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de Souza JPR, Garnier J, Quintarelli JM, de Sousa Tonhá M, Roig HL, Seyler P, de Souza JR. Adapted Sequential Extraction Protocol to Study Mercury Speciation in Gold Mining Tailings: Implications for Environmental Contamination in the Amazon. TOXICS 2024; 12:326. [PMID: 38787105 PMCID: PMC11125949 DOI: 10.3390/toxics12050326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/06/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
Artisanal small-scale gold mining (ASGM), an increasingly prevalent activity in South America, generates mercury-contaminated tailings that are often disposed of in the environment, leading to the introduction of mercury into ecosystems and the food web, where it bioaccumulates. Therefore, studying the geochemical processes involved in the desorption and dissolution of mercury in these tailings is essential for critical risk evaluations in the short and long term. For this purpose, sequential extraction procedures (SEPs) can be useful because they help to identify the phases to which Hg is associated, although they also have limitations such as a lack of selectivity and specificity. In this work, we propose a modified four-step SEP: exchangeable mercury (F1), oxidizable mercury (F2), mercury bound to Fe oxides (F3), and strongly bound mercury (F4). To test this adapted sequential extraction method, we evaluated the Hg contamination in mercury-contaminated tailings of the Amazon basin. The results revealed a total mercury concentration of 103 ± 16 mg·kg-1 in the tailings, with a significant portion in F1 (28% of the total), where Hg was bioavailable. The large Hg concentration in F3 (36%) suggested that Fe oxides likely contribute to mercury retention. Together, the SEP results emphasize the urgent need for improved surveillance of gold mining activities and responsible tailings management practices to mitigate environmental contamination and safeguard the health of the Amazon ecosystem.
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Affiliation(s)
| | - Jeremie Garnier
- Institute of Geosciences, University of Brasília, Asa Norte, Brasilia 70910-900, Brazil; (J.G.); (M.d.S.T.); (H.L.R.)
| | - Julia Mançano Quintarelli
- Institute of Geosciences, University of Brasília, Asa Norte, Brasilia 70910-900, Brazil; (J.G.); (M.d.S.T.); (H.L.R.)
| | - Myller de Sousa Tonhá
- Institute of Geosciences, University of Brasília, Asa Norte, Brasilia 70910-900, Brazil; (J.G.); (M.d.S.T.); (H.L.R.)
| | - Henrique Llacer Roig
- Institute of Geosciences, University of Brasília, Asa Norte, Brasilia 70910-900, Brazil; (J.G.); (M.d.S.T.); (H.L.R.)
| | - Patrick Seyler
- HydroSciences Montpellier, Université de Montpellier, Institut de Recherche Our le Développement, Centre National de la Recherche Scientifique, 34090 Montpellier, France;
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Zhang C, Xia T, Zhang L, Chen Z, Zhang H, Jia X, Jia L, Zhu X, Li G. Mercury pollution risks of agricultural soils and crops in mercury mining areas in Guizhou Province, China: effects of large mercury slag piles. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:53. [PMID: 38245580 DOI: 10.1007/s10653-023-01841-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024]
Abstract
The historical large mercury slag piles still contain high concentrations of mercury and their impact on the surrounding environment has rarely been reported. In this study, three different agricultural areas [the area with untreated piles (PUT), the area with treated piles (PT), and the background area with no piles (NP)] were selected to investigate mercury slag piles pollution in the Tongren mercury mining area. The mercury concentrations of agricultural soils ranged from 0.42 to 155.00 mg/kg, determined by atomic fluorescence spectrometry of 146 soil samples; and mercury concentrations in local crops (rice, maize, pepper, eggplant, tomato and bean) all exceeded the Chinese food safety limits. Soil and crop pollution trends in the three areas were consistent as PUT > PT > NP, indicating that mercury slag piles have exacerbated pollution. Mercury in the slag piles was adsorbed by multiple pathways of transport into soils with high organic matter, which made the ecological risk of agricultural soils appear extremely high. The total hazard quotients for residents from ingesting mercury in these crops were unacceptable in all areas, and children were more likely to be harmed than adults. Compared to the PT area, treatment of slag piles in the PUT area may decrease mercury concentrations in paddy fields and dry fields by 46.02% and 70.36%; further decreasing health risks for adults and children by 47.06% and 79.90%. This study provided a scientific basis for the necessity of treating large slag piles in mercury mining areas.
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Affiliation(s)
- Chengcheng Zhang
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Tianxiang Xia
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China.
| | - Lina Zhang
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China.
- School of Environment, Beijing Normal University, Beijing, 100875, China.
| | - Zhuo Chen
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Haonan Zhang
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Xiaoyang Jia
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Lin Jia
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Xiaoying Zhu
- National Engineering Research Center of Urban Environmental Pollution Control, Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites, Beijing Municipal Research Institute of Eco-Environmental Protection, Beijing, 100037, China
| | - Guangbing Li
- Tongren Environmental Science and Technology Consulting Center, Tongren, 554399, China
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Phengsaart T, Srichonphaisan P, Kertbundit C, Soonthornwiphat N, Sinthugoot S, Phumkokrux N, Juntarasakul O, Maneeintr K, Numprasanthai A, Park I, Tabelin CB, Hiroyoshi N, Ito M. Conventional and recent advances in gravity separation technologies for coal cleaning: A systematic and critical review. Heliyon 2023; 9:e13083. [PMID: 36793968 PMCID: PMC9922934 DOI: 10.1016/j.heliyon.2023.e13083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
"Affordable and clean energy" is enshrined in the UN Sustainable Development Goals (SDGs; #7) because of its importance in supporting the sustainable development of society. As an energy source, coal is widely used because it is abundant and its utilization for electricity and heat generation do not require complex infrastructures and technologies, which makes it ideal for the energy needs of low-income and developing countries. Coal is also essential in steel making (as coke) and cement production and will continue to be on high demand for the foreseeable future. However, coal is naturally found with impurities or gangue minerals like pyrite and quartz that could create by-products (e.g., ash) and various pollutants (e.g., CO2, NOX, SOX). To reduce the environmental impacts of coal during combustion, coal cleaning-a kind of pre-combustion clean coal technology-is essential. Gravity separation, a technique that separates particles based on their differences in density, is widely used in coal cleaning due to the simplicity of its operation, low cost, and high efficiency. In this paper, recent studies (from 2011 to 2020) related to gravity separation for coal cleaning were systematically reviewed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 1864 articles were screened after removing duplicates, and after a thorough evaluation 189 articles were reviewed and summarized. Among of conventional separation techniques, dense medium separator (DMS), particularly dense medium cyclone (DMC), is the most popular technologies studied, which could be attributed to the growing challenges of cleaning/processing fine coal-bearing materials. In recent years, most of works focused on the development of dry-type gravity technologies for coal cleaning. Finally, gravity separation challenges and future applications to address problems in environmental pollution and mitigation, waste recycling and reprocessing, circular economy, and mineral processing are discussed.
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Affiliation(s)
- Theerayut Phengsaart
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand,Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan,Corresponding author. Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Palot Srichonphaisan
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Chinawich Kertbundit
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Natatsawas Soonthornwiphat
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Somthida Sinthugoot
- Department of Groundwater Resources, Ministry of Natural Resources and Environment, Bangkok 10900, Thailand
| | - Nutthakarn Phumkokrux
- Department of Geography, Faculty of Education, Ramkhamhaeng University, Bangkok 10240, Thailand,Department of Earth Sciences, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Onchanok Juntarasakul
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kreangkrai Maneeintr
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Apisit Numprasanthai
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Carlito Baltazar Tabelin
- Department of Materials and Resources Engineering Technology, College of Engineering and Technology, Mindanao State University-Iligan Institute of Technology, Iligan City 9200, Philippines
| | - Naoki Hiroyoshi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Mayumi Ito
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
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Tabelin CB, Uyama A, Tomiyama S, Villacorte-Tabelin M, Phengsaart T, Silwamba M, Jeon S, Park I, Arima T, Igarashi T. Geochemical audit of a historical tailings storage facility in Japan: Acid mine drainage formation, zinc migration and mitigation strategies. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129453. [PMID: 35797786 DOI: 10.1016/j.jhazmat.2022.129453] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/14/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Historical tailings storage facilities (TSFs) are either abandoned or sparsely rehabilitated promoting acid mine drainage (AMD) formation and heavy metal release. To sustainably manage these sites, a geochemical audit coupled with numerical simulation to predict AMD flow paths and heavy metal migration are valuable. In this study, a 40-year-old TSF in Hokkaido, Japan was investigated. Tailings in this historical TSF contain pyrite (FeS2) while its copper (Cu) and zinc (Zn) contents were 1400-6440 mg/kg and 2800-22,300 mg/kg, respectively. Copper and Zn were also easily released in leaching tests because they are partitioned with the exchangeable phase (29% of Zn; 15% of Cu) and oxidizable fraction (25% of Zn; 33% of Cu). Kinetic modeling results attributed AMD formation to the interactions of pyrite and soluble phases in the tailings with oxygenated groundwater, which is supported by the sequential extraction and leaching results. Calibrations of groundwater/AMD flow and solute transport in the 2D reactive transport model were successfully done using hydraulic heads measured on-site and leaching results, respectively. The model forecasted the quality of AMD to deteriorate with time and AMD formation to continue for 1000 years. It also predicted ~24% AMD flux reduction, including lower Zn release with time when recharge reduction interventions are implemented on-site.
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Affiliation(s)
- Carlito Baltazar Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia.
| | - Asuka Uyama
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Shingo Tomiyama
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines; Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Theerayut Phengsaart
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
| | - Marthias Silwamba
- Department of Metallurgical Engineering, School of Mines, University of Zambia, Lusaka, Zambia
| | - Sanghee Jeon
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Takahiko Arima
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Toshifumi Igarashi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
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Pelcová P, Grmela J, Ridošková A, Kopp R, Hrůzová M, Malý O. Trophic distribution of mercury from an abandoned cinnabar mine within the Záskalská reservoir ecosystem (Czech Republic). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:61383-61396. [PMID: 35445304 DOI: 10.1007/s11356-022-20159-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
The distribution of mercury species was studied in all aquatic ecosystem components (i.e., water, sediment, emergent aquatic plants, invertebrates and omnivorous and piscivorous fish) of the Záskalská water reservoir (Central Bohemia, Czech Republic) which is in the vicinity of an abandoned cinnabar mine. The results indicate that the transport of mercury from the cinnabar mine is the major source of mercury in the Záskalská reservoir. The legal maximum limit (0.07 μg/L) for total mercury concentration in water samples was exceeded only during rainy periods. The total mercury concentration in the surface sediments was in the range from 0.22 to 9.19 mg/kg in dry matter (up to 0.2% CH3Hg+) and was sample site-specific. The dominant form of mercury in sediments was mercury sulphide (22.9-79.2%). The emergent macrophytes accumulated mercury primarily by the roots from sediments, and no significant translocation of mercury to leaves was observed. The legal maximum limit for mercury content in fish muscle (0.5 mg/kg in the fresh matter) was exceeded up to 4.48 times for piscivorous fish. Hazard index values indicate a health risk concern for children and for people consuming more than 100 g of fish muscle per day. Our results emphasise the need to implement legal restrictions on the consumption of piscivorous fish caught in ecosystems downstream of abandoned cinnabar mines.
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Affiliation(s)
- Pavlína Pelcová
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic.
| | - Jan Grmela
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic
| | - Andrea Ridošková
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic
| | - Radovan Kopp
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic
| | - Marie Hrůzová
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic
| | - Ondřej Malý
- Department of Zoology, Fisheries, Hydrobiology and Apiculture, Mendel University in Brno, Zemedelska 1, 61300, Brno, Czech Republic
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The Effects of Coexisting Copper, Iron, Cobalt, Nickel, and Zinc Ions on Gold Recovery by Enhanced Cementation via Galvanic Interactions between Zero-Valent Aluminum and Activated Carbon in Ammonium Thiosulfate Systems. METALS 2021. [DOI: 10.3390/met11091352] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of galvanic interactions between zero-valent aluminum (ZVAl) and activated carbon (AC) to recover gold (Au) ions is a promising technique to overcome the challenges due to the poor recovery in ammonium thiosulfate systems, but the applicability to practical Au ore processing remains elusive so far. The present study describes (1) the recovery of Au ions from low Au concentrations, which are typical concentrations used in Au ore processing; and (2) an investigation into the effects of various coexisting base metal ions that can be present in pregnant ore-leached solutions. The results showed that high Au recovery (i.e., over 85%) was obtained even at low Au concentrations under the following conditions: 1:1 of 0.15 g of ZVAl and AC with 10 mL of ammonium thiosulfate solution containing 5 mg/L of Au ions at 25 °C for 1 h in an anoxic atmosphere. Selected coexisting metal ions (i.e., copper, iron, cobalt, nickel, and zinc) were studied to establish their effects on Au recovery, and the results showed that the Au recovery was enhanced (about 90%) when copper ions coexist in the solution with minimal effects from other competing base metal ions.
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Opiso EM, Tabelin CB, Maestre CV, Aseniero JPJ, Park I, Villacorte-Tabelin M. Synthesis and characterization of coal fly ash and palm oil fuel ash modified artisanal and small-scale gold mine (ASGM) tailings based geopolymer using sugar mill lime sludge as Ca-based activator. Heliyon 2021; 7:e06654. [PMID: 33869866 PMCID: PMC8042442 DOI: 10.1016/j.heliyon.2021.e06654] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/29/2020] [Accepted: 03/29/2021] [Indexed: 11/30/2022] Open
Abstract
The continuous accumulation of artisanal and small-scale gold mining (ASGM) tailings in the Philippines without adequate storage and disposal facility could lead to human health and environmental disasters in the long run. In this study, ASGM tailings was simultaneously stabilized and repurposed as construction material via geopolymerization using coal fly ash, palm oil fuel ash and a powder-based alkali activator. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) identified iron sulfides in the tailings containing arsenic (As), cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn), which could be released via weathering. The average unconfined compressive strengths (UCS) of tailings-based geopolymers at 14 days curing were 7.58 MPa and 7.7 MPa with fly ash and palm oil fuel ash, respectively. The tailings-based geopolymers with palm oil fuel ash had higher UCS most likely due to CASH reaction product formation that improved strength formation. The toxicity characteristic leaching procedure (TCLP) results showed very low leachabilities of As, Pb and Fe in the geopolymer materials suggesting ASGM tailings was effectively encapsulated within the geopolymer matrix. Overall, the geopolymerization of ASGM tailings is a viable and promising solution to simultaneously stabilize mining and industrial wastes and repurpose them into construction materials.
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Affiliation(s)
- Einstine M Opiso
- Geo-environmental Engineering Group, Civil Engineering Department, Central Mindanao University, Bukidnon, Philippines
| | - Carlito B Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Christian V Maestre
- Materials Science Research Group, Physics Department, Central Mindanao University, Bukidnon, Philippines
| | - John Paul J Aseniero
- Materials Science Research Group, Physics Department, Central Mindanao University, Bukidnon, Philippines
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
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Gamboa-Herrera JA, Ríos-Reyes CA, Vargas-Fiallo LY. Mercury speciation in mine tailings amended with biochar: Effects on mercury bioavailability, methylation potential and mobility. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143959. [PMID: 33348158 DOI: 10.1016/j.scitotenv.2020.143959] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/08/2020] [Accepted: 11/14/2020] [Indexed: 06/12/2023]
Abstract
Biochar is a low-cost and environmentally friendly amendment with strong ability for adsorption of mercury (Hg) from aqueous solutions, contaminated soils, and sediments. In the present study, six biochars were prepared from the pyrolysis of cocoa pod husk, sugarcane bagasse and banana pseudostem at 400 and 600 °C in order to use them as an organic amendment and to evaluate their capacities to reduce the bioavailability, methylation potential, and mobility of Hg present in mine tailings without environmental treatment. To quantify the effects of each variety of biochar, incubation experiments of soil were established by mixing mine tailings with 5% by weight of biochar for 90 days. Once the incubation time concluded, sequential extraction procedures were carried out to determine the fractionation of the Hg species. Speciation analysis results indicated that the remedial effects of biochar depended on the source of organic matter and pyrolysis temperature. The bioavailable and organic Hg fractions decreased respectively by up to 75 and 79%, indicating a methylation potential reduction. Immobile Hg fraction increased to 76% with respect to the control. Adsorption and stabilization to HgS from the soluble forms of Hg reduce the percentage of bioavailable Hg. The organic Hg fraction reduction was correlated with the decrease of the bioavailable Hg fraction and with direct adsorption processes in the biochar structure. Highly porous biochars developed at high temperature, with large contents of superficial polar functional groups (H/C), and high pH, electrical conductivity, ash percentage and cation exchange capacity values favor the stabilization and adsorption of Hg in mine tailings. In summary, the application of biochar could be an effective method for the remediation of Hg-contaminated mine tailings, transforming the Hg species into less toxic, soluble, reactive, and bioavailable forms.
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Affiliation(s)
- J A Gamboa-Herrera
- Escuela de Geología, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - C A Ríos-Reyes
- Escuela de Geología, Universidad Industrial de Santander, Bucaramanga 680002, Colombia.
| | - L Y Vargas-Fiallo
- Escuela de Química, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
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Mineralogical and Geochemical Characterization of Gold Mining Tailings and Their Potential to Generate Acid Mine Drainage (Minas Gerais, Brazil). MINERALS 2020. [DOI: 10.3390/min11010039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For more than 30 years, sulfide gold ores were treated in metallurgic plants located in Nova Lima, Minas Gerais, Brazil, and accumulated in the Cocoruto tailings dam. Both flotation and leaching tailings from a deactivated circuit, as well as roasted and leaching tailings from an ongoing plant, were studied for their acid mine drainage potential and elements’ mobility. Detailed characterization of both tailings types indicates the presence of fine-grain size material hosting substantial amounts of sulfides that exhibit distinct geochemical and mineralogical characteristics. The samples from the ongoing plant show high grades of Fe in the form of oxides, cyanide, and sulfates. Differently, samples from the old circuit shave higher average concentrations of Al (0.88%), Ca (2.4%), Mg (0.96%), and Mn (0.17%), present as silicates and carbonates. These samples also show relics of preserved sulfides, such as pyrite and pyrrhotite. Concentrations of Zn, Cu, Au, and As are higher in the tailings of the ongoing circuit, while Cr and Hg stand out in the tailings of the deactivated circuit. Although the obtained results show that the sulfide wastes do not tend to generate acid mine drainage, leaching tests indicate the possibility of mobilization of toxic elements, namely As and Mn in the old circuit, and Sb, As, Fe, Ni, and Se in the tailings of the plant that still works. This work highlights the need for proper management and control of tailing dams even in alkaline drainage environments such as the one of the Cocoruto dam. Furthermore, strong knowledge of the tailings’ dynamics in terms of geochemistry and mineralogy would be pivotal to support long-term decisions on wastes management and disposal.
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Tabelin CB, Silwamba M, Paglinawan FC, Mondejar AJS, Duc HG, Resabal VJ, Opiso EM, Igarashi T, Tomiyama S, Ito M, Hiroyoshi N, Villacorte-Tabelin M. Solid-phase partitioning and release-retention mechanisms of copper, lead, zinc and arsenic in soils impacted by artisanal and small-scale gold mining (ASGM) activities. CHEMOSPHERE 2020; 260:127574. [PMID: 32688316 PMCID: PMC7351430 DOI: 10.1016/j.chemosphere.2020.127574] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/23/2020] [Accepted: 06/29/2020] [Indexed: 05/28/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) operations are major contributors to the Philippines' annual gold (Au) output (at least 60%). Unfortunately, these ASGM activities lacked adequate tailings management strategies, so contamination of the environment is prevalent. In this study, soil contamination with copper (Cu), lead (Pb), zinc (Zn) and arsenic (As) due to ASGM activities in Nabunturan, Davao de Oro, Philippines was investigated. The results showed that ASGM-impacted soils had Cu, Pb, Zn and As up to 3.6, 83, 73 and 68 times higher than background levels, respectively and were classified as 'extremely' polluted (CD = 30-228; PLI = 5.5-34.8). Minerals typically found in porphyry copper-gold ores like pyrite, chalcopyrite, malachite, galena, sphalerite and goethite were identified by XRD and SEM-EDS analyses. Furthermore, sequential extraction results indicate substantial Cu (up to 90%), Pb (up to 50%), Zn (up to 65%) and As (up to 48%) partitioned with strongly adsorbed, weak acid soluble, reducible and oxidisable fractions, which are considered as 'geochemically mobile' phases in the environment. Although very high Pb and Zn were found in ASGM-impacted soils, they were relatively immobile under oxidising conditions around pH 8.5 because of their retention via adsorption to hydrous ferric oxides (HFOs), montmorillonite and kaolinite. In contrast, Cu and As release from the historic ASGM site samples exceeded the environmental limits for Class A and Class C effluents, which could be attributed to the removal of calcite and dolomite by weathering. The enhanced desorption of As at around pH 8.5 also likely contributed to its release from these soils.
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Affiliation(s)
- Carlito Baltazar Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia.
| | - Marthias Silwamba
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Florifern C Paglinawan
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Alissa Jane S Mondejar
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Ho Gia Duc
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Vannie Joy Resabal
- Department of Materials and Resources Engineering and Technology, College of Engineering and Technology, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Einstine M Opiso
- Geo-environmental Engineering Research Group, Civil Engineering Department, Central Mindanao University, Bukidnon, Philippines
| | - Toshifumi Igarashi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Shingo Tomiyama
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mayumi Ito
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Naoki Hiroyoshi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines; Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines.
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Improved pyrolysis behavior of ammonium polyphosphate-melamine-expandable (APP-MEL-EG) intumescent fire retardant coating system using ceria and dolomite as additives for I-beam steel application. Heliyon 2019; 6:e03119. [PMID: 31909279 PMCID: PMC6940668 DOI: 10.1016/j.heliyon.2019.e03119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/05/2019] [Accepted: 12/20/2019] [Indexed: 11/28/2022] Open
Abstract
This study describes the effects of ceria (CeO2) and dolomite [CaMg(CO3)2] additives on the pyrolysis behavior and fire resistive property of conventional intumescent flame retardant (IFR) coating system for I-beam steel substrate called ammonium polyphosphate-melamine-expandable graphite (APP-MEL-EG) system. The fire resistance of various formulations was evaluated using the standard vertical Bunsen burner fire test. Thermogravimetric analysis (TGA) was used to understand the degradation of coating formulations. Observations by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) demonstrated that significant amounts of additives favored the formation of homogeneous compacted char structures, which were predominantly composed of carbon (C), phosphorus (P) and oxygen (O). These three main components of the char were also found to be in various binding combinations with other lighter elements like nitrogen (N) and hydrogen (H) as illustrated by the attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy results. X-ray photoelectron spectroscopy (XPS) further suggest that polyethylene([(CH2–C2H2–CH2)n−]) free radicals were abundant on the char surface for the two best formulations and the binding energy of this radical promoted the formation of aromatic carbon chains that enhanced the char's thermal stability. This means that the selection of appropriate additives and combinations of flame-retardant ingredients could significantly change the morphology of the char layer and improve its thermal stability during fire exposure.
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Tabelin CB, Igarashi T, Villacorte-Tabelin M, Park I, Opiso EM, Ito M, Hiroyoshi N. Arsenic, selenium, boron, lead, cadmium, copper, and zinc in naturally contaminated rocks: A review of their sources, modes of enrichment, mechanisms of release, and mitigation strategies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:1522-1553. [PMID: 30248873 DOI: 10.1016/j.scitotenv.2018.07.103] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 07/01/2018] [Accepted: 07/05/2018] [Indexed: 05/28/2023]
Abstract
Massive and ambitious underground space development projects are being undertaken by many countries around the world to decongest megacities, improve the urban landscapes, upgrade outdated transportation networks, and expand modern railway and road systems. A number of these projects, however, reported that substantial portions of the excavated debris are oftentimes naturally contaminated with hazardous elements, which are readily released in substantial amounts once exposed to the environment. These contaminated excavation debris/spoils/mucks, loosely referred to as "naturally contaminated rocks", contain various hazardous and toxic inorganic elements like arsenic (As), selenium (Se), boron (B), and heavy metals like lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn). If left untreated, these naturally contaminated rocks could pose very serious problems not only to the surrounding ecosystem but also to people living around the construction and disposal sites. Several incidents of soil and ground/surface water contamination, for example, have been documented due to the false assumption that excavated materials are non-hazardous because they only contain background levels of environmentally regulated elements. Naturally contaminated rocks are hazardous wastes, but they still remain largely unregulated. In fact, standard leaching tests for their evaluation and classification are not yet established. In this review, we summarized all available studies in the literature about the factors and processes crucial in the enrichment, release, and migration of the most commonly encountered hazardous and toxic elements in naturally contaminated geological materials. Although our focus is on naturally contaminated rocks, analogue systems like contaminated soils, sediments, and other hazardous wastes that have been more widely studied will also be discussed. Classification schemes and leaching tests to properly identify and regulate excavated rocks that may potentially pose environmental problems will be examined. Finally, management and mitigation strategies to limit the negative effects of these hazardous wastes are introduced.
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Affiliation(s)
- Carlito Baltazar Tabelin
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
| | - Toshifumi Igarashi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Mylah Villacorte-Tabelin
- Department of Biological Sciences, College of Science and Mathematics, Mindanao State University - Iligan Institute of Technology, Iligan City 9200, Philippines
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Einstine M Opiso
- Geoenvironmental Engineering Group, Central Mindanao University, Maramag 8710, Bukidnon, Philippines
| | - Mayumi Ito
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Naoki Hiroyoshi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
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Potential utilization of artisanal gold-mine tailings as geopolymeric source material: preliminary investigation. SN APPLIED SCIENCES 2018. [DOI: 10.1007/s42452-018-0045-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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