned their properties because the land became unproductive after the Fundão dam rupture, and the rural exodus is a current concern in the town. However, previous research has demonstrated that the remediation of sodium and ether-amine, as well as the recovery of soil fertility is feasible, enabling the establishment of the native Atlantic Forest and crop species. Such procedures are recommended to recover the agricultural production in Ipaba. Aiming at protecting these cropping areas against flooding, we propose the creation of riparian forests in the floodplains. In order to make the settlers able to properly manage their lands in a post-disaster scenario, a recovery plan for Ipaba may be implemented via nature based solutions supported by social capital actions such as agroforestry technical training schools and social association, which are shown through schemes and three-dimensional modelling. [Display omitted] • Fundão Dam rupture spilled contaminated tailings in the Doce River. • Agricultural and fishing activities declined by 50% at Ipaba town. • A settler's community of Ipaba have been severely affected by the disaster. • Soil remediation may help recover the agricultural production at settler's land. • A post-disaster recovery plan for Ipaba via social capital actions is proposed. [ABSTRACT FROM AUTHOR]

This paper aims to draw attention to the intricacies of hybrid network governance in a challenging institutional landscape. The empirical focus is a case study of the recovery process from the Fundão dam rupture, Brazil's most significant environmental disaster, and the largest in the world involving tailings dams. To drill into the barriers to cross-sector partnerships, we adopted a multi-methods approach, including interviews, grey materials and documents, participant observation and social network analysis. We identified interrelated barriers and grouped them into institutional, power and knowledge barriers, which act through a positive feedback loop leading to a structural arrangement that is inadequate for collaboration in disaster management. As a result, the Doce river basin's recovery process has taken the form of a wicked industrial disaster, enabling a "chain reaction" of increasing wickedness. We thereby advance cross-sector partnership research by drawing attention to the underlying causes of failure and offer guidance to public and private managers on possible strategies to address the barriers to cross-sector partnerships. • Wicked industrial disasters are processual phenomena, not just an event with an impact. • Interrelated barriers create a positive feedback cycle hindering collaboration. • Cross-sector partnerships barriers are complex and create uncertainty and dispute. • Cross-sector partnership should have been formed based on moral and material concerns. [ABSTRACT FROM AUTHOR]

Trace metal contents and fluxes in downward particulate matter and dated sediment cores of the NW Alboran Sea are analysed in this study with the aim of assessing the role of the Atlantic inflow on their transport. Increases in Zn, Cu and Pb were detected in downward particulate matter collected by sediment traps after river flooding events and after the Aznalcollar mining spill. Their arrival coincided within the recently estimated time range for river particles discharged into the Gulf of Cádiz to reach the Alboran Sea, indicating that their transfer is enhanced during events of increased river inputs of contaminated particulate matter. This also suggests that the effects of potential tailing dam failures in the Gulf of Cádiz watersheds could reach the Alboran Sea. These trace metals also increased in the sediment cores from the continental rise since the second half of the 19th century, suggesting that contaminated particles have been continuously transferred towards the Mediterranean Sea since that time, when mining concessions and production increased in the SW Iberian Pyrite Belt. [Display omitted] • Contaminated sediment was transferred from the Gulf of Cádiz to the Alboran Sea. • The transfer of trace metal-enriched particles increased after major river flood events. • Trace metal enrichments were also detected after the Aznalcollar tailings dam failure. • Pyrite production and trace metals in Alboran Sea sediments have increased since the 1850s. • Potential tailing dam failures in the Gulf of Cádiz watersheds could affect the Alborán Sea. [ABSTRACT FROM AUTHOR]

Environmental impact assessment (EIA) is a policy tool used all around the world to predict, mitigate, and manage the impacts and risks of development proposals. This tool, if well implemented and articulated with licensing procedures, can result in improvements of project design and in the prevention and mitigation of environmental and social harms. But sometimes EIA can fail, as illustrated the collapse of the Brazilian tailings dams Fundão and B1, in 2015 and 2019 respectively. Despite having gone through licensing and EIA procedures, the two dams collapsed, killing almost 300 people. This study set out to understand how the vulnerability of downstream communities to dam breaks were predicted and managed in the dams' EIA processes. This study also tried to understand whether the EIA process of a newly approved tailings dam in Brazil (Maravilhas Dam III) improved the prediction of safety risks to downstream communities. The study was based on literature reviews and a content analysis of eighty-four (84) key documents related to the dams' licensing and EIA procedures. The study found that the risk-related studies of the dams were based on a variety of methods (e.g., Preliminary Hazard Analysis, Failure Mode and Effects Analysis, Dam Break simulations, Contingency Plans) that were implemented in different phases of the licensing procedures. It was possible to identify several flaws and limitations in these methods, such as vagueness, late implementation, fragmented reviews of interdependent risks, and low influence on decision-making. Both the Fundão and B1 dams were approved despite the lack of in-depth and up-to-date risk assessments. Public consultations were generally weak and plagued by tokenism. Post-approval procedures, while informed by monitoring, audits and inspections that confirmed problems in the dams, were unable to educate developers and State authorities about the likelihood of failures and the safety risks to communities. Overall, the Fundão and B1 cases show the importance of not only predicting but also managing risks in a timely, transparent and articulated manner. The Maravilhas III Dam, compared to Fundão and B1, was found to have sounder evaluations of safety risks and stronger public participation. The regulatory and voluntary frameworks concerning tailings dams have improved in recent years. The projects of Fundão and B1 could not receive an environmental license had they been subject to the current Brazilian legislation, because they proposed a now-banned technology (upstream dams) and had vulnerable communities located in self-rescue zones, which is now legally unacceptable. Despite these regulatory changes, there is still room to improve regulations, guidelines and Terms of References for risk analysis and its articulation with impact assessment and public participation. The article discusses the academic implications of the cases to international audiences and put forward several practical recommendations. • This study evaluated the integration of risk analysis and EIA. • The prediction and management of risks to downstream communities are explained. • The EIAs of two of the world's most catastrophic tailings dam failures were investigated. • Risks to downstream communities were repeatedly underestimated. • The study provides several entry points to improve risk analysis in the EIAs of dams. [ABSTRACT FROM AUTHOR]

Copyright of Tecnologia em Metalurgia, Materiais e Mineração is the property of Associacao Brasileira de Metalurgia e Materiais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tecnologia em Metalurgia, Materiais e Mineração is the property of Associacao Brasileira de Metalurgia e Materiais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Philippines is one of the mineral-rich countries in the world with an estimated US$840 billion worth of untapped mineral wealth, catapulting the mining industry as a significant economic player providing substantial contribution to the national revenue and generating employment opportunities for the Filipino people. However, the detrimental impact of mining to the country has also been heavily criticized as it causes massive potential destruction to environment and wildlife ecology such as acid mine drainage and contaminant leaching, soil erosion, and tailing impoundments among others. These conflicting interests are reflected in the mining discourses stoked or dimmed by media, which influence the readers' construal of meanings in the mining texts, social actors' roles in the mining industry, and the urderlying contexts of the mining reality. Drawing on critical discourse analysis, this study described the linguistic and discursive features of Philippine mining discourse in media texts. The study used 224 news articles published by three online portals within five years. Local news reports and peripheral discourses obtained through interviews with local "symbolic elites" in the identified mining communities and other archival documents supplemented the news texts. The UAM Corpus Tool, a software for linguistic tagging, complemented the manual analysis in identifying the social actor theme. Findings revealed that government actions, economic phenomenon, and political actors are the most prevalent themes in the mining news reports. Moreover, results showed that local news tends to focus more on the mining's environmental impact, whereas the national news tends to put more premium on the mining's economic impact. This means that the media allotted a much lesser spatio-temporal space for the environment and Indigenous Peoples' cause. The findings further invalidate the assumptions that mining discourse is primarily concerned with environmental related issues. [ABSTRACT FROM AUTHOR]

Mining is of great relevance to the global economy, but its activities are challenging due to socio-environmental impacts. In January 2019, an iron ore tailings dam collapsed in Brumadinho (Minas Gerais, Brazil) releasing 12 × 106 m3 of tailings, causing human losses and devastation around 3.13 × 106 m2 of a watershed. In this context, the present study aimed to investigate the potential toxic effects of tailings from the collapsed dam using earthworms Eisenia andrei as a model organism for terrestrial environments. An extensive set of tests was performed, including behavioral (avoidance), acute (mortality and biomass) and chronic tests, such as biomass, reproduction and cytotoxicity (viability and cell density and change in coelomocyte pattern). The physical-chemical characterization revealed a higher density of the tailings in relation to the control soil, which can result in physical changes, such as soil compaction and surface sealing. Aluminum, Ca, Fe, Hg, Mg, Mn, K, Na and P registered higher concentrations in the tailings compared to the control soil, while Total Nitrogen, Total Organic Carbon and Organic Matter were higher in the natural soil. Based on the avoidance test, an EC 50 of 27.18 ± 2.83% was estimated. No lethality was observed in the acute exposure, nor variations in biomass in the acute and chronic assays. However, there was a tendency to reduce the number of juveniles in relation to cocoons in the proportions of 3125; 12.5 and 25%. Significant changes in viability, cell density and pattern of amebocytes and eleocytes were observed up to the 35th day of exposure. A multi-biomarker approach (Integrated Biological Response version 2) indicated concentration-dependent effects and attenuation of cellular changes over time. These are the first results of chronic effects on earthworms exposed to tailings from the B1 dam. Despite being conclusive, we highlight the possible heterogeneity of the tailings and the necessary care in extrapolating the results. [Display omitted] • Lethality and biomass changes were not observed in acute exposure. • First assessment of chronic effects on earthworms exposed to the tailings. • Changes in viability, cell density and coelomocyte pattern were observed. • Chronic effects at the cellular level decreased over time. • A multi-biomarker approach indicated concentration-dependent effects. [ABSTRACT FROM AUTHOR]

In an upstream tailings dam, loose layers might occur at different depths due to melting of frozen layers deposited during freezing temperature in Sweden. Reduced shear strength of such layers in a tailings dam might cause stability problems. Due to slow consolidation process, it is unknown, whether self-weight of a high tailings dam could have influence on strength and stiffness of soft tailings located at different depths. For numerical modelling, appropriate strength and stiffness properties of soft tailings are needed. For this purpose, loose layers in an upstream tailings dam were identified based on results of cone penetration tests. Consolidated Drained (CD) triaxial tests were conducted on undisturbed soft tailings collected from different depths of the dam. The results indicated that depth did not have considerable influence on strength and stiffness of tailings. Hardening Soil Model (HSM), at high confining pressures and axial strains underestimated stiffness of soft tailings under CD triaxial state. This study shows that: (i) proper care is needed in evaluating strength and stiffness parameters for soft tailings, and (ii) use of the HSM is likely to predict more deformations which could give an early warning before an actual failure of a tailings dam. [ABSTRACT FROM AUTHOR]

Copyright of Tecnologia em Metalurgia, Materiais e Mineração is the property of Associacao Brasileira de Metalurgia e Materiais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In November 2015, a tailings dam ruptured and affected the second largest nesting site of loggerhead sea turtles in Brazil. This study aimed to evaluate the reproductive success, and trace elements in female's plasma, freshly laid eggs, unhatched eggs, and dead hatchlings of loggerhead turtles that nest in the coastal area exposed to the mining waste (Povoação, Espírito Santo state) and compare them with animals from an area that was not affected by the tailings (Praia do Forte, Bahia state). Plasma concentrations of As, Cd, Cr, Fe, and Zn were significantly higher in samples from Povoação in comparison to turtles from Praia do Forte. In Povoação, unhatched eggs and dead hatchlings had higher As, Cu, Hg, Mn, and Zn concentrations than freshly laid eggs, and trace elements correlated with the hatching and emergence success. Our findings suggest that the higher concentrations of some metals may influence the incubation period and reproductive success of loggerheads in the affected area. [Display omitted] • A dam collapsed in Brazil affecting a nesting site of loggerhead turtles (Povoação). • Loggerheads from Povoação had higher As, Cd, Cr, Fe, and Zn concentrations in the blood compared to animals from the unaffected area. • Unhatched eggs and dead hatchlings had higher concentrations of some metals than freshly laid eggs. • Metals in the sediment influenced egg concentrations during incubation period. • Correlations between metals and reproductive parameters were found in Povoação. [ABSTRACT FROM AUTHOR]

The main purpose of this study was to build multivariate classification models using water quality monitoring data for the hydrographic basin of the Gualaxo do Norte River, Minas Gerais state, Brazil, which was impacted in 2015 by the rupture of a containment structure for iron ore tailings. A total of 27 points were evaluated, covering areas affected and unaffected by the disaster, with monitoring of chemical, physical, and microbiological variables during the period from July 2016 to June 2017. Multivariate classification techniques were applied to the data, with the aim of developing models to determine when the impacted locations would present characteristics equivalent to those existing prior to the rupture. Classification models constructed using PLS-DA and LDA were able to predict three classes: unaffected main river, affected main river, and tributaries. The first technique was able to clearly differentiate the three classes for the data evaluated, achieving averages corresponding to 90% accuracy. The second method was consistent with the first, identifying the chloride content, conductivity, turbidity, and alkalinity as discriminatory variables, among those monitored, with the relationships among the parameters being coherent with the environmental conditions of the region. The model, with a correct classification rate of 91.67%, enabled identification of the behavior of new samples, using only these easily measured variables. In summary, application of the multivariate statistical tools allowed the development of models capable of providing information about the recovery process of an ecosystem impacted by the greatest environmental disaster to have occurred in Brazil. [Display omitted] • Assessment of the long-term environmental effects of the Fundão dam failure, Brazil. • Multivariate classification models to assess the profile impacted and non-impacted. • Samples collected in the dry season already showed pre-disaster characteristics. [ABSTRACT FROM AUTHOR]

Hardpans are massively indurated layers formed at the top layer of sulfidic tailings dams, which develop cementation structures and result in heavy metal immobilization. However, the micro-structural and complex forms of the cementing materials are not fully understood, as well as the mechanisms by which Zn and Pb are stabilized in the hardpans. The present study deployed synchrotron-based X-ray fluorescence microscopy (XFM) to have characterized the cementing structures, examined the distribution of Fe, Zn and Pb, and obtained laterally-resolved speciation of Zn within the hardpans using fluorescence X-ray absorption near-edge structure (XANES) imaging. The XFM analyses revealed that the Fe-rich cement layers consisted of Fe (oxyhydr)oxides coupled with amorphous Si materials, immobilizing Zn and Pb. Through laterally-resolved XANES imaging analyses, Zn-ferrihydrite-like precipitates were predicted to account for >76% of the total Zn within the Fe-rich cement layers. In contrast, outside of the cement layers, 9–63% of the Zn was estimated as labile ZnSO 4 . 7H 2 O, with the remainder in the form of Zn-sulfide. These findings demonstrated that the Fe-rich cement layers were critical in immobilizing Zn and Pb within hardpans via mineral passivation and encapsulation, as the basis for long-term geochemical stability in the hardpan layer of sulfidic mine tailings. Image 1 • Fe-rich cement layers were distributed heterogeneously across the hardpan profile. • Fe-rich cement layers consisted of Fe (oxyhydr)oxides coupled with amorphous Si materials, immobilizing Zn and Pb. • Zn was stabilized within the Fe-rich cement layers as a Zn-ferrihydrite-like precipitate. [ABSTRACT FROM AUTHOR]

In 2015, the Fundão tailing dam collapsed over the district of Bento Rodrigues (Mariana, Minas Gerais, Brazil) causing deaths, hundreds of homeless families and incalculable environmental degradation. Environmentally, economically and socially sustainable strategies are needed for the recovery of the affected areas. The main goal of this study was to evaluate the development, biomass production and toxic mineral elements absorption of three species of aromatic grasses (Chrysopogon zizanioides, Cymbopogon citratus and Cymbopogon winterianus). These three species were planted on polypropylene pots filled with the iron ore tailings collected from the topsoil of the Bento Rodrigues district. The pots were fertilized with increasing doses of organic compost associated with mycorrhizae as a phytomanagement strategy. A 4 × 2 factorial scheme was used. The seedlings were fertilized with four doses of organic compost, with or without mycorrhizae. At the highest dose of the organic compost (2 kg.plant−1), the total dry matter (dry matter of the aerial part + dry matter of the roots) for C. zizanioides was 4.5 times higher than the control (tailing only). For C. winterianus and C. Citratus was 3.8 and 2.8 times higher than the control, respectively. Inoculation with mycorrhizae improved biomass production, especially in C. zizanioides. The Fe and Mn levels found in the aerial part of the plants fertilized with organic compost were lower than those just growing on the iron ore tailings for the three species, which suggest that the organic matter apparently helped the plants in the exclusion of the hazardous substances and therefore increased the tolerance to these adverse environmental conditions. C. zizanioides , associated with organic matter and mycorrhizae, would be the recommended species. The proposed phytomanagement strategy can have a significant contribution to the gradual recovery of the affected area and also serve as a source of income for the local population. Image 1 • Organic compost and mycorrhizae promoted the vegetative growth. • Fe, Mn and Na levels are far above normal levels in soils. • Species absorbed of Fe and Mn metals were above the toxicity limits of plants. • Vetiver is the recommended species to phytomanagement in area. This study presents a social, environmental and economic strategy for the recovery of areas affected by the remediation of iron ore tailings from Fundão dam, Mariana, Brazil, using a phytomanagement strategy with aromatic grasses, fertilized with organic compost and associated with mycorrhizae. [ABSTRACT FROM AUTHOR]

The rupture of the Fundão mine dam in Mariana municipality, Minas Gerais State, Brazil, spilled the tailings across the Doce River basin. These tailings, composed of residues discarded from the beneficiation of iron ore, are rich in SiO2 and Al2O3, as well as some ether amine compounds and NaOH. The aim of this study was to assess the distribution of these sediments, as well as their effect on the riparian zones reached, as compared with preserved sites. Sediment deposition in the river resulted in a morphological change from a meandering profile to a braided aspect. The nutrient and mineral content (P, K, Ca, Mg, Cu, Fe, Mn, Zn, and NO3−) and soil organic matter of the sediments were depleted, whereas NH4+, Na, and pH increased. A random presence of ether amines in the sediments was confirmed by quantitative and chromatographic analyses, with concentrations ranging from 0 to 57.8 mg kg−1; Na reached values as high as 150 mg kg−1. The impact of the dam tailings on biota was assessed by estimating total microbial biomass (phospholipid fatty acids), which were depleted in sediments relative to soils from preserved sites. Overall plant mortality, as well as a low resilience capacity, were also observed. Ether amines and Na present in the sediments had a strong toxic effect in the environment. Identification of these substances as the main impact factors will help guide future remediation efforts. Core Ideas: Dam disruption caused changes in the fluvial profile and nutrient depletion in the sediment.Depletion of microbial biomass in the sediment and plant mortality occurred.Despite the low organic matter and NO3− in the sediment, NH4+, Na, and pH increased.The environmental impact was attributed to the increase in NH4+, pH, and Na.Ether amine and Na from the dam are the main toxic factors. [ABSTRACT FROM AUTHOR]

Abstract The combined application of plant, microorganism, and amendment on the phytoremediation of heavy metals was optimized as a remediation technique for mine tailings by a field-scale orthogonal (L 16) experiment, aimed to achieve the maximum of phytoremediation effect. Soybean, M. Circinelloides, and A3 amendment (organic fertilizer: rice husk: biochar: ceramsite = 1:1:2:1) were recommended as the best plant, microorganism, and amendment materials, respectively. With the combined plant, microorganism, amendment application, effective fractions of Cu, Zn, Pb, Cd, Mn were immobilized for decreased bioavailability, indicating the phytostabilization served as a major repair pathway. Plant length and biomass in the treatments were significantly higher than that in the control, indicating their phytoremediation potentials were enhanced. The final contents of heavy metals in soil were decreased, and the removal rates of soil heavy metals were in the order of Pb＞Cd＞Cu＞Zn＞Mn. Temporal variations of soil microorganism populations indicated that the abundance of soil microorganism in the treatments was significantly higher than that in the control, and bacteria became the dominant microbial species. Results showed that the soil organic matter and catalase, urease, phosphatase activities of the treatments were all significantly higher than that of the control. This study provided optimized combined plant, microorganism, amendment materials in the enhanced phytoremediation field to make up the deficiencies of the long-term phytoremediation for heavy metals. Highlights • The combined of plant, microorganism, amendment was an enhanced remediation way. • Phytostabilisation served as a major phytoremediation pathway for heavy metals. • Mucor circinelloides was one of the best microorganism options. • Soybean was one of the best plant options. • Biochar played the most important role in the phytoremediation effect of amendment. [ABSTRACT FROM AUTHOR]

We studied arid desert soils from Namibia (Rosh Pinah) that were contaminated with up to 7 mg kg −1 of thallium (Tl) via dust emitted from a local flotation tailing dam. Chemical extractions of waste and soil materials indicated that most of the Tl is strongly bound, in accordance with X-ray diffraction and X-ray absorption spectroscopy data that point to the predominant association of Tl with metal sulfides and phyllosilicates. The isotope fractionation factor ε 205 Tl of the soil samples (from −0.4 to +3.8) shows a positive linear relationship (R 2  = 0.62) with 1/Tl, indicative for the mixing of two major Tl pools, presumably anthropogenic Tl and geogenic Tl. The ε 205 Tl value for the topmost soil samples (∼+3) closely matches the ε 205 Tl value for post-flotation waste particles with a diameter of <0.05 mm, whereas the bulk flotation waste exhibits a significantly larger ε 205 Tl value (∼+6). These variations are in accordance with predominant atmospheric transfer of Tl from the tailings to the adjacent soils via fine (dust) particles. The identified minimal Tl alteration in soils indicates that only a small part of the Tl could be potentially released and passively enter the vegetation, local population and/or food chain in the long term. From this viewpoint, Tl does not represent such an important environmental concern as other (abundant) contaminants at the locality. Furthermore, there could be a relevance for other alkaline desert soils, including those where Tl pollution plays a major role. [ABSTRACT FROM AUTHOR]

The tailings reservoir is a major hazard source with high potential energy, which may cause artificial debris flow. The stability of the tailings reservoir is extremely important to the normal operation of the mining enterprises and the safety of people's lives and property. In order to reduce the risk of a tailings accident, a multivariate linear regression model, a BP neural network and a regression analysis model optimized by genetic algorithm are established in this article to discuss the monitoring and warning method of the tailings reservoir. It takes the safety monitoring data of the Huangmailing tailings as an example to make a comparison of three forecasting models by taking fitness, simulating capability of initial data and the predicting ability of new data into consideration. The results of the experiment show that the BP neural network forecasting model is better able to predict safety monitoring data over the other two models. The predicting ability of the regression analysis model optimized by genetic algorithm is better than the forecasting capability of the multivariate linear regression model. [ABSTRACT FROM AUTHOR]

The failure of the mining tailings dam in Mariana, Minas Gerais, Brazil, was the largest disaster of its type in Brazil, generating serious environmental and socioeconomic problems. The aim of this study was to identify potential sites for the disposal of the tailings that accumulated along the watercourses affected by the dam failure in the municipalities of Mariana and Barra Longa, as well as to quantify the area affected by the tailings. To quantify the area affected by the tailings dam failure, the Land Change Modeler (LCM) tool was used to verify the changes in land use and land cover that occurred in the periods before and after the environmental impact. For the identification of the suitable sites for tailings disposal, multicriteria analysis was performed using the Idrisi Selva ® software and considering three scenarios to identify potentially affected areas through the application of the weighted linear combination (WLC) and ordered weighted average (OWA) techniques. In scenario 1, the WLC technique was applied, considering average risk and high compensation. In scenarios 2 and 3, the OWA technique was applied, with high risk and high compensation for scenario 2 and low risk and high compensation for scenario 3. The highest suitability value for tailings disposal was identified in scenario 2, which obtained the maximum value of 213 on a scale of 0–255, while for the scenarios 1 and 3, the suitability values were 158 and 124, respectively. The largest site for the tailings dam identified in the analysis for the municipally of Mariana has a size of 0.25 km 2 and obtained a suitability value of 207. In the municipally of Barra Longa, the largest site identified has a size of 0.037 km 2 , with maximum suitability value of 209. In relation to the changes in land use and cover, it was verified that the vegetated areas, composed mainly of riparian forest and pasture, presented greater losses as a consequence of the dam failure, with reductions of 11.99 and 4.81 km 2 , respectively, demonstrating that the dam rupture disaster has caused serious damage to the environment and the population living in the region. [ABSTRACT FROM AUTHOR]

The mineralogical and geochemical parameters on soil, waste, and tailings are major components for water quality assessments because they dictate the behavior of the chemical composition and water–rock interactions. Arsenic and trace metal contamination occasionally occurs because of the oxidation of arsenic-rich minerals and hydrothermal alteration or because of anthropogenic influences, such as industrial mining activity. This study aimed to understand the characteristics of tailings, soils, surface water, and groundwater to evaluate the possible geochemical dispersion of metals employed in tailing storage facilities. A study site at the former epithermal Au–Ag mine in Central Kalimantan, Indonesia, was selected because it was suitable for investigating the geochemical behavior of trace metals in water and solid samples and their possible contribution to metal contamination in tropical regions. A detailed study of the tailings comparing mineralogical and geochemical analysis indicates that the presence of unaltered, intermediate, and oxidized zone within the tailings can be related to the sulfides alteration indices (SAI). These zones include an unoxidized zone in the submerged areas where sulfides, including pyrite with less sphalerite and galena, remain fresh. In the intermediate zone, pyrite starts to change to iron oxyhydroxide. The SAI parameters from the intermediate zone, extending 50 cm below the tailing surface, indicate that only a few grains of pyrite in this zone are weakly altered and are capped by a thin (<10 μm) iron oxyhydroxide. The oxidized zone is indicated by traces of remaining pyrite and iron oxyhydroxide as the primary mineral. Heavy metals and rare earth elements from tailings storage facilities were scavenged from the soil solutions by groundwater. The stable isotopes of oxygen, hydrogen, and dissolved rare earth elements (REEs) were used as natural tracers in systems affected by acid mine drainage. The results showed that stable isotope and rare earth elements data do not support contamination between the surface and groundwater. This study found that the oxidation of ferrous iron to ferric ion and precipitation of Fe-oxyhydroxides in soil and water has a close spatial relationship with rare earth elements, which are concentrated only in intermediate and oxide zones. • Characterization of mineralogy of solid and water chemistry of Au–Ag tailings. • Variation in tailings oxidation featured by sulfide alteration indices. • Shallow water cover may be adequate to limit oxidation and acid mine drainage. • Stable isotope and rare earth elements do not support environment contamination. • REEs concentrations are controlled by the existence of kaolinite, Mn-Fe oxide-bearing minerals. [ABSTRACT FROM AUTHOR]

This paper presents three-dimensional (3D) and two-dimensional (2D) axisymmetric finite element analyses of a corner of a tailings dam. The analyses were performed to: (i) locate tension and/or low-compression zones and evaluate slope stability during sequential raising of the dam corner, and (ii) find whether the results of 2D axisymmetric analyses could be reliable for the dam corner. The corner is a potentially weak section of the dam, where tension and/or low-compression zones may develop. Development of such zones inside the dam corner can lead to cracks and initiation of internal erosion. The results of both the 3D and 2D axisymmetric analyses indicated that (i) tension and/or lowcompression zones were located in vicinity of surface of the dam corner mainly above the phreatic level, and (ii) the dam corner was stable up to the planned height if it was gradually strengthened with rockfill berms on the downstream side. The results of 2D axisymmetric analyses showed a fairly good agreement with those of 3D analyses. It is concluded that 2D axisymmetric analyses are appropriate for this dam corner. This implies that significant computational time can be saved by utilizing 2D analyses instead of 3D analyses. [ABSTRACT FROM AUTHOR]

On 5 November 2015, the Fundão tailings dam collapsed and its content first reached River Doce and then the Atlantic Ocean by 22 November. This study focuses on the oceanic time and space patterns of river discharge dispersion. By using an ocean model together with nLw(555) and RGB images from MODIS sensors, the river plume was followed for 2 months after the arrival of the tailings at the ocean. The results show the huge effect of this accident and reveal that riverine waters may have dispersed hundreds of kilometres, reaching regions as far as the shelf in front of the city of Rio de Janeiro. The movement of the freshwater was essentially to the south in accordance with the seasonal wind regime. Episodic frontal systems, leading to wind reversion, and oceanic mesoscale features contribute to the offshore dispersion of the plume. The region more often in contact with the riverine waters was located at the inner shelf between the river mouth and the city of Vitória, turning to the outer shelf and shelf break at lower latitudes. [ABSTRACT FROM AUTHOR]

Large quantities of lead/zinc (Pb/Zn) mine tailings were deposited at tailings impoundments without proper management, which have posed considerable risks to the local ecosystem and residents in mining areas worldwide. Therefore, the geochemical behaviors of potentially toxic elements (PTEs) in tailings were in-depth investigated in this study by a coupled use of batch kinetic tests, statistical analysis and mineralogical characterization. The results indicated that among these studied PTEs, Cd concentration fluctuated within a wide range of 0.83-6.91 mg/kg, and showed the highest spatial heterogeneity. The mean Cd concentrations generally increased with depth. Cd were mainly partitioned in the exchangeable and carbonate fractions. The release potential of PTEs from tailings was ranged as: Cd > Mn > Zn > Pb > As, Cd > Pb > Zn > Mn > As and Cd > Pb > Mn > Zn > As, respectively, under the assumed environmental scenarios, i.e. acid rain, vegetation restoration, human gastrointestinal digestion. The results from mineralogical characterization indicated that quartz, sericite, calcite and pyrite were typical minerals, cumulatively accounting for over 80% of the tailings. Sulfides (arsenopyrite, galena, and sphalerite), carbonates (calcite, dolomite, cerussite and kutnahorite), oxides (limonite) were identified as the most relevant PTEs-bearing phases, which significantly contributed to PTEs release from tailings. A combined result of statistical, geochemical and mineralogical approaches would be provided valuable information for the alteration characteristics and contaminant release of Pb/Zn mine tailings. [Display omitted] • Cd showed highly heterogeneity, and migrated towards the deeper tailings layers. • The release kinetics of toxic elements were studied under three simulated scenarios. • Among these studied PTEs, Cd was the highly mobile element in Pb/Zn tailings. • The most key hosting phases were identified for PTEs release by MLA analysis. [ABSTRACT FROM AUTHOR]

This study investigated the collapse of B1 mine-tailings dam that occurred in 25 January 2019 and severely affected the Brumadinho region (Minas Gerais state, Brazil) socially, economically and environmentally. As regards water resources, the event impacted the Paraopeba River in the first 155.3 km counted from the dam site, meaning nearly half the main water course downstream of B1. In the impacted sector, high concentrations of tailings-related Al, Fe, Mn, P in river sediment-tailings mixtures and water were detected, as well as changes to the reflectance of riparian forests. In the river water, the metal concentrations raised significantly above safe levels. For caution, the water management authorities declared immediate suspension of Paraopeba River as drinking water source to the Metropolitan Region of Belo Horizonte (6 million people), irrespective of representing nearly 30% of all supply. In this study, the main purpose was to assess potential links between tailings distribution, river water composition and reflectance of forest vegetation, which worked out as latent variables in regression models. The latent variables were represented by numerous physical and chemical parameters, measured 4 times in 22 sites during the dry period of 2019. The modeling results suggested the release of aluminum and phosphorus from sand fractions in the mine tailings as major cause of water contamination. The NDVI changes were interpreted as environmental deterioration. Changes in redox potential may have raised manganese concentrations in surface water further affecting the forest NDVI. Distance from the B1 dam and dissolved calcium appear to attenuate deterioration. Overall, the regressions allowed robust prognoses of environmental deterioration in the Paraopeba River under low flow conditions. More importantly, they can be transposed to similar dam ruptures helping environmental authorities to decide upon measures that can bring the affected rivers to pre-rupture conditions. [Display omitted] • Rupture of B1 dam in Brumadinho released 2.8 Mm3 of tailings into the Paraopeba River. •Al, Mn and P were elements of tailings-related water contamination in the dry period. •Tailings represented 59.4% and agriculture 39.6% of observed water contamination. •Tailings-related water contamination correlated with riparian forest deterioration. •Deterioration decreased with the distance from B1 dam, being residual beyond 155.3 km. [ABSTRACT FROM AUTHOR]