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Bediako JK, Kudoahor E, Lim CR, Affrifah NS, Kim S, Song MH, Repo E. Exploring the insights and benefits of biomass-derived sulfuric acid activated carbon for selective recovery of gold from simulated waste streams. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 177:135-145. [PMID: 38325014 DOI: 10.1016/j.wasman.2024.02.002] [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: 08/25/2023] [Revised: 01/06/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
The surging affluent in society, concomitant with increasing global demand for electrical and electronic devices, has led to a sharp rise in e-waste generation. E-wastes contain significant amounts of precious metals, such as gold, which can be recovered and reused, thus reducing the environmental impact of mining new metals. Selective recovery using sustainable and cost-effective materials and methods is therefore vital. This study undertook a detailed evaluation of low-cost biomass-derived activated carbon (AC) for selective recovery of Au from simulated e-waste streams. Utilizing high-performance synthesized H2SO4-AC, the adsorption mechanisms were explicated through a combination of characterization techniques, i.e., FE-SEM, BET, TGA, XRD, FTIR, XPS, and DFT simulations to conceptualize the atomic and molecular level interactions. Optimization of coordination geometries between model H2SO4-AC and anionic complexes revealed the most stable coordination for AuCl4- (binding energy, Eb = -4064.15 eV). The Au selectivity was further enhanced by reduction of Au(III) to Au(0), as determined by XRD and XPS. The adsorption reaction was relatively fast (∼5h), and maximum Au uptake reached 1679.74 ± 37.66 mg/g (among highest), achieved through adsorption isotherm experiments. Furthermore, a mixture of 0.5 M thiourea/1 M HCl could effectively elute the loaded Au and regenerate the spent AC. This study presents radical attempts to examine in detail, the synergistic effects of H2SO4 activation on biomass-derived ACs for selective recovery of Au from complex mixtures. The paper therefore describes a novel approach for the selective recovery of Au from e-wastes using multifunctional biomass-derived H2SO4-AC.
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Affiliation(s)
- John Kwame Bediako
- Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology (LUT), FI-53850, Lappeenranta, Finland; Department of Food Process Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, P. O. Box LG 77, Legon, Accra, Ghana.
| | - Enoch Kudoahor
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Che-Ryong Lim
- Division of Semiconductor and Chemical Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Nicole Sharon Affrifah
- Department of Food Process Engineering, School of Engineering Sciences, College of Basic and Applied Sciences, University of Ghana, P. O. Box LG 77, Legon, Accra, Ghana
| | - Sok Kim
- Division of Environmental Science & Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Myung-Hee Song
- Division of Semiconductor and Chemical Engineering, Jeonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Eveliina Repo
- Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology (LUT), FI-53850, Lappeenranta, Finland
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Zhang L, Djellabi R, Su P, Wang Y, Zhao J. Through converting the surface complex on TiO 2 nanorods to generate superoxide and singlet oxygen to remove CN . J Environ Sci (China) 2023; 124:300-309. [PMID: 36182139 DOI: 10.1016/j.jes.2021.08.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/16/2021] [Accepted: 08/30/2021] [Indexed: 06/16/2023]
Abstract
Cyanide (CN-) is extensively used in the process of plating devices and for surface treatment in the electroplating industry and is extremely hazardous to humans and the environment. Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) hold considerable promise for CN- removal. However, the activity of sulfate radical and hydroxyl radical generated in the PMS activation process is low in the base condition, leading to a drop in its efficiency in CN- removal. Thus, a photo-electrocatalytic system (PEC), developed using a TiO2 photoanode and a carbon aerogel cathode, was used to activate PMS for the removal of CN- from wastewater through the generation of radicals and non-radicals. The PEC/PMS system could effectively remove CN-, with the removal efficiency reaching 98.5% within 2 min, when PMS concentration was at the 0.25 mmol/L level, and the applied bias voltage was -0.5 V. The main active species in the PEC/PMS system were superoxide radicals and singlet oxygen, which was proved through electron paramagnetic resonance detection and quenching experiments. Results obtained through in-situ Raman measurements, photocurrent tests, and electrochemical impedance spectroscopy measurements indicated that the TiO2 could activate PMS to generate active species. Following many cycles of experimentation, it was discovered that the system displayed high catalytic performance and possessed satisfactory stability to remove CN- economically and efficiently.
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Affiliation(s)
- Laiqi Zhang
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China; Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ridha Djellabi
- Dip. Chimica and INSTM-UdR Milano, Università degli Studi di Milano, Via Golgi, 19 20133 Milano, Italy
| | - Peidong Su
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yan Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Jianling Zhao
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China.
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Wang L, An X, Xiao X, Li N, Xie D, Lai F, Zhang Q. Treatment of thiocyanate-containing wastewater: a critical review of thiocyanate destruction in industrial effluents. World J Microbiol Biotechnol 2022; 39:35. [PMID: 36469179 DOI: 10.1007/s11274-022-03481-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/23/2022] [Indexed: 12/09/2022]
Abstract
Thiocyanate is a common pollutant in gold mine, textile, printing, dyeing, coking and other industries. Therefore, thiocyanate in industrial wastewater is an urgent problem to be solved. This paper reviews the chemical properties, applications, sources and toxicity of thiocyanate, as well as the various treatment methods for thiocyanate in wastewater and their advantages and disadvantages. It is emphasized that biological systems, ranging from laboratory to full-scale, are able to successfully remove thiocyanate from factories. Thiocyanate-degrading microorganisms degrade thiocyanate in autotrophic manner for energy, while other biodegrading microorganisms use thiocyanate as a carbon or nitrogen source, and the biochemical pathways and enzymes involved in thiocyanate metabolism by different bacteria are discussed in detail. In the future, degradation mechanisms should be investigated at the molecular level, with further research aiming to improve the biochemical understanding of thiocyanate metabolism and scaling up thiocyanate degradation technologies from the laboratory to a full-scale.
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Affiliation(s)
- Liuwei Wang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Xuejiao An
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Xiaoshuang Xiao
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Ningjian Li
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Dong Xie
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Fenju Lai
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China
| | - Qinghua Zhang
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang, 330045, People's Republic of China.
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Eco-friendly and rapid extraction of gold by in-situ catalytic oxidation with N-bromosuccinimide. Heliyon 2022; 8:e09706. [PMID: 35756117 PMCID: PMC9213721 DOI: 10.1016/j.heliyon.2022.e09706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/06/2022] [Accepted: 06/07/2022] [Indexed: 11/20/2022] Open
Abstract
Gold is a valued, critical element whose chemical activation or extraction is challenging. Non-cyanide extraction of gold is now the focus, and N-bromosuccinimide(NBS) is attracting attention. Herein, new insights into the possible mechanism are deeply revealed through comprehensive analysis and detection of the reaction by using elementary gold and gold bearing ore. Experiments on gold foil indicate that Au can be activated in NBS solution to perform a satisfactory dissolution. Application of NBS in gold extraction from ore show a high yield of 86.24% under optimal conditions of NBS dosage 0.05 M, liquid-solid ratio 4:1, stirring speed 400 rpm, pH 8, 25 °C and leaching for 20 h, while yields of other coexisting metals are nearly negligible. The process leads to direct, efficient, one-pot conversion of gold, into simple water-soluble salts. Characterizations show that the framework of NBS are not destroyed, only bromine separates from the framework. The oxidation of neutral gold atom to trivalent Au(III) occurs in a mild, clean and room-temperature chemistry, which converts gold to [AuBr4]-, and the framework to succinimide. The active bromine and radical Br (Br•) generated from in-situ autocatalysis of NBS are responsible for this. The systematic results herald a green procedure for preparation of gold derivatives and gold extraction industry. Utilizing nitrogen heterocyclic to carry bromine and sustainably release Br• to in situ catalytically oxidize gold. One-pot conversion and high-efficient option to extract gold in a mild, clean and room-temperature chemistry. Bromine separates from NBS skeleton to generate Br• and active Br2 and rapidly oxidized Au0 to Au3+ to form stable complex compound [AuBr4]-. High Au leaching selectivity with 86.24% yield by 0.05 M NBS and nearly negligible yields of other coexisting metals.
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Robshaw TJ, Turner J, Kearney S, Walkley B, Sharrad CA, Ogden MD. Capture of aqueous radioiodine species by metallated adsorbents from wastestreams of the nuclear power industry: a review. SN APPLIED SCIENCES 2021. [DOI: 10.1007/s42452-021-04818-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Abstract
Abstract
Iodine-129 poses a significant challenge in the drive towards lowering radionuclide emissions from used nuclear fuel recycling operations. Various techniques are employed for capture of gaseous iodine species, but it is also present, mainly as iodide anions, in problematic residual aqueous wastestreams, which have stimulated research interest in technologies for adsorption and retention of the radioiodine. This removal effort requires specialised adsorbents, which use soft metals to create selectivity in the challenging chemical conditions. A review of the literature, at laboratory scale, reveals a number of organic, inorganic and hybrid adsorbent matrices have been investigated for this purpose. They are functionalised principally by Ag metal, but also Bi, Cu and Pb, using numerous synthetic strategies. The iodide capacity of the adsorbents varies from 13 to 430 mg g−1, with ion-exchange resins and titanates displaying the highest maximum uptakes. Kinetics of adsorption are often slow, requiring several days to reach equilibrium, although some ligated metal ion and metal nanoparticle systems can equilibrate in < 1 h. Ag-loaded materials generally exhibit superior selectivity for iodide verses other common anions, but more consideration is required of how these materials would function successfully in industrial operation; specifically their performance in dynamic column experiments and stability of the bound radioiodine in the conversion to final wasteform and subsequent geological storage.
Article highlights
Metallated adsorbents for the capture and retention of radioiodine in the nuclear industry are assessed.
The strengths and weaknesses of organic, inorganic and hybrid support matrices and loading mechanisms are discussed.
Pathways for progression of this technology are proposed.
Graphic abstract
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Azizitorghabeh A, Mahandra H, Ramsay J, Ghahreman A. Gold Leaching from an Oxide Ore Using Thiocyanate as a Lixiviant: Process Optimization and Kinetics. ACS OMEGA 2021; 6:17183-17193. [PMID: 34278105 PMCID: PMC8280645 DOI: 10.1021/acsomega.1c00525] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/11/2021] [Indexed: 05/31/2023]
Abstract
Thiocyanate (SCN-) is a promising alternative to cyanide as a lixiviant for gold extraction and is 1000 times less toxic than cyanide. In this study, the following leaching parameters were tested to optimize the gold recovery for the first time from an oxide ore using the response surface methodology: initial thiocyanate concentration (10-500 mM), initial Fe3+ concentration (10-500 mM), and pulp density (10-50% w/v). The maximum gold recovery (96%) was achieved with 500 mM thiocyanate, 100 mM Fe3+, and 50% pulp density at 25 °C and pH = 2 for 24 h. A kinetic study on the optimum leaching condition showed that it followed the shrinking core model, in which the rate-controlling mechanism was the diffusion process. These results are discussed in the context of the published literature.
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Affiliation(s)
- Atefeh Azizitorghabeh
- Hydrometallurgy
and Environment Laboratory, Robert M. Buchan Department of Mining, Queen’s University, 25 Union Street, Kingston, Ontario K7L 3N6, Canada
| | - Harshit Mahandra
- Hydrometallurgy
and Environment Laboratory, Robert M. Buchan Department of Mining, Queen’s University, 25 Union Street, Kingston, Ontario K7L 3N6, Canada
| | - Juliana Ramsay
- Department
of Chemical Engineering, Queen’s
University, 19 Division
Street, Kingston, Ontario K7L 3N6, Canada
| | - Ahmad Ghahreman
- Hydrometallurgy
and Environment Laboratory, Robert M. Buchan Department of Mining, Queen’s University, 25 Union Street, Kingston, Ontario K7L 3N6, Canada
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