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Wang P, Li J, Hu Y, Cheng H. Environmental performance of unfired bricks produced from co-disposal of mine tailings and municipal solid waste incineration fly ash based on comprehensive leaching tests. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 347:123795. [PMID: 38490524 DOI: 10.1016/j.envpol.2024.123795] [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: 12/17/2023] [Revised: 02/23/2024] [Accepted: 03/13/2024] [Indexed: 03/17/2024]
Abstract
The potential leaching of heavy metals is a crucial concern for construction materials produced from solidification/stabilization (S/S) treatment of wastes. This study comprehensively evaluated the leaching characteristics of heavy metals from the unfired bricks produced from co-disposal of Pb-Zn mine tailings and municipal solid waste incineration fly ash using batch, sequential, and semi-dynamic leaching tests. The results show that S/S treatment drastically reduced the leachability of heavy metals from the unfired bricks through lowering their distribution in the acid-soluble fraction. The effective diffusion coefficients of heavy metals within unfired bricks were all below 1.55 × 10-13 cm2/s, which is indicative of low mobility in the environment. The release of heavy metals from the unfired bricks was primarily governed by diffusion and dissolution. Slaking treatment of fly ash significantly reduced the leaching of heavy metals from the unfired bricks due to their improved structural integrity and compactness, which minimizes the surface area in the solid matrix accessible by the leaching medium. The leachability indices of heavy metals within the unfired bricks ranged from 13.12 to 18.10, suggesting that they are suitable for "controlled utilization" in specific scenarios. Compared to untreated mine tailings, converting them into unfired bricks could reduce the releases of heavy metals by several to hundreds of folds. These findings demonstrate that S/S can be an effective and sustainable strategy for co-disposal of mining tailings and incineration fly ash to produce construction materials with sound long-term environmental performance.
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Affiliation(s)
- Ping Wang
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China; MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Jiangshan Li
- State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Yuanan Hu
- MOE Laboratory of Groundwater Circulation and Evolution, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Hefa Cheng
- MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
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2
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Tang L, He Z, Chen K, Wang X, Xiao Y, Yu Z, Xiao H. Study of microscopic properties and heavy metal solidification mechanism of electrolytic manganese residue-based cementitious materials. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:105056-105071. [PMID: 37726634 DOI: 10.1007/s11356-023-29772-3] [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: 11/18/2022] [Accepted: 09/04/2023] [Indexed: 09/21/2023]
Abstract
Electrolytic manganese residue (EMR) is a solid waste that contains a significant amount of soluble manganese and ammonia nitrogen, which can pose risks to human health if improperly disposed of. This study aimed to prepare cementitious materials containing abundant ettringite crystals by mixing EMR with various proportions of granulated blast furnace slag (GBFS) and alkaline activators (CaO, Ca(OH)2, clinker, NaOH). The resulting cementitious material not only utilized a substantial amount of EMR but also exhibited comparable strength to ordinary Portland cement. The optimal ratios were determined through mechanical testing. Additionally, the leaching toxicity of cementitious materials was assessed using ICP-MS (inductively coupled plasma mass spectrometer) tests. The microscopic properties, hydration, and mechanism of heavy metal solidification in the cementitious materials were evaluated using XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy-dispersive spectrometer), FTIR (Fourier transform infrared spectroscopy), and TG (thermogravimetric) techniques. The results showed that the optimal ratio for the cementitious materials was 60% EMR, 36% GBFS, and 4% Ca(OH)2. The hardened mortar exhibited compressive strengths of 34.43 MPa, 41.3 MPa, and 50.89 MPa at 3 days, 7 days, and 28 days, respectively, with an EMR utilization rate of 60%. The hydration products of EMR-based cementitious materials were C-(A)-S-H, AFt, and ferromanganese compounds, which contribute to the mechanical strength. The Mn2+ and NH4+-N contents of raw EMR were 1220 and 149 mg/L, respectively. Nonetheless, the leaching of Mn2+ and NH4+-N in the alkali-EMR-GBFS system was significantly below the limits set by the Chinese emission standard GB8978-1996. Within this system, C-(A)-S-H and AFt could physically adsorb and displace heavy metals, Ca6Mn2(SO4)2(SO3)2(OH)12·24H2O could replace Al ions with Mn ions, and ferromanganese compounds Fe2Mn(PO4)2(OH)2·(H2O)8 and MnFe2O4 could chemically precipitate Mn2+.
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Affiliation(s)
- Liang Tang
- School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Zhaoyi He
- College of Traffic and Transportation, Chongqing Jiaotong University, Chongqing, 400074, China.
| | - Kefan Chen
- College of Traffic and Transportation, Chongqing Jiaotong University, Chongqing, 400074, China
- Chongqing Chongjiao Renewable Resources Development Co., Ltd, Chongqing, 400000, China
| | - Xiaoli Wang
- School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Yixun Xiao
- School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Zhou Yu
- School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Haixin Xiao
- School of Civil Engineering, Chongqing Jiaotong University, Chongqing, 400074, China
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Mi R, Zhang Z, Ji W, Liu S, Kai MF, Lin K, Tan Y. Solidification/stabilisation behaviours of Zn 2+ in magnesium potassium phosphate cement: Experiments and density functional theory study. ENVIRONMENTAL RESEARCH 2023; 231:116247. [PMID: 37245576 DOI: 10.1016/j.envres.2023.116247] [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: 02/13/2023] [Revised: 05/16/2023] [Accepted: 05/26/2023] [Indexed: 05/30/2023]
Abstract
The solidification/stabilisation behaviours of Zn2+ in magnesium potassium phosphate cement (MKPC) have not been thoroughly investigated. Herein, a series of experiments and a detailed density functional theory (DFT) study were conducted to investigate the solidification/stabilisation behaviours of Zn2+ in MKPC. The results showed that the compressive strength of MKPC reduced with the addition of Zn2+ because the formation of MgKPO4·6H2O (the main hydration product in MKPC) was delayed with the addition of Zn2+, as discovered by the crystal characteristics, and because Zn2+ exhibited a lower binding energy in MgKPO4·6H2O compared to Mg2+, as revealed by DFT results. Additonally, Zn2+ had little influence on the structure of MgKPO4·6H2O, and Zn2+ existed in MKPC as the formation of Zn2(OH)PO4, which was decomposed in the range of around 190-350 °C. Moreover, there were a lot of well-crystallised tabular hydration products before the addition of Zn2+, but the matrix was comprised of irregular prism crystals after adding Zn2+. Furthermore, the leaching toxicity of Zn2+ of MKPC was much smaller than the requirements of Chinese and European standards.
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Affiliation(s)
- Renjie Mi
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Zhibin Zhang
- College of Civil Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Weiming Ji
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Shichang Liu
- College of Civil Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - M F Kai
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
| | - Kui Lin
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yongshan Tan
- College of Civil Science and Engineering, Yangzhou University, Yangzhou, 225127, China.
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Duan N, Cui K, Zhu C, Jin S. Study on phase evolution and promoting the pozzolanic activity of electrolytic manganese residue during calcination. ENVIRONMENTAL RESEARCH 2023; 227:115774. [PMID: 36966993 DOI: 10.1016/j.envres.2023.115774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/06/2023] [Accepted: 03/23/2023] [Indexed: 05/08/2023]
Abstract
Electrolytic manganese residue (EMR) is a harmful by-product in the electrolytic manganese industry. Calcination is an efficient method for disposing EMR. In this study, thermogravimetric-mass spectrometry (TG-MS) combined with X-ray diffraction (XRD) was used for analysing the thermal reactions and phase transitions during calcination. The pozzolanic activity of calcined EMR was determined by the potential hydraulicity test and strength activity index (SAI) test. The leaching characteristics of Mn were determined by TCLP test and BCR SE method. The results showed that MnSO4 was converted into stable MnO2 during calcination. Meanwhile, Mn-rich bustamite (Ca0.228Mn0.772SiO3) was converted into Ca(Mn, Ca)Si2O6. The gypsum was transformed into anhydrite and then decomposed into CaO and SO2. Additionally, the organic pollutants and ammonia were completely removed following calcination at 700 °C. The leaching concentration of Mn decreased from 819.9 mg L-1 to 339.6 mg L-1 following calcination at 1100 °C. The chemical forms of Mn were transformed from acid-soluble fraction to residual fraction. The pozzolanic activity tests indicated that EMR1100-Gy maintained a complete shape. The compressive strength of EMR1100-PO reached 33.83 MPa. Finally, the leaching concentrations of heavy metals met the standard limits. This study provides a better understanding for the treatment and utilization of EMR.
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Affiliation(s)
- Nan Duan
- School of Mineral Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Kuixin Cui
- School of Mineral Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China.
| | - Chuyu Zhu
- School of Mineral Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Shengming Jin
- School of Mineral Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China.
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Hamdane H, Oumam M, Mhamdi HS, Bouih A, El Ghailassi T, Boulif R, Alami J, Manoun B, Hannache H. Elaboration of geopolymer package derived from uncalcined phosphate sludge and its solidification performance on nuclear grade resins loaded with 134Cs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159313. [PMID: 36228800 DOI: 10.1016/j.scitotenv.2022.159313] [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: 08/02/2022] [Revised: 09/20/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Nuclear-grade Spent Organic Resin (SOR) contains high concentrations of radioactive nuclides and metal contaminants, while phosphate sludge contains high amount of fine clayey particles and CO32-, both posing a major threat to the biosphere. In this study, a novel geopolymer package (GP) was proposed to directly solidify SOR loaded with 134Cs by incorporating uncalcined phosphate sludge (UPS) as feedstocks, activated by NaOH/KOH. The results showed that alkali-mixed reagents-activated GP is more advantageous in terms of chemical stability and mechanical properties than NaOH-activated GP, recording compressive strength values greater than the waste acceptance criteria and OPC. The 28-day compressive strength of solidified packages can exceed 31 MPa at the highest amount of 42 wt% UPS. The addition of NaF powder into the solidified packages generates more hybrid type gels, which are more conducive to partial dissolution and bonding UPS particles, thereby producing stable and stronger GP. Leaching results of solidified GP in presence of up to 13 wt% SORs showed that only 0.15 % of total 134Cs was leached, even under aggressive solutions. Solidification mechanism revealed that activation of UPS-MK blend forms N,K-A-S-H, (N,K,C)-A-S-H/C-S-H gels coexisting with unreacted particles, thereby solidify/stabilize metal contaminants and Cs+ by a synergetic immobilization action of hydration products via substitution and encapsulation. This study provides a promising paradigm for effective solidification of nuclear-grade resins and synergetic harmless treatment of industrial/phosphate mine solid wastes.
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Affiliation(s)
- Hasna Hamdane
- Laboratory of Engineering and Materials, Faculty of Science Ben M'Sick, Hassan II University of Casablanca, B.P.7955 Casablanca, Morocco; National Center of Sciences, Technology and Nuclear Energy, B.P.1382 Rabat, Morocco.
| | - Mina Oumam
- Laboratory of Engineering and Materials, Faculty of Science Ben M'Sick, Hassan II University of Casablanca, B.P.7955 Casablanca, Morocco
| | - Hicham Si Mhamdi
- Laboratory of Applied Geology, Department of Geosciences, Faculty of Sciences and Techniques Errachidia, Moulay Ismail University of Meknes, Morocco
| | - Abderrahim Bouih
- National Center of Sciences, Technology and Nuclear Energy, B.P.1382 Rabat, Morocco
| | - Touria El Ghailassi
- National Center of Sciences, Technology and Nuclear Energy, B.P.1382 Rabat, Morocco
| | - Rachid Boulif
- Chemical and Biochemical Sciences Department, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, 43150 Benguerir, Morocco
| | - Jones Alami
- Materials Science and Nano-Engineering Department, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, 43150 Benguerir, Morocco
| | - Bouchaib Manoun
- Materials Science and Nano-Engineering Department, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, 43150 Benguerir, Morocco; Univ Hassan(1er), Rayonnement-Matière et Instrumentation, S3M, Faculty of science and Technology, 26000, FST, Settat, Morocco
| | - Hassan Hannache
- Laboratory of Engineering and Materials, Faculty of Science Ben M'Sick, Hassan II University of Casablanca, B.P.7955 Casablanca, Morocco; Materials Science and Nano-Engineering Department, Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, 43150 Benguerir, Morocco
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Quan H, Yu HJ, Yang X, Lv DP, Zhu X, Li YC. Long-Term Stabilization/Solidification of Arsenic-Contaminated Sludge by a Blast Furnace Slag-Based Cementitious Material: Functions of CaO and NaCl. ACS OMEGA 2022; 7:32631-32639. [PMID: 36119981 PMCID: PMC9475631 DOI: 10.1021/acsomega.2c04302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Arsenic is a kind of element widely distributed in the environment that may pose a threat to the ecological environment and human health, while effective remediation and sustainable utilization of arsenic-containing sludge is a challenge. Based on stabilization/solidification blast furnace slag-based cementitious materials (BCMs), this study innovatively proposes to improve the arsenic (As) solidification efficiency and long-term stability by using the activation mode of CaO and NaCl. The effects of different factors on the properties of the BCM were measured by unconfined compressive strength (UCS) tests, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The long-term stability and safety of the BCM were verified by leaching toxicity and improved three stage continuous extraction method (BCR) tests. Experimental results show that the addition of CaO provides conditions for the formation of ettringite (AFt), thus promoting the crystal growth of AFt. The addition of NaCl can promote the formation of Cl-AFt and play a good long-term stabilizing role. When the content of the alkali activator is 10% and the modulus is 1.0, the contents of CaO and NaCl are 10 and 1%, respectively. The BCM has the best efficiency in terms of UCS and As solidification. The UCS at 28 days was 5.4 MPa, and the leaching concentration of As was 0.309 mg/L, and the As solidification efficiency was up to 99.9%. In the improved BCR test, the proportions of residual and oxidizable states of arsenic increased by 19.6 and 13.5%, respectively, and the stability of heavy metals improved. These findings show that the BCM has good long-term stability and safety. Overall, this study shows that CaO and NaCl significantly increase the output of AFt and achieve the purpose of efficient and stable solidification of As by the BCM.
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Affiliation(s)
- Hong Quan
- College
of Agriculture and Biological Sciences, Dali University, Dali, Yunnan 671003, China
- Key
Laboratory of Ecological Microbial Remediation Technology of Yunnan
Higher Education Institutes, Dali University, Dali, Yunnan 671003, China
| | - Hui-juan Yu
- College
of Agriculture and Biological Sciences, Dali University, Dali, Yunnan 671003, China
- Key
Laboratory of Ecological Microbial Remediation Technology of Yunnan
Higher Education Institutes, Dali University, Dali, Yunnan 671003, China
| | - Xue Yang
- College
of Agriculture and Biological Sciences, Dali University, Dali, Yunnan 671003, China
- Key
Laboratory of Ecological Microbial Remediation Technology of Yunnan
Higher Education Institutes, Dali University, Dali, Yunnan 671003, China
| | - Dong-peng Lv
- College
of Agriculture and Biological Sciences, Dali University, Dali, Yunnan 671003, China
- Key
Laboratory of Ecological Microbial Remediation Technology of Yunnan
Higher Education Institutes, Dali University, Dali, Yunnan 671003, China
| | - Xing Zhu
- Faculty
of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China
| | - Yuan-cheng Li
- College
of Agriculture and Biological Sciences, Dali University, Dali, Yunnan 671003, China
- Key
Laboratory of Ecological Microbial Remediation Technology of Yunnan
Higher Education Institutes, Dali University, Dali, Yunnan 671003, China
- Faculty
of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, China
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