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Li B, Guo X, Zhang X, Leng S, Ma N, Wu X. A new strategy to stabilize the heavy metals in carbonized MSWI-fly ash using an acid-resistant oligomeric dithiocarbamate chelator. JOURNAL OF HAZARDOUS MATERIALS 2024; 467:133686. [PMID: 38359762 DOI: 10.1016/j.jhazmat.2024.133686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 02/17/2024]
Abstract
Fly ash (FA) derived from municipal solid waste incineration (MSWI) requires safe handling before landfilling due to its extremely high salt content and the risk of leaching heavy metals (HMs) under acidic conditions. Herein, aimed at improving the acid stability of dithiocarbamates, a cost-effective oligomeric dithiocarbamate (ODTC) was developed to stabilize HMs from carbonated MSWI-FA. Spiking of 3.6 wt% ODTC reduced the HM leaching below landfill standards in China, even across the pH range of 2.0-13.0 or 8-week exposure to the natural environment. Stabilization decreased the acid-soluble/exchangeable fractions of Cd, Pb, and Zn from 22.2%, 4.49%, and 21.9% to 0.14%, 0.11%, and 12.2%, respectively, resulting in safe levels for Pb and Cd with risk assessments. Compared to DDTC and SDD, ODTC exhibited higher stability under acidic conditions after chelation with the HMs, minimized the risk of HM leaching, and significantly reduced stabilization costs. In-depth studies proved that the stabilization mechanism involved the ability of ODTC to chelate HMs strongly and form acid-resistant ODTC-HM complexes, agglomeration of the MSWI-FA grains to encapsulate the ODTC-HM complexes, transformations of the HMs from acid-soluble species to stable oxidizable and residual species, and specifically ODTC reducing high-valent Pb to more stable Pb(II) species.
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Affiliation(s)
- Bojun Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xuejun Guo
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Xiangyuan Zhang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Siwen Leng
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Na Ma
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xiaoqiong Wu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
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2
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Zhao S, Zhang S, Liang X, Li J, Liu C, Ji F, Sun Z. Transformation and environmental chemical characteristics of hazardous trace elements in an 800 t/d waste incineration thermal power plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170693. [PMID: 38325472 DOI: 10.1016/j.scitotenv.2024.170693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/17/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
The hazardous trace elements (HTEs) emitted during the municipal solid waste incineration (MSWI) process have been widely concerned. In this work, the bottom ash (BA), heat recovery boiler ash (HA), and ash after desulfurization (SA) were collected to explore the occurrence forms of HTEs in the three types of ash and their relationship with minerals and leaching characteristics. The results show that the volatility of the seven studied HTEs follows the order of Cd, As > Ni, Zn > Pb > Cr, Cu. In the process of BA → HA → SA, the content of Cd, As, Zn, and Pb shows an increasing trend. The seven HTEs are mainly in the forms of chlorides and oxides. There is an obvious relationship between the occurrence forms and simulated existence form of HTEs. SiO2 and CaCO3 are the major mineral components in the three ashes, while SA also contains chlorine-containing compounds which are easily leached out. The risk assessment code and soluble ratio show that HTEs in SA are more leachable than BA and HA, where Cd, Pb and Ni need to be addressed to reduce their impact on soil or water during subsequent landfill treatment of SA.
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Affiliation(s)
- Shilin Zhao
- School of Energy Science and Engineering, Central South University, Changsha 410083, China; Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou 221116, China
| | - Siqi Zhang
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
| | - Xin Liang
- 3rd Construstion Co., Ltd. of China Construction 5th Engineering Bureau, Changsha 410004, China
| | - Jian Li
- Special Equipment Safety Supervision Inspection Institute of Jiangsu Province, Nanjing 210036, China
| | - Cheng Liu
- School of Energy Science and Engineering, Central South University, Changsha 410083, China
| | - Fu Ji
- School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhiqiang Sun
- School of Energy Science and Engineering, Central South University, Changsha 410083, China.
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3
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Zhang M, Wu Y, Li Y, Zhou R, Yu H, Zhu X, Quan H, Li Y. Risk assessment for the long-term stability of fly ash-based cementitious material containing arsenic: Dynamic and semidynamic leaching. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123361. [PMID: 38228264 DOI: 10.1016/j.envpol.2024.123361] [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: 08/28/2023] [Revised: 12/21/2023] [Accepted: 01/13/2024] [Indexed: 01/18/2024]
Abstract
Fly ash from municipal solid waste incineration (MSWIFA) contains leachable heavy metals (HMs), and the environmental risk of contained HMs is an important concern for its safe treatment and disposal. This paper presents a dynamic leaching test of fly ash-based cementitious materials containing arsenic (FCAC) in three particle sizes based on an innovative simulation of two acid rainfall conditions to investigate the long-term stability of FCAC under acid rain conditions. As well as semi-dynamic leaching test by simulating FCAC in three scenarios. Furthermore, the long-term stability risk of FCAC is evaluated using a sequential extraction procedure (SEP) and the potential risk assessment index. Results showed that the Al3+ in the FCAC dissolved and reacted with the OH- in solution to form Al(OH)3 colloids as the leaching time increased. Moreover, the oxidation of sulfide minerals in the slag produced oxidants, such as H2SO4 and Fe2(SO4)3, which further aggravated the oxidative dissolution of sulfides, thereby resulting in an overall decreasing pH value of the leachate. In addition, due to the varying particle sizes of the FCAC, surface area size, and adsorption site changes, the arsenic leaching process showed three stages of leaching characteristics, namely, initial, rapid, and slow release, with a maximum leaching concentration of 2.42 mg/L, the cumulative release of 133.78 mg/kg, and the cumulative release rate of 2.32%. The SEP test revealed that the reduced state of HMs in the raw slag was lowered substantially, and the acid extractable state and residual state of HMs were increased, which was conducive to lessening the risk of FCAC. Overall, the geological polymerization reaction of MSWIFA is a viable and promising solution to stabilize mining and industrial wastes and repurpose the wastes into construction materials.
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Affiliation(s)
- Mingliang Zhang
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Ying Wu
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Yinmei Li
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Rongwu Zhou
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Huijuan Yu
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Xing Zhu
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
| | - Hong Quan
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China
| | - Yuancheng Li
- College of Agriculture and Biological Science, Dali University, Dali, 671003, Yunnan, China; Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali, 671003, Yunnan, China; Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
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Wang J, Wang J, Liu Z, Yan R. Concentration, speciation and risk effects of multiple environmentally sensitive trace elements in respirable fine-grained fly ash. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133387. [PMID: 38198872 DOI: 10.1016/j.jhazmat.2023.133387] [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: 11/21/2023] [Revised: 12/19/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024]
Abstract
Respirable fine-grained fly ash (RFA) is captured very inefficiently by existing air purification devices of power plant, leading to increasing concerns regarding their migration and subsequent interaction with body due to fine particle size and its complex toxic composition. Trace elements of RFA in three groups with five different sizes between 8-13 µm were analyzed in terms of available concentration, speciation and risk effects. The concentration, pollution level and ecological risk level of elements in RFA were related to particle sizes. Chronic non-carcinogenic effect risk (NER) and carcinogenic effect risk (CER) were negatively correlated with particle size. The individual weight of exposed subjects, corresponding trace elements concentration and ingestion rate in RFA were three significant variables influencing CER. NER and CER had a tenfold exaggerated effect when calculated using total element concentration of RFA. In addition to individual differences and exposure conditions, trace element properties, speciation and available concentration were the dominant factor responsible for ecological and environmental effects of trace elements in RFA, following the order As>Ni, Mn>Cr>Pb>Cu>Zn. Results of this work highlight the effects and differences of trace elements in RFA on ecology and health, and provide a basis for further pollution control and human health warning.
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Affiliation(s)
- Jiao Wang
- Environment and Resources College, Shanxi University, No. 92 Wucheng Rd., Taiyuan 030006, China; Shanxi Laboratory for Yellow River, No. 92 Wucheng Rd, Taiyuan 030006, China.
| | - Junxiu Wang
- Environment and Resources College, Shanxi University, No. 92 Wucheng Rd., Taiyuan 030006, China
| | - Zhiyi Liu
- Shanxi Open University, No. 109 Qianfeng North Rd, Taiyuan 030006, China
| | - Ran Yan
- Environment and Resources College, Shanxi University, No. 92 Wucheng Rd., Taiyuan 030006, China
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5
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Wolffers M, Kulik DA, Miron GD, Eggenberger U, Churakov SV. Thermodynamic model of MSWI flue gas cooling path: Effect of flue gas composition on heavy metal binding forms. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2024; 42:273-284. [PMID: 37313852 DOI: 10.1177/0734242x231178213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In the context of circular economy and heavy metal (HM) recovery from municipal solid waste incineration (MSWI) fly ash (FA), detailed knowledge of HM binding forms is required for achieving higher extraction rates. The FA mineralogy is still poorly understood due to its low grain size and low metal concentration. To investigate the HM binding forms, a sophisticated thermodynamic reactive transport model was developed to simulate ash-forming processes. The stability of different binding forms was investigated at different flue gas conditions (varying ratios of HCl, SO2, O2) by simulating the gas cooling path in closed system and dynamic open system, where the gas composition is changing upon cooling due to precipitation of solids. The simulations predict that at flue gas conditions of molar ratio S/Cl < 1, Cu and Zn precipitate as oxides (and Zn silicates) at approximately 650°C. At temperatures <300°C, Zn, Cu, Pb and Cd are predicted to precipitate as easily soluble chlorides. In flue gas with molar ratio S/Cl > 1, the HM precipitate as less soluble sulphates. The results indicate that the less soluble HM fraction in the electrostatic precipitator ash represent oxides and silicates that formed in the boiler section but were transported to the electrostatic precipitator. The model provides insight into the physical-chemical processes controlling the metal accumulation in the flue gas and FA during the cooling of the flue gas. The obtained data serve as valuable basis for improving metal recovery from MSWI FA.
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Affiliation(s)
- Mirjam Wolffers
- Institute of Geological Sciences, University of Bern, Bern, Switzerland
| | - Dmitrii A Kulik
- Laboratory for Waste Management, Paul Scherrer Institute, Villigen, Switzerland
| | - George-Dan Miron
- Laboratory for Waste Management, Paul Scherrer Institute, Villigen, Switzerland
| | - Urs Eggenberger
- Institute of Geological Sciences, University of Bern, Bern, Switzerland
| | - Sergey V Churakov
- Institute of Geological Sciences, University of Bern, Bern, Switzerland
- Laboratory for Waste Management, Paul Scherrer Institute, Villigen, Switzerland
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Ma X, He T, Da Y, Xu Y, Wan Z. Physical properties, chemical composition, and toxicity leaching of incineration fly ash by multistage water washing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:80978-80987. [PMID: 37310603 DOI: 10.1007/s11356-023-28170-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/05/2023] [Indexed: 06/14/2023]
Abstract
Incineration fly ash contains a large amount of chloride, which limits the scope of its resource utilization. Water washing effectively removes chlorides and soluble substances, increasing the ability to dispose of them. The properties of incineration fly ash after multi-level water washing have been studied, providing theoretical guidance for the safe disposal of water-washed ash at all levels. Taking a practical project as an example, this paper analyzed the impact of three-stage countercurrent water washing on the physicochemical properties and toxicity leaching of incineration fly ash with different washing grades by XRD, BET, XRF, SEM, and ICP-MS. The results showed that with the improvement of washing grade, the removal rate of chloride ions was more than 86.96%. However, due to the removal of soluble substances, dioxins enriched from 98 ng-TEQ/kg of raw ash to 359 ng-TEQ/kg of tertiary washed incineration fly ash. Cr, Cu, and Zn also increased from 40.35 mg/L, 356.55 mg/L, and 3290.58 mg/L of raw ash to 136.30 mg/L, 685.75 mg/L, and 5157.88 mg/L, respectively. Pozzolanic activity had increased from 40.56% of the raw ash to 74.12% of the tertiary-washed incineration fly ash. There was no risk of excessive heavy metal leaching, and the dioxin content was lower than the raw ash in the primary washed incineration fly ash. After multi-stage water washing, incineration fly ash accumulated heavy metals, so more attention must be paid to the issue of heavy metal content in the safe disposal process.
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Affiliation(s)
- Xiaodong Ma
- College of Materials Science and Engineering, Xi'an University of Architecture & Technology, Xi'an, 710055, Shaanxi, China.
| | - Tingshu He
- College of Materials Science and Engineering, Xi'an University of Architecture & Technology, Xi'an, 710055, Shaanxi, China
| | - Yongqi Da
- College of Materials Science and Engineering, Xi'an University of Architecture & Technology, Xi'an, 710055, Shaanxi, China
| | - Yongdong Xu
- College of Materials Science and Engineering, Xi'an University of Architecture & Technology, Xi'an, 710055, Shaanxi, China
| | - Zhenmin Wan
- College of Materials Science and Engineering, Xi'an University of Architecture & Technology, Xi'an, 710055, Shaanxi, China
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7
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Li T, Wang B. Effect and mechanism of nano-alumina on early hydration properties and heavy metals solidification/stabilization of alkali-activated MSWI fly ash solidified body. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131327. [PMID: 37027917 DOI: 10.1016/j.jhazmat.2023.131327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/04/2023] [Accepted: 03/29/2023] [Indexed: 06/19/2023]
Abstract
Municipal solid waste incineration (MSWI) fly ash has serious pollution. It needs to be solidification/stabilization (S/S) to sanitary landfill as quickly as possible. In order to achieve the objective, the early hydration properties of alkali-activated MSWI fly ash solidified body were investigated in this paper. Meanwhile, nano-alumina was utilized as an agent to optimize the early performance. Therefore, the mechanical properties, environmental safety, hydration process and mechanisms of heavy metals S/S were explored. The results showed that after adding nano-alumina, the leaching concentration of Pb and Zn in solidified bodies after 3 d curing was significantly reduced by 49.7-63% and 65.8-76.1%, respectively, and the compressive strength was enhanced by 10.2-55.9%. Nano-alumina improved the hydration process, and the predominant hydration products in solidified bodies were C-S-H gels and C-A-S-H gels. Meanwhile, nano-alumina could obviously increase the most stable chemical speciation (residual state) ratio of heavy metals in solidified bodies. Pore structure data showed that, due to the filling effect and pozzolanic effect of nano-alumina, the porosity has been reduced and the ratio of harmless pore structure has been increased. Therefore, it can be concluded that solidified bodies mainly solidify MSWI fly ash by physical adsorption, physical encapsulation and chemical bonding.
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Affiliation(s)
- Tianru Li
- School of Civil Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Baomin Wang
- School of Civil Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
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8
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Spreadbury CJ, Weiksnar KD, Laux S, Townsend TG. Distributions of trace elements within MSWI bottom and combined ash components: Implications for reuse practices. CHEMOSPHERE 2023; 336:139198. [PMID: 37315860 DOI: 10.1016/j.chemosphere.2023.139198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 05/15/2023] [Accepted: 06/11/2023] [Indexed: 06/16/2023]
Abstract
Concentrations of 25 inorganic elements were measured in both bulk ash and individual ash components from residuals at three municipal solid waste incineration (MSWI) facilities in the US (two combined ash (CA) and one bottom ash (BA)). Concentrations were assessed based on particle size and component to understand the contribution from each fraction. The results found that among facilities, the finer size fractions contained elevated concentrations of trace elements of concern (As, Pb, Sb) when compared to the coarse fraction, but concentrations varied among facilities depending on the type of ash and differences in advanced metals recovery processes. This study focused on several constituents of potential concern, As, Ba, Cu, Pb, and Sb, and found that the main components of MSWI ash (glass, ceramic, concrete, and slag) are sources of these elements in the ash streams. For many elements, concentrations were significantly higher in CA bulk and component fractions opposed to BA streams. An acid treatment procedure and scanning electron microscopy/energy-dispersive x-ray spectroscopy analysis revealed that some elements, such as As in concrete, are result of the inherent properties of the component, but other elements, such as Sb, form on the surface during or after incineration and can be removed. Some Pb and Cu concentrations were attributed to inclusions in the glass or slag introduced into the material during the incineration process. Understanding the contributions of each ash component provides critical information for developing strategies to reduce trace element concentrations in ash streams to promote reuse opportunities.
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Affiliation(s)
- Chad J Spreadbury
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL, 32611-6450, USA
| | - Kate D Weiksnar
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL, 32611-6450, USA
| | - Steve Laux
- 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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9
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Chen Z, Zhang P, Brown KG, van der Sloot HA, Meeussen JCL, Garrabrants AC, Delapp RC, Um W, Kosson DS. Evaluating the impact of drying on leaching from a solidified/stabilized waste using a monolithic diffusion model. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 165:27-39. [PMID: 37080015 DOI: 10.1016/j.wasman.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 03/06/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023]
Abstract
The release rates of constituents of potential concern from solidified/stabilized cementitious waste forms are potentially impacted by drying, which, however, is not well understood. This study aimed to identify the impacts of drying on subsequent leaching from Cast Stone as an example of a solidified cementitious waste form. The release fluxes of constituents from monoliths after aging under 100, 68, 40, and 15 % relative humidity for 16, 32, and 48 weeks, respectively, were derived from mass transfer tank leaching tests following EPA Method 1315. A monolithic diffusion model was calibrated based on the leaching test results to simulate the leaching of major and redox-sensitive constituents from monoliths after drying. The reduction in physical retention of constituents (tortuosity-factor) in the unsaturated zone was identified as the primary impact from drying on subsequent leaching. Fluxes of both major (i.e., OH-, Na, K, Ca, Si, and Al) and redox-sensitive constituents (i.e., Tc, Cr, Fe, and S) from monoliths during leaching were well described by the model. The drying-induced reduction of tortuosity-factor and concomitant changes in porewater pH and redox conditions can significantly change the subsequent release fluxes of pH- and redox- sensitive constituents.
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Affiliation(s)
- Zhiliang Chen
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States
| | - Peng Zhang
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States; Shanghai Shaanxi Coal Hi-tech Research Institute Co., Ltd., Shanghai 201613, China
| | - Kevin G Brown
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States
| | - Hans A van der Sloot
- Hans van der Sloot Consultancy, Glenn Millerhof 29, 1628 TS Hoorn, the Netherlands
| | | | - Andrew C Garrabrants
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States
| | - Rossane C Delapp
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States
| | - Wooyong Um
- Pacific Northwest National Lab., Richland, WA, United States; Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - David S Kosson
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN 37235, United States.
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Huang T, Song D, Zhou L, Di Y, Zhang S, Tao H. Synergistic influence of diatomite and MoS 2 nanosheets on the self-alkali-activated cementation of the municipal solid waste incineration fly ash and mechanisms. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 161:166-177. [PMID: 36889123 DOI: 10.1016/j.wasman.2023.02.036] [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: 10/07/2022] [Revised: 02/09/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
The solidification/stabilization technique recommended for the disposal of municipal solid waste incineration (MSWI) fly ashes in developed countries was inappropriate for the treatment in most developing counterparts. In this study, the diatomite and MoS2 nanosheets were synergistically employed to activate the self-alkali-activated cementation of the MSWI fly ashes to achieve efficient solidification, the immobilization of heavy metals (HMs), and the inhibition of chloride release. The compressive strength of 28.61 MPa and the leaching toxicities (mg/L) of Zn, Pb, Cu, Cd, and Cr of 2.26, 0.87, 0.5, 0.06, and 0.22 were obtained from the hardened mortars. Diatomite significantly influenced the self-alkali-activated cementation of the MSWI fly ashes while MoS2 nanosheets played both roles in intensifying the stabilization of HMs and strengthening the binding process by inducing the formation of sodalite and kaolinite, enhancing the growth rates of nucleation, and transforming the layered cementation to the partial and full three-dimensional cementation in the hardened matrix. This study not only verified the feasibility of diatomite and MoS2 in activating the self-alkali-activated cementation of the MSWI fly ashes but also supplied a reliable technique for the harmless disposal and efficient utilization of MSWI fly ashes in developing countries.
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Affiliation(s)
- Tao Huang
- School of Materials Engineering, Changshu Institute of Technology, 215500, China; Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu 215500, China; School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
| | - Dongping Song
- School of Materials Engineering, Changshu Institute of Technology, 215500, China; Suzhou Key Laboratory of Functional Ceramic Materials, Changshu Institute of Technology, Changshu 215500, China
| | - Lulu Zhou
- School of Materials Engineering, Changshu Institute of Technology, 215500, China
| | - YangYang Di
- School of Materials Engineering, Changshu Institute of Technology, 215500, China
| | - Shuwen Zhang
- School of resource environmental and safety engineering, University of South China, 421001, China
| | - Hui Tao
- Chongqing Water Affairs Group Co., Ltd., No. 1, Longjiawan, Yuzhong District, Chongqing 400000, China
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11
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Fan X, Yuan R, Gan M, Ji Z, Sun Z. Subcritical hydrothermal treatment of municipal solid waste incineration fly ash: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 865:160745. [PMID: 36586675 DOI: 10.1016/j.scitotenv.2022.160745] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/10/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Municipal solid waste incineration fly ash (MSWI-FA) is a hazardous waste generated from the incineration process, and the harmless treatment of MSWI-FA has attracted widespread attention. Subcritical hydrothermal treatment is competitive in achieving the harmless treatment and resource recycling of MSWI-FA. It exhibits excellent performance in degrading dioxins, stabilizing heavy metals, and converting MSWI-FA into zeolite or tobermorite at low temperatures. This paper clearly introduces the characteristics of MSWI-FA, roundly summarizes the current research status of treating MSWI-FA by subcritical hydrothermal methods, and deeply clarifies the mechanisms of dioxins degradation, zeolite/tobermorite synthesis, and heavy metals stabilization. Considering the research status of handling MSWI-FA by subcritical hydrothermal methods, future research directions are proposed. Owing to the advantages of high efficiency, energy-saving, and environmental sustainability, subcritical hydrothermal treatment of MSWI-FA exhibits promising prospects for industrialization.
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Affiliation(s)
- Xiaohui Fan
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China
| | - Ruirui Yuan
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China.
| | - Min Gan
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China.
| | - Zhiyun Ji
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China
| | - Zengqing Sun
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China
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Wang P, Cao Y, Yang B, Luo H, Liang T, Yu J, Ding A, Wang L, Li H, Cao H, Ma F, Gu Q, Li F. Leaching Characteristics of Heavy Metals in the Baghouse Filter Dust from Direct-Fired Thermal Desorption of Contaminated Soil. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16504. [PMID: 36554385 PMCID: PMC9778458 DOI: 10.3390/ijerph192416504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
After thermal desorption, the total amount of heavy metals (HMs) is enriched in baghouse filter dust. To further understand the related environmental impact, the leaching characteristics under various conditions must be explored. Therefore, this study aimed to examine the leaching characteristics of seven HMs in the dust generated in the direct-fired thermal desorption process and to compare the differences in heavy metal leaching characteristics in the soil before and after thermal desorption. The leaching characteristics and bioaccessibility of seven HMs-arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)-were analyzed in dust and in soil before and after thermal desorption. The activity of HMs in dust was strong. Therefore, environmental effects and effects on human health should be considered in the treatment of soil and dust after thermal desorption.
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Affiliation(s)
- Panpan Wang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Yunzhe Cao
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Bin Yang
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Huilong Luo
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Tian Liang
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jingjing Yu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Aizhong Ding
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Lina Wang
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Huiying Li
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Hanlin Cao
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Fujun Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qingbao Gu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fasheng Li
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Wei Y, Liu S, Yao R, Chen S, Gao J, Shimaoka T. Removal of harmful components from MSWI fly ash as a pretreatment approach to enhance waste recycling. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:110-121. [PMID: 35810727 DOI: 10.1016/j.wasman.2022.06.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/22/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Municipal solid waste incineration (MSWI) fly ash contains many harmful components that may limit its potential for recycling. An effective pretreatment is therefore required before any recycling can be implemented. In this study, the effects of four pretreatment methods (water washing, CO2-aided washing, CO32--aided washing, and CO2 and CO32--aided washing) on the extraction behavior of chloride, sulfate, and heavy metals were evaluated. Water washing was found to be effective for the extraction of all easily and moderately soluble Cl-bearing salts, achieving Cl extraction ratios of 88%, 90%, and 96% for ash from Chongqing (CQ), Qingdao (QD), and Tianjin (TJ), respectively. Injection of CO2 during washing facilitated decomposition of the hardly soluble Cl-bearing salts, increasing the Cl extraction efficiency by 6% for CQ ash and 9% for QD ash. However, for the TJ ash that contained few insoluble Cl-bearing minerals, CO2 injection decreased the Cl extraction rate. The addition of CO32- had a negative influence on Cl extraction for all ashes, but it slightly promoted sulfate extraction. Despite the high Cl removal rate, only 23-37% of the sulfate and 0.1-12% of heavy metals were removed. Overall, water-based pretreatment, especially CO2-aided washing, significantly altered the physical, chemical, and mineralogical characteristics of the fly ash, making it more suitable for recycling. Consequently, the blending ratio of the fly ash for cement clinker manufacture increased from 0.2 to 0.3% in the raw ash to 3.5-5.5% in the treated ash, enabling the extensive use of ash materials.
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Affiliation(s)
- Yunmei Wei
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China.
| | - Sijie Liu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Ruixuan Yao
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Shuang Chen
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Junmin Gao
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China
| | - Takayuki Shimaoka
- Department of Urban and Environmental Engineering, School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Japan
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14
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MSWI Fly Ash Multiple Washing: Kinetics of Dissolution in Water, as Function of Time, Temperature and Dilution. MINERALS 2022. [DOI: 10.3390/min12060742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Municipal solid waste incineration fly ash (FA) can represent a sustainable supply of supplementary material to the construction industries if it is pre-treated to remove hazardous substances such as chloride, sulfate, and heavy metals. In this paper, the phenomenology associated with a water washing multi-cycle treatment of FA is investigated, focusing attention upon the mineral dissolution process. The efficacy of the treatment is assessed by leaching tests, according to the European Standard, and discussed in light of the occurring mineral phases. The water-to-solid (L/S) ratio is a crucial parameter, along with the number of washing cycles, for removing halite and sylvite, whereas quartz, calcite, anhydrite, and an amorphous phase remain in the solid residue. The sequential extraction method and dissolution kinetics modelling provide further elements to interpret leaching processes, and suggest that dissolution takes place through a two-step mechanism. Altogether, multi-step washing with L/S = 5 is effective in reducing contaminants under the legal limits for non-hazardous waste disposal, while the legal limits for non-reactive or reusable material cannot be completely reached, owing to sulfate and some heavy metals which still leached out from the residue.
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