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Weiksnar KD, Lott DJ, Townsend TG. Blending phosphogypsum to mitigate radionuclide leaching for sustainable road base applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176628. [PMID: 39357760 DOI: 10.1016/j.scitotenv.2024.176628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2024] [Revised: 09/25/2024] [Accepted: 09/28/2024] [Indexed: 10/04/2024]
Abstract
Production of phosphoric acid generates a calcium sulfate byproduct known as phosphogypsum (PG). PG is not considered a suitable standalone road base material because of concerns such as strength and presence of radionuclides. This paper investigates the latter, specifically the influence of blending PG with common alkaline road base aggregates - limerock (LR) and recycled concrete aggregate (RCA) - on radionuclide leaching. Radionuclide leaching from several PG sources was assessed for gross alpha, gross beta, uranium, and combined radium (226 + 228). Solution pH affected Ra226 mobility, with minimum concentrations exhibited at a pH in the range of 6 to 8. Mobile Ra226 concentrations in RCA blends decreased compared to original PG; Ra226 mobility initially increased at low LR replacements but decreased with increasing mass of LR (50 %-75 %). The data suggest an additional mechanism beyond pH alone impacted Ra226 mobility from the blends, possibly the binding or substitution of radium by elevated concentrations of Ba, Sr, or Ca. Blending with RCA resulted in radionuclide concentrations below respective drinking water thresholds, mitigating leaching concern from PG-RCA road base blends. PG-LR blends can meet regulatory limits when incorporating appropriate PG sources, providing an avenue for PG-amended road base materials. The blending approach reduced Ra226 mobility from PG-amended base, accommodating more PG use, serving as an alternative scenario to end-of-life stacking.
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Affiliation(s)
- Kate D Weiksnar
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Dreyton J Lott
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA.
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Li K, Zhu L, Wu Z, Wang X. Properties of Cemented Filling Materials Prepared from Phosphogypsum-Steel Slag-Blast-Furnace Slag and Its Environmental Effect. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3618. [PMID: 39063909 PMCID: PMC11278685 DOI: 10.3390/ma17143618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 06/22/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024]
Abstract
Phosphogypsum (PG) occupies a large amount of land due to its large annual production and low utilization rate, and at the same time causes serious environmental problems due to toxic impurities. PG is used for mine backfill, and industrial solid waste is a curing agent for PG, which can save the filling cost and reduce environmental pollution. In this paper, PG was used as a raw material, combined with steel slag (SS) and ground granulated blast-furnace slag (GGBS) under the action of an alkali-activated agent (NaOH) to prepare all-solid waste phosphogypsum-based backfill material (PBM). The effect of the GGBS to SS ratio on the compressive strength and toxic leaching of PBM was investigated. The chemical composition of the raw materials was obtained by XRF analysis, and the mineral composition and morphology of PBM and its stabilization/curing mechanism against heavy metals were analyzed using XRD and SEM-EDS. The results showed that the best performance of PBM was achieved when the contents of PG, GGBS, and SS were 80%, 13%, and 7%, the liquid-to-solid ratio was 0.4, and the mass concentration of NaOH was 4%, with a strength of 2.8 MPa at 28 days. The leaching concentration of fluorine at 7 days met the standard of groundwater class IV (2 mg/L), and the leaching concentration of phosphorus was detected to be less than 0.001 mg/L, and the leaching concentration of heavy metals met the environmental standard at 14 d. The hydration concentration in PBM met the environmental standard. The hydration products in PBM are mainly ettringite and C-(A)-S-H gel, which can effectively stabilize the heavy metals in PG through chemical precipitation, physical adsorption, and encapsulation.
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Affiliation(s)
- Kai Li
- Guiyang Water Environment Group Co., Ltd., Guiyang 550025, China;
| | - Lishun Zhu
- College of Civil Engineering, Guizhou University, Guiyang 550025, China; (L.Z.); (Z.W.)
| | - Zhonghu Wu
- College of Civil Engineering, Guizhou University, Guiyang 550025, China; (L.Z.); (Z.W.)
| | - Xiaomin Wang
- College of Civil Engineering, Guizhou University, Guiyang 550025, China; (L.Z.); (Z.W.)
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Huang J, Liu Z, Wei X, Ding X, Zhu J, Zhao Y, Iqbal B, Guo S. Enhancing the Performance of Hemihydrate Phosphogypsum by the Collaborative Effects of Calcium Hydroxide and Carbonation. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2204. [PMID: 38793271 PMCID: PMC11122792 DOI: 10.3390/ma17102204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/01/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024]
Abstract
Normally, the acidic impurities in hemihydrate phosphogypsum (HPG) must be neutralized when HPG is utilized, and a little amount of calcium hydroxide (CH) is the best choice. In this paper, the effects of excessive CH (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.% of HPG) for carbonation curing on the performance of hardened HPG paste were studied. According to the results of macro tests and microanalyses of XRD, TG, SEM-EDS, MIP and N2 physisorption, it could be verified that CaF2, Ca3(PO4)2 and a large amount of nanoscale CaCO3 crystals were produced as a result of neutralization and carbonation, and the compressive strength and the water resistance of carbonated HPG + CH paste were significantly improved due to the effects of nanoscale CaCO3 crystals on pore refinement and the coverage on the surfaces of gypsum crystals of the hardened paste. Therefore, this study suggests a feasible and green method for recycling HPG/PG, with the collaborative effects of neutralization, performance enhancement and reductions in CO2 emissions.
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Affiliation(s)
- Jiawen Huang
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
| | - Zanqun Liu
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
| | - Xiangsong Wei
- Geology Institute of China Chemical Geology and Mine Bureau, Block B, No. 19, Xiaoying Road, Chaoyang District, Beijing 100101, China;
| | - Xiaojiang Ding
- Geology Institute of China Chemical Geology and Mine Bureau, Block B, No. 19, Xiaoying Road, Chaoyang District, Beijing 100101, China;
| | - Jiahui Zhu
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
| | - Yilin Zhao
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
| | - Babar Iqbal
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
| | - Shulai Guo
- School of Civil Engineering, Railway Campus, Central South University, No. 68, South Shaoshan Road, Tianxin District, Changsha 410018, China; (J.H.); (J.Z.); (Y.Z.); (B.I.); (S.G.)
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Essama Atenga JR, Tan Y, Deng Y, Wu J, Cai D, Li W. Influences of pretreatment methods on the mechanical and environmental behaviors of PG-GGBS-LM ternary stabilizer. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:37520-37531. [PMID: 38777972 DOI: 10.1007/s11356-024-33740-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
Phosphogypsum is a kind of acidic industrial byproducts with high content of soluble phosphorus and fluorine pollutants, which requires to be pretreated when used as cementitious material to (partial) replace traditional Portland cement. In this study, five different pretreatment methods were proposed for comparative analysis to examine the pretreatment effect on the mechanical and environmental behaviors of ternary phosphogypsum (PG), ground granulated blast-furnace slag (GGBS), and lime (LM) mixed stabilizer. Series laboratory tests, including unconfined compressive strength (UCS), pH, phosphorus (P)/fluorine (F) leaching, scanning electron microscopy (SEM), and X-ray diffraction (XRD) tests, were conducted to comprehend the macro- and microscopic mechanism. The results show that it is essential to grind raw PG to finer powdered state, so that it reacts more easily and quickly with LM and water. In addition, it was noticed that the UCS and P/F leaching concentration are not only affected by the mixing proportion of the PG-GGBS-LM ternary stabilizer, but also by the curing duration. The UCS increases rapidly from initial curing period and then grows slowly after 28 days of curing. From the perspective of strength evolution, mixing proportion of PG: GGBS: LM = 15:80:5 is optimal, but considering the economy and environmental related issues, PG: GGBS: LM = 30:65:5 was regarded as a more attractive choice. The findings can provide a reference for the selection of pretreatment methods and design of PG-based cementitious materials suited for stabilized soils.
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Affiliation(s)
| | - Yunzhi Tan
- College of Civil Engineering and Architecture, China Three Gorges University, Yichang, 443002, China
| | - Yongfeng Deng
- Department of Civil Engineering, Hubei University of Technology, Wuhan, 430068, China
- Institute of Geotechnical Engineering, School of Transportation, Southeast University, Nanjing, 211189, China
| | - Jun Wu
- College of Civil Engineering and Architecture, China Three Gorges University, Yichang, 443002, China.
| | - Dongming Cai
- College of Civil Engineering and Architecture, China Three Gorges University, Yichang, 443002, China
| | - Wenqi Li
- College of Civil Engineering and Architecture, China Three Gorges University, Yichang, 443002, China
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Meskini S, Mechnou I, Benmansour M, Remmal T, Samdi A. Environmental investigation on the use of a phosphogypsum-based road material: Radiological and leaching assessment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 345:118597. [PMID: 37480665 DOI: 10.1016/j.jenvman.2023.118597] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/13/2023] [Accepted: 07/04/2023] [Indexed: 07/24/2023]
Abstract
The transformation of phosphate ore into phosphoric acid results in the generation of high volumes of phosphogypsum (PG), an industrial by-product largely stockpiled worldwide. This solution, considered as the least damaging to the environment, constitutes a risk for the receiving environment due to the presence of harmful impurities such as heavy metals and radionuclides which hinder its large-scale valorization. This paper presents an environmental characterization of Moroccan phosphogypsum and an investigation on the environmental performance of a new lime (L) - fly ash (FA) treated phosphogypsum based road material. The concentration of metallic trace elements (Cr, Pb, Ni, Zn, Cu) in raw phosphogypsum ranged between 0.2 and 243 ppm, while its radioactivity reached 970 Bq/kg for Ra-226. The environmental performance of the proposed new road material (40% PG, 42% FA, 18% L) was evaluated using radiological risk indices besides static and dynamic leaching tests. The results showed a radioactivity reduction up to 82%, and an immobilization of metallic trace elements ranging from 25 to 100%. The stabilization/solidification mechanisms involved in the lime - fly ash treatment would be responsible for the fixation of these contaminants within the newly formed matrix.
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Affiliation(s)
- Sarra Meskini
- Laboratory of Geosciences Applied to Urban Development Engineering (GAIA), Ain Chock Faculty of Sciences, Hassan II University, Km 8 Route D'El Jadida, B.P 5366, Maarif 20100, Casablanca, Morocco.
| | - Issam Mechnou
- Laboratory of Materials Engineering for Environment and Valorization (GeMEV), Ain Chock Faculty of Sciences, Hassan II University, Km 8 Route D'El Jadida, B.P 5366, Maarif 20100, Casablanca, Morocco
| | - Moncef Benmansour
- National Center for Energy, Nuclear Sciences and Techniques, B.P. 1382, R.P. 10001, Rabat, Morocco
| | - Toufik Remmal
- Laboratory of Geosciences Applied to Urban Development Engineering (GAIA), Ain Chock Faculty of Sciences, Hassan II University, Km 8 Route D'El Jadida, B.P 5366, Maarif 20100, Casablanca, Morocco
| | - Azzeddine Samdi
- Laboratory of Materials and Environment Interface (LIME), Ain Chock Faculty of Sciences, Hassan II University, Km 8 Route D'El Jadida, B.P 5366, Maarif 20100, Casablanca, Morocco
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Yang G, Chen Z, Lv C, Deng L, Luo X, Li Y, He S, Liu Q. Preparation and Performance of H-PDMS/PMHS/OTS Hybrid Nanosilica Hydrophobic and Self-Cleaning Coatings on Phosphogypsum Surface. Polymers (Basel) 2023; 15:3574. [PMID: 37688197 PMCID: PMC10490376 DOI: 10.3390/polym15173574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Hemihydrate phosphogypsum, an industrial solid waste product of phosphoric acid production, is abundant and inexpensive. If the problem of poor water resistance is solved, this material could be substituted for cement and other traditional energy-consuming cementitious materials in the construction industry. This approach would confer important economic and environmental benefits while promoting the resource utilization of phosphogypsum (PG). In this study, hydrophobic and self-cleaning coatings of H-PDMS/PMHS/OTS hybrid nanosilica were prepared on a post-hydroxylated PG surface using sol-gel and impregnation methods. The water contact angle, Fourier-transform infrared spectroscopy, Three-dimensional surface morphology and roughness analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, surface abrasion tests, and tape adhesion tests were used to evaluate the hydrophobicity of the coatings. The results demonstrated that the in situ reaction produced a hydrophobic siloxane/nanosilica hybrid network that bonded to the PG surface via hydrogen bonding, making the otherwise completely hydrophilic PG hydrophobic (PGH-3, contact angle (CA) = 144.1°). The PGH-3 sample exhibited excellent chemical stability, maintaining a contact angle greater than 135° under strongly acidic or alkaline conditions. The contact angle remained at 123.7° after 50 tape-bonding tests. After 100 wear cycles, the contact angle remained at 121.9°. This study presents an environmentally friendly method and a straightforward application procedure to impart hydrophobicity to solid waste PG. Its potential is thus demonstrated in the field of PG-based construction materials and the comprehensive utilization of solid waste.
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Affiliation(s)
- Guang Yang
- College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China; (G.Y.)
| | - Zhonghua Chen
- Guizhou Phosphating Green Environmental Protection Industry Co., Ltd., Guiyang 551100, China
| | - Changwei Lv
- KZJ New Materials Group Guizhou Co., Ltd., Longli 551206, China
| | - Lei Deng
- KZJ New Materials Group Guizhou Co., Ltd., Longli 551206, China
| | - Xiaofeng Luo
- KZJ New Materials Group Guizhou Co., Ltd., Longli 551206, China
| | - Yi Li
- College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China; (G.Y.)
| | - Songtao He
- Guizhou Phosphating Green Environmental Protection Industry Co., Ltd., Guiyang 551100, China
| | - Qibin Liu
- College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China; (G.Y.)
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Chen Q, Sun S, Wang Y, Zhang Q, Zhu L, Liu Y. In-situ remediation of phosphogypsum in a cement-free pathway: Utilization of ground granulated blast furnace slag and NaOH pretreatment. CHEMOSPHERE 2023; 313:137412. [PMID: 36455381 DOI: 10.1016/j.chemosphere.2022.137412] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
In-situ remediating phosphogypsum (PG) for cemented paste backfill (CPB) in the contaminated site is economic management for promoting sustainable developments in the phosphate industry. This study concerns the combined use of NaOH pretreatment and ground-granulated blast furnace slag (GGBFS) additives to promote the solidification/stabilization of PG with a lower carbon footprint pathway. According to physico-chemical analyses, the NaOH pretreatment effectively removed approximately 95% of F within the PG, which may originally be present as sparingly soluble fluorides or coexisting with silicates. The micro mineralogical characterization illustrates that the pretreatment can accelerate the early age hydration, with more hydration products observed, including calcium silicate hydrates and ettringite, effective F and P retention candidates. Whereas the incorporation of GGBFS plays an essential role in promoting the generation of additional cement hydrates at the following stages. The macro mechanical performance analysis indicates that the mixtures of pretreated-PG-OPC-GGBFS exhibit an excellent mechanical performance satisfying the design criteria. Subsequent elemental mapping and toxicity characteristic leaching procedures demonstrate that this combined approach has a competitive F and P immobilization ability compared to the typical OPC binder and individual GGBFS addition. The newly formed phases effectively controlled the concentration of F and P through adsorption, incorporation, or encapsulation. Objectively, the proposed methodology can be a promising candidate pathway for extrapolating the in-situ immobilization of PG. This study opens up new perspectives for synergetically recycling PG and GGBFS in a profitable and low carbon footprint way.
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Affiliation(s)
- Qiusong Chen
- School of Resources and Safety Engineering, Central South University, Lushan South Road 932, 410083, Hunan, China; Sinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan, 243000, China
| | - Shiyuan Sun
- School of Resources and Safety Engineering, Central South University, Lushan South Road 932, 410083, Hunan, China
| | - Yunmin Wang
- School of Resources and Safety Engineering, Central South University, Lushan South Road 932, 410083, Hunan, China
| | - Qinli Zhang
- School of Resources and Safety Engineering, Central South University, Lushan South Road 932, 410083, Hunan, China
| | - Liming Zhu
- School of Resources and Safety Engineering, Central South University, Lushan South Road 932, 410083, Hunan, China
| | - Yikai Liu
- Department of Geosciences and CIRCe Centre, University of Padua, Via G. Gradenigo 6, 35129, Padua, Italy.
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Eliwa AA, Mubark AE, Abdelfattah NA, El Gawad EA. Maximizing the exploitation of phosphogypsum wastes using soaking technique with citric acid, recovering rare-earth and residual phosphate contents. JOURNAL OF CENTRAL SOUTH UNIVERSITY 2022; 29:3896-3911. [DOI: 10.1007/s11771-022-5209-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 09/04/2022] [Indexed: 09/02/2023]
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Zhang Y, Tao Z, Wu L, Zhang Z, Zhao Z. Strength Prediction of Ball-Milling-Modified Phosphorus Building Gypsum Based on NSGM (1,4) Model. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7988. [PMID: 36431473 PMCID: PMC9696628 DOI: 10.3390/ma15227988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/06/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
Phosphogypsum is an industrial byproduct from the wet preparation of phosphoric acid. Phosphorus building gypsum can be obtained from phosphogypsum after high-thermal dehydration. This study aimed to analyze the influence of ball milling with different parameters on the strength of phosphorus building gypsum. In this paper, the absolute dry flexural strength and the absolute dry compressive strength of phosphorus building gypsum were compared under different mass ratios of material to ball, ball-milling speed, and ball-milling time, and the NSGM (1,4) model was applied to model and predict the strength of phosphorus building gypsum modified by ball milling. According to the research results, under the same mass ratio of material to ball and ball-milling speed, the absolute dry flexural strength and absolute dry compressive strength of phosphorus building gypsum firstly increased and then decreased with the increase in milling time. The NSGM (1,4) model established in this paper could effectively simulate and predict the absolute dry flexural strength and the absolute dry compressive strength of the ball-milling-modified phosphorus building gypsum; the average relative simulation errors were 12.38% and 13.77%, and the average relative prediction errors were 6.30% and 12.47%.
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Affiliation(s)
- Yi Zhang
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China
| | - Zhong Tao
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Earthquake Engineering Research Institute, Kunming 650500, China
| | - Lei Wu
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China
| | - Zhiqi Zhang
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China
| | - Zhiman Zhao
- Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China
- Yunnan Ningchuang Environmental Technology Co., Ltd., Anning 650300, China
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Wu F, Liu S, Qu G, Chen B, Zhao C, Liu L, Li J, Ren Y. Highly targeted solidification behavior of hazardous components in phosphogypsum. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2021.100227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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11
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Wei Z, Deng Z. Research hotspots and trends of comprehensive utilization of phosphogypsum: Bibliometric analysis. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 242:106778. [PMID: 34847525 DOI: 10.1016/j.jenvrad.2021.106778] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 11/18/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
Phosphogypsum is a by-product of the phosphate fertilizer industry. It is generally treated by stacking, which not only causes environmental pollution, but also wastes resources. Therefore, the harmless, comprehensive, and high-value utilization of phosphogypsum has attracted more and more scholars around the world. From the perspective of bibliometrics, this paper systematically and comprehensively describes the research progress, trends and hot spots of phosphogypsum resource utilization. This article is based on a scientific network database, and a total of 1067 articles from 1985 to 2020 were collected. Then, use VOSViewer software to perform co-occurrence, co-citation analysis and cluster analysis. The visual analysis results demonstrate that the research on the resource utilization of phosphogypsum shows the characteristics of rapid growth. The active countries are mainly China, Brazil, Spain and the United States. Four of the top 10 active organizations are from China. It systematically expounds the changes in research hotspots in this field at different stages and possible future research hotspots. Including the gradual attention to the preparation of phosphogypsum building materials, phosphogypsum adsorption materials, and radioactive elements in phosphogypsum; the extraction of rare earth elements from phosphogypsum; the use of phosphogypsum to prepare fertilizer or soil improvement. Research shows that phosphogypsum can be reasonably designed, transformed, and used in different fields.However, the radioactivity contained in phosphogypsum should be paid attention to because it has an impact on humans and the environment. We believe that this research provides a comprehensive and systematic overview for future research on phosphogypsum resource utilization.
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Affiliation(s)
- Zhongqi Wei
- College of Mining, Guizhou University, Guiyang, 550025, China.
| | - Zhengbin Deng
- College of Mining, Guizhou University, Guiyang, 550025, China; National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas, Guiyang, 550025, China; Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources, Guiyang, 550025, China.
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12
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Zhao R, Wang B, Theng BKG, Wu P, Liu F, Lee X, Chen M, Sun J. Fabrication and environmental applications of metal-containing solid waste/biochar composites: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 799:149295. [PMID: 34388886 DOI: 10.1016/j.scitotenv.2021.149295] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/17/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
The resource utilization of industrial solid waste has become a hot issue worldwide. Composites of biochar with metal-containing solid wastes (MCSWs) can not only improve the adsorption performance, but also reduce the cost of modification and promote the recycling of waste resources. Thus, the synthesis and applications of biochar composites modified by MCSWs have been attracting increasing attention. However, different MCSWs may result in metal-containing solid waste/biochar composites (MCSW-BCs) with various physicochemical properties and adsorption performance, causing distinct adsorption mechanisms and applications. Although a lot of researches have been carried out, it is still in infancy. In particular, the explanation on the adsorption mechanisms and influencing factors of pollutant onto MCSW-BCs are not comprehensive and clear enough. Therefore, a systematic review on fabrication and potential environmental applications of different MCSW-BCs is highly needed. Here we summarize the recent advances on the utilization of typical metal-containing solid wastes, preparation of MCSW-BCs, adsorption mechanisms and influencing factors of pollutants by MCSW-BCs as well as their environmental applications. Finally, comments and perspectives for future studies are proposed.
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Affiliation(s)
- Ruohan Zhao
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China
| | - Bing Wang
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China.
| | - Benny K G Theng
- Manaaki Whenua-Landcare Research, Palmerston North, New Zealand
| | - Pan Wu
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China
| | - Fang Liu
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China
| | - Xinqing Lee
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Miao Chen
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China
| | - Jing Sun
- College of Resources and Environment Engineering, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou 550025, China
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13
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Cao Y, Cui Y, Yu X, Li T, Chang IS, Wu J. Bibliometric analysis of phosphogypsum research from 1990 to 2020 based on literatures and patents. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:66845-66857. [PMID: 34235698 DOI: 10.1007/s11356-021-15237-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
The demand together with the urgency of phosphogypsum (PG) treatment will pose significant challenges for many countries. This research aims to explore the research progress of PG, including basic status, cooperation situation, research fields, and development trends, based on the Web of Science database through bibliometric analysis of publications (articles and patents) from 1990 to 2020. The results show that academic research on PG originated early, but the number of patents grew quickly. China is a global leader in terms of the number of publications and plays a significant role in international cooperation. The knowledge of PG has remained concentrated in the fields of natural radioactivity, cement paste backfilling, soil, crystal morphology, and synthetic gas. However, academic hotspots focus on the microstructure of chemical processes and various environmental impacts; patents and hot technologies are based on the production of refractory materials, ceramics, surface materials, cement mortar, and composite materials. The academic frontiers of PG will be centered on exploiting the methods of recovering rare earth elements from PG, the conditions of ion solidification/stabilization in PG, the impact of reaction conditions on product quality, and the reaction mechanism at the micro-level. The frontiers of patents need to focus on the improvement of manufacturing equipment, new wall materials, and chemically modified polymer materials. Envisaging the number of articles and patents to be published in the future, architectural research has a large room for improvement. This paper conducts an in-depth analysis of PG and provides information on the technological development prospects and opportunities, which is helpful for researchers engaged in PG management.
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Affiliation(s)
- Yunmeng Cao
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, People's Republic of China
| | - Yue Cui
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, People's Republic of China
| | - Xiaokun Yu
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, People's Republic of China
| | - Tong Li
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, People's Republic of China
| | - I-Shin Chang
- School of Ecology and Environment, Inner Mongolia University, Hohhot, Inner Mongolia, 010021, People's Republic of China.
| | - Jing Wu
- College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, People's Republic of China.
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14
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Zhong D, Wang J, Hou G, Wang L, Wu Q, Lu B. Performance and Nanostructure Simulation of Phosphogypsum Modified by Sodium Carbonate and Alum. MATERIALS 2021; 14:ma14195830. [PMID: 34640227 PMCID: PMC8510265 DOI: 10.3390/ma14195830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022]
Abstract
This paper presents a new modification of the nanostructure of CaSO4·2H2O crystals containing nanopores. This nanoporous structure was achieved in phosphogypsum samples that were modified by sodium carbonate and alum. The effects of sodium carbonate and alum on the properties of phosphogypsum were studied. X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods were used to explore the micro-mechanism of the composite system. Subsequently, molecular dynamics simulations were used to study the nanopore structures of the modified CaSO4·2H2O. The results show that the addition of sodium carbonate and alum reduced the absolute dry density by 23.1% compared with the original phosphogypsum sample, with a bending strength of 2.1 MPa and compressive strength of 7.5 MPa. In addition, new hydration products, sodium sulfate and sodium aluminum sulfate, were formed in the sample doped with sodium carbonate and alum. A new nanostructure of CaSO4·2H2O crystal containing nanopores was formed. Molecular simulations show that the hydration products were responsible for the surface nanopore formation, which was the main factor leading to an increase in mechanical strength. The presented nanopore structure yields lightweight and high strength properties in the modified phosphogypsum.
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Affiliation(s)
- Dongqing Zhong
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; (D.Z.); (G.H.); (L.W.); (Q.W.)
| | | | - Guihua Hou
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; (D.Z.); (G.H.); (L.W.); (Q.W.)
| | - Luming Wang
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; (D.Z.); (G.H.); (L.W.); (Q.W.)
| | - Qian Wu
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; (D.Z.); (G.H.); (L.W.); (Q.W.)
| | - Bao Lu
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; (D.Z.); (G.H.); (L.W.); (Q.W.)
- Correspondence:
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15
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Rare Earths’ Recovery from Phosphogypsum: An Overview on Direct and Indirect Leaching Techniques. MINERALS 2021. [DOI: 10.3390/min11101051] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The need for rare earths elements (REEs) in high tech electrical and electronic based materials are vital. In the global economy, deposits of natural REEs are limited except for countries such as China, which has prompted current attempts to seek alternative resources of REEs. This increased the dependence on major secondary rare earth-bearing sources such as scrap alloy, battery waste, spent catalysts, fly ash, spent magnets, waste light-emitting diodes (LEDs), and phosphogypsum (PG) for a substantial recovery of REEs for use. Recycling of REEs from these alternative waste sources through hydrometallurgical processes is becoming a sustainable and viable approach due to the low energy consumption, low waste generation, few emissions, environmentally friendliness, and economically feasibility. Industrial wastes such as the PG generated from the production of phosphoric acid is a potential secondary resource of REEs that contains a total REE concentration of over 2000 mg/kg depending upon the phosphate ore from which it is generated. Due to trace concentration of REEs in the PG (normally < 0.1% wt.) and their tiny and complex occurrence as mineral phases the recovery process of REE from PG would be highly challenging in both technology and economy. Various physicochemical pre-treatments approaches have been used up to date to up-concentrate REEs from PG prior to their extraction. Methods such as carbonation, roasting, microwave heating, grinding or recrystallization have been widely used for this purpose. This present paper reviews recent literature on various techniques that are currently employed to up-concentrate REs from PG to provide preliminary insight into further critical raw materials recovery. In addition, the advantages and disadvantages of the different strategies are discussed as avenues for realization of REE recovery from PG at a larger scale. In all the different approaches, recrystallization of PG appears to show promising advantages due to both high REE recovery as well as the pure PG phase that can be obtained.
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16
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Liu H, Zhang J, Li B, Zhou N, Li D, Zhang L, Xiao X. Long term leaching behavior of arsenic from cemented paste backfill made of construction and demolition waste: Experimental and numerical simulation studies. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125813. [PMID: 33862486 DOI: 10.1016/j.jhazmat.2021.125813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
The arsenic long-term leaching behavior of the cemented paste backfill obtained from the construction and demolition waste (CPB-CDW) is captured, which can be utilized in the potential engineering application. Laboratory studies were conducted on samples obtained from a mining site and the test results were imported into a numerical simulation model. It was found that the Elovich equation can describe well the As leaching behavior. Initially, the As concentrations decreased in the roadway in the mine and then increased along the roadway and attained a maximum concentration (8.149 × 10-3 mg/L) at the lower segment. When the groundwater was in the static mode, the As concentration increased dramatically followed by a gradual increase. Eventually, the concentration decreased gradually. For the dynamic condition, the As tended to move in a cluster form and the associated leaching and mass transfer process of As in the CPB-CDW were similar to those observed when the groundwater was in a static condition. However, the difference in the distribution of the amount of As in the leachate fluctuated continuously and the overall trend was to approach a steady state. As such, the time frame of such a mass transfer in the mobilized water is reduced significantly.
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Affiliation(s)
- Hengfeng Liu
- State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China; Key Laboratory of Coal Resources and Mineral Resources, Jiangsu Design Institute of Geology for Mineral Resources, China National Administration of Coal Geology, Xuzhou 221116, China
| | - Jixiong Zhang
- State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China.
| | - Baiyi Li
- State key laboratory for geomechanics & deep underground engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Nan Zhou
- State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China
| | - Danqi Li
- WA School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Kalgoorlie, WA 6430, Australia.
| | - Luobin Zhang
- State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China
| | - Xin Xiao
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
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17
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Sun L, Zhao Z, Yang X, Sun Y, Li Q, Luo C, Zhao Q. Thermochemical decomposition of phosphogypsum with Fe-P slag via a solid-state reaction. Chin J Chem Eng 2021. [DOI: 10.1016/j.cjche.2021.06.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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Kuzmanović P, Todorović N, Mrđa D, Forkapić S, Petrović LF, Miljević B, Hansman J, Knežević J. The possibility of the phosphogypsum use in the production of brick: Radiological and structural characterization. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125343. [PMID: 33621775 DOI: 10.1016/j.jhazmat.2021.125343] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
In this paper, phosphogypsum (PG) with the content of 226Ra of about 500 Bq kg-1 was used as a clay additive in mass ratios of (0-40) % and its influence on the radiological and mineralogical characteristics of the obtained brick samples was monitored. After sintering the samples at 1000 ℃, the formation of the mineral phase gehlenite was observed, and its share increased with the share of PG in the samples. The Monte Carlo method was used to determine the gamma dose rates, and consequently annual effective dose, for a standard room, with dimensions 4 × 5 × 2.8 m, whose walls were built of brick with PG. The obtained values were in the range (0.22-0.35) mSv y-1. In addition, the active device RAD7 was used to determine the radon surface exhalation rates from the samples, which were found to be in the range (63-150) mBq m-2 h-1. The estimated indoor radon concentrations were found to be drastically lower than 100 Bq m-3, leading to low radon inhalation doses. However, estimated annual effective doses from external gamma exposure were found not to be insignificant.
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Affiliation(s)
- Predrag Kuzmanović
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia; Academy of Professional Studies Šabac, Department of Medical and Business-Technological Studies, Laboratory for Physics, Hajduk Veljkova 10, 15000 Šabac, Serbia.
| | - Nataša Todorović
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
| | - Dušan Mrđa
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
| | - Sofija Forkapić
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
| | - Leposava Filipović Petrović
- Academy of Professional Studies Šabac, Department of Medical and Business-Technological Studies, Laboratory for Physics, Hajduk Veljkova 10, 15000 Šabac, Serbia
| | - Bojan Miljević
- Faculty of Technology, Department of Materials Engineering, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia
| | - Jan Hansman
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
| | - Jovana Knežević
- Faculty of Sciences, Department of Physics, University of Novi Sad, Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
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19
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Low-Carbon Sustainable Composites from Waste Phosphogypsum and Their Environmental Impacts. CRYSTALS 2021. [DOI: 10.3390/cryst11070719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Phosphogypsum (PG) is an industrial waste from the production of phosphoric acid and phosphate fertilizer. Disposal and landfill of PG pose significant environmental problems due to its hazardous components. Although many researchers have explored the possibility of PG recycling, challenges still exist before it can be high-effectively reused. In particular, a great deal of recent attention has been attracted to explore using PG as raw material to manufacture sustainable composites. The impurities movement, recycling efficiency, and environmental impacts have to be further investigated. This review article summarized the state of the art of the purification process, application areas, and the environmental impacts of PG waste. The main challenges and potential application approaches were discussed. This article is focused on reviewing the details of the PG reusing which benefits the readers on learning the knowledge from previous efforts. The main challenges of reusing PG were discussed from the chemical, physical, and materials perspectives.
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20
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Ben Chabchoubi I, Bouguerra S, Ksibi M, Hentati O. Health risk assessment of heavy metals exposure via consumption of crops grown in phosphogypsum-contaminated soils. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:1953-1981. [PMID: 33216311 DOI: 10.1007/s10653-020-00777-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
The management of phosphogypsum (PG) heap, located south of the Sfax city in Tunisia, has been going on for decades. But dumping this solid waste still poses environmental problems. Even though valorized as amendment to agriculture soils, the sanitary impact of this practice is not seriously considered. To assess the risk of the transference of contaminants from PG to agricultural soil-plants food chain, a wild plant species Salicornia arabica grown in PG-contaminated field and tomato (Lycopersicon esculentum) and oat (Avena sativa) grown in laboratory using different rates (10, 20 and 30%) of PG amendment, were tested. The cadmium, lead, chromium, nickel, copper and zinc concentrations in soils and plants were determined by atomic absorption spectrometry and by inductively coupled plasma-mass spectrometry, respectively. Measurements showed that Ni, Cu and Pb levels in the amended soils were below international standards except for Cd and Cr which exceeded Chinese, FAO/WHO and European allowable standard limits. Gathered results showed that the more the PG rate increases, the more the bioconcentration factors of heavy metals increased in plants, particularly in the roots. This is a prospective study assuming direct or indirect exposure scenario of different human cohorts by consuming varied common food stuffs. The Human Exposure to Soil Pollutants evaluation and United State Environment Protection Agency models were adopted for the hazard quotient calculation to assess the acceptability of sanitary risk related to each metal. The direct and indirect health risk assessments varied in the decreasing order: children, adolescents and then adults. Therefore, the PG amendment must not exceed the rate of 10%.
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Affiliation(s)
- Imen Ben Chabchoubi
- Institut Supérieur de Biotechnologie de Monastir, Université de Monastir, Rue Taher Haddad, 5000, Monastir, Tunisia
- Laboratoire Génie de l'Environnement et Ecotechnologie (GEET), Ecole Nationale d'Ingénieurs de Sfax (ENIS), Route de Soukra, Km 3,5, B.P. 1173, 3038, Sfax, Tunisia
| | - Sirine Bouguerra
- Laboratoire Génie de l'Environnement et Ecotechnologie (GEET), Ecole Nationale d'Ingénieurs de Sfax (ENIS), Route de Soukra, Km 3,5, B.P. 1173, 3038, Sfax, Tunisia
- GreenUPorto - Sustainable Agrifood Production Research Center, Department of Biology, Faculty of Sciences, University of Porto, Rua Campo Alegre, s/n, 4169-007, Porto, Portugal
| | - Mohamed Ksibi
- Laboratoire Génie de l'Environnement et Ecotechnologie (GEET), Ecole Nationale d'Ingénieurs de Sfax (ENIS), Route de Soukra, Km 3,5, B.P. 1173, 3038, Sfax, Tunisia
- Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Route de Soukra, Km 4,5, B.P. 1175, 3038, Sfax, Tunisia
| | - Olfa Hentati
- Laboratoire Génie de l'Environnement et Ecotechnologie (GEET), Ecole Nationale d'Ingénieurs de Sfax (ENIS), Route de Soukra, Km 3,5, B.P. 1173, 3038, Sfax, Tunisia.
- Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Route de Soukra, Km 4,5, B.P. 1175, 3038, Sfax, Tunisia.
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21
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Nedelciu CE, Ragnarsdottir KV, Schlyter P, Stjernquist I. Global phosphorus supply chain dynamics: Assessing regional impact to 2050. GLOBAL FOOD SECURITY-AGRICULTURE POLICY ECONOMICS AND ENVIRONMENT 2020; 26:100426. [PMID: 32953430 PMCID: PMC7490587 DOI: 10.1016/j.gfs.2020.100426] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 11/19/2022]
Abstract
Phosphorus (P) availability is essential for global food security. A system dynamics model running from 1961 to 2050 was built for this study, linking global P supply to social, economic and environmental dynamics at regional level. Simulation results show that phosphate rock (PR) production needs to double by 2050 compared to present levels, in order to match regional P requirements. South Asia, Latin America and the Caribbean, and Sub-Saharan Africa are regions highly dependent on phosphate imports, yet it is here that most of the population growth and future P requirement will occur. Climate impact, eutrophication and phosphogypsum production are some of the main negative environmental dynamics that are becoming increasingly challenging in the coming decades.
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Affiliation(s)
- C E Nedelciu
- Department of Physical Geography, Stockholm University, Sweden
- Faculty of Earth Sciences, University of Iceland, Iceland
| | | | - P Schlyter
- Department of Spatial Planning, Blekinge Institute for Technology, Sweden
| | - I Stjernquist
- Department of Physical Geography, Stockholm University, Sweden
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22
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Abstract
The aim of the research is a comprehensive evaluation of concrete using the EIPI method. In the evaluation the compressive strength of concrete and its durability properties represented by sorptivity and air permeability are taken into account. Since waste copper slag with increased natural radioactivity is used in the assessed concrete, additional evaluation is carried out taking into account the influence of natural radioactivity within the performance index. Additionally, the reference concrete, which is made without the use of waste copper slag, is evaluated for comparative purposes. In order to make the evaluation as comprehensive as possible, the concrete made with the use of three types of cement is subjected to CEM I, CEM II and CEM III assessments. If natural radioactivity is not taken into account in the evaluation, the best result of the most favourable value of Gross Ecological and Performance Indicator (GEPI) is obtained by the concrete made with waste copper slag, and if radioactivity is considered, the most favourable value of GEPI is obtained with concrete without addition of the waste. The results show that in both approaches the best result is achieved by concrete with CEM III cement. It follows from the above that although natural radioactivity has a significant impact on the EIPI evaluation result, the decisive factor is still the type of cement.
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23
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Shu J, Chen M, Wu H, Li B, Wang B, Li B, Liu R, Liu Z. An innovative method for synergistic stabilization/solidification of Mn 2+, NH 4+-N, PO 43- and F - in electrolytic manganese residue and phosphogypsum. JOURNAL OF HAZARDOUS MATERIALS 2019; 376:212-222. [PMID: 31129319 DOI: 10.1016/j.jhazmat.2019.05.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/02/2019] [Accepted: 05/11/2019] [Indexed: 06/09/2023]
Abstract
Electrolytic manganese residue (EMR) contains large quantities of manganese (Mn2+) and ammonia nitrogen (NH4+-N). Phosphogypsum (PG) contains plenty of phosphate (PO43-), fluorine (F-) and some heavy metals. Separate storage of EMR and PG could seriously damage the ecological environment. In this study, synergistic stabilization/solidification (S/S) of EMR and PG was studied. The effects of EMR:PG mass ratio, S/S pH, solid-liquid ratio and temperature on the concentrations of NH4+-N, PO43-, Mn2+ and F- in the leaching solution, and the characteristics of EMR and PG were studied. Meanwhile, the synergistic S/S mechanisms of EMR and PG, and leaching test were investigated. The results showed that the concentrations of F-, PO43-, NH4+-N and Mn2+ in the leaching solution were 4.5 mg/L, 13.6 mg/L, 55.5 mg/L and 0.8 mg/L, respectively, when the mass ratio of EMR to PG was 1:2 and the pH was 9.0 adjusted by MgO after 20 days S/S. Manganese was mainly solidified as Mn3(PO4)2·7H2O and Mn(OH)2, and ammonia nitrogen was mainly stabilized as struvite; fluorine was mainly stabilized as (Mn, Ca, Mg)F2, and phosphate was mainly solidified as (Mn, Ca, Mg)3(PO4)2 and (Mn, Ca, Mg)HPO4. The leaching test results showed that PO43- and NH4+-N were reduced to 13.6 mg/L and 55.5 mg/L, respectively, and the concentrations of all the measured heavy metals and F- were within the permitted level for the GB8978-1996 after 20 days S/S.
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Affiliation(s)
- Jiancheng Shu
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China.
| | - Mengjun Chen
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China
| | - Haiping Wu
- Sichuan Jiuzhou Technician College, Jiusheng Road, Mianyang, 621099, China
| | - Bobo Li
- College of Mining, Guizhou University, Guiyang, 550025, China
| | - Bin Wang
- Key Laboratory of Solid Waste Treatment and Resource Recycle (SWUST), Ministry of Education, Southwest University of Science and Technology, 59 Qinglong Road, Mianyang, 621010, China
| | - Bing Li
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China
| | - Renlong Liu
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China
| | - Zuohua Liu
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China
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24
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Mi Y, Chen D, Wang A. Effects of phosphorus impurities on the preparation of α-calcium sulfate hemihydrate from waste phosphogypsum with the salt solution method under atmospheric pressure. CrystEngComm 2019. [DOI: 10.1039/c9ce00140a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Impurity is an important factor that determines the crystallization process of α-calcium sulfate hemihydrate (α-CSH), but the effects of phosphorus impurities in waste phosphogypsum on the α-CSH prepared using the salt solution method are still not well known.
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Affiliation(s)
- Yang Mi
- School of Materials Science and Engineering
- Southwest University of Science and Technology
- Mianyang 621010
- China
| | - Deyu Chen
- School of Materials Science and Engineering
- Southwest University of Science and Technology
- Mianyang 621010
- China
| | - Aiwen Wang
- School of Materials Science and Engineering
- Southwest University of Science and Technology
- Mianyang 621010
- China
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25
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Al Mugahed M, Bentayeb F. RADON EXHALATION FROM BUILDING MATERIALS USED IN YEMEN. RADIATION PROTECTION DOSIMETRY 2018; 182:405-412. [PMID: 29767765 DOI: 10.1093/rpd/ncy081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
The present article seeks to determine the annual effective doses of 222Rn exposure, effective radium content and radon exhalation rates in some building materials from the local market of Ibb province, Yemen. A total of 33 samples of building materials were collected from the target area. The radon exhalation rate and effective radium content in these samples were measured using solid-state nuclear track detector, which has become an important tool in every investigation of the radon levels in the surrounding environment. Surface exhalation rate has been found to vary from 178.90 to 1267.6 mBq m-2 h-1, whereas mass exhalation rate has been found to vary from 5.51 to 33.25 mBq kg-1 h-1. All the values of effective radium content in all samples under test were found to be quite lower than the permissible value of 370 Bq kg-1 recommended by Organization for Economic Cooperation and Development. Annual effective doses have also been estimated.
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Affiliation(s)
- Murad Al Mugahed
- Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco
| | - Farida Bentayeb
- Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco
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26
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Schaefer CO, Cheriaf M, Rocha JC. Production of Synthetic Phosphoanhydrite and Its Use as a Binder in Self-Leveling Underlayments (SLU). MATERIALS 2017; 10:ma10080958. [PMID: 28817091 PMCID: PMC5578324 DOI: 10.3390/ma10080958] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 06/30/2017] [Accepted: 08/08/2017] [Indexed: 11/16/2022]
Abstract
An experimental study was conducted to investigate the potential use of phosphogypsum (PG) to produce self-leveling underlayments. The study was designed in two stages. Initially a phosphoanhydrite (PA) was produced by heating phosphogypsum at temperatures of 350 °C, 450 °C, 550 °C, and 650 °C. Two periods of heating were applied (2 and 4 h). The formation of anhydrite was determined by thermogravimetric analysis (DTA-TG) and confirmed by X-ray diffraction (XRD). The results show that anhydrite II was obtained at temperatures above 450 °C, and at higher calcination temperatures the PA solubility was lower. In the second stage of this research, the PA was used in self-leveling underlayments as the main binder in the ternary system comprised of calcium sulfate, calcium aluminate cement, and Portland cement. Self-leveling mortar screeds produced using PA (550 °C/4 h) and PA (650 °C/4 h) showed the best performance in terms of mechanical strength and no degradation was observed after immersion and immersion-drying tests. The formation of ettringite, identified by scanning electron microscopy (SEM), may have contributed to these results. Morphological changes were studied using the scanning electron microscopy (SEM) technique.
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Affiliation(s)
- Cecília Ogliari Schaefer
- Post-Graduate Program in Civil Engineering, Federal University of Santa Catarina, CEP 88040-900 Florianópolis, SC, Brazil.
| | - Malik Cheriaf
- Department of Civil Engineering, Federal University of Santa Catarina, CEP 88040-900 Florianópolis, SC, Brazil.
| | - Janaíde Cavalcante Rocha
- Department of Civil Engineering, Federal University of Santa Catarina, CEP 88040-900 Florianópolis, SC, Brazil.
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