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Lehmusto J, Tesfaye F, Karlström O, Hupa L. Ashes from challenging fuels in the circular economy. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 177:211-231. [PMID: 38342059 DOI: 10.1016/j.wasman.2024.01.051] [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: 02/16/2023] [Revised: 01/21/2024] [Accepted: 01/30/2024] [Indexed: 02/13/2024]
Abstract
In line with the objectives of the circular economy, the conversion of waste streams to useful and valuable side streams is a central goal. Ash represents one of the main industrial side-products, and using ashes in other than the present landfilling applications is, therefore, a high priority. This paper reviews the properties and utilization of ashes of different biomass power plants and waste incinerations, with a focus on the past decade. Possibilities for ash utilization are of uttermost importance in terms of circular economy and disposal of landfills. However, considering its applicability, ash originating from the heat treatment of chemically complex fuels, such as biomass and waste poses several challenges such as high heavy metal content and the presence of toxic and/or corrosive species. Furthermore, the physical properties of the ash might limit its usability. Nevertheless, numerous studies addressing the utilization possibilities of challenging ash in various applications have been carried out over the past decade. This review, with over 300 references, surveys the field of research, focusing on the utilization of biomass and municipal solid waste (MSW) ashes. Also, metal and phosphorus recovery from different ashes is addressed. It can be concluded that the key beneficial properties of the ash types addressed in this review are based on their i) alkaline nature suitable for neutralization reactions, ii) high adsorption capabilities to be used in CO2 capture and waste treatment, and iii) large surface area and appropriate chemical composition for the catalyst industry. Especially, ashes rich in Al2O3 and SiO2 have proven to be promising alternative catalysts in various industrial processes and as precursors for synthetic zeolites.
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Affiliation(s)
- Juho Lehmusto
- Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Henrikinkatu 2, FI-20500 Turku, Finland.
| | - Fiseha Tesfaye
- Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Henrikinkatu 2, FI-20500 Turku, Finland
| | - Oskar Karlström
- Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Henrikinkatu 2, FI-20500 Turku, Finland; Industrial Engineering and Management, University of Turku, Vesilinnantie 5, 20500 FI-20500 Turku, Finland
| | - Leena Hupa
- Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Henrikinkatu 2, FI-20500 Turku, Finland
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Al-Ejji M, Hassan MK, Youssef K, Elmakaty F, Mehanna H, Sliem M, Irshidat M. Novel surface-treatment for bottom ash from municipal solid waste incineration to reduce the heavy metals leachability for a sustainable environment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 347:119105. [PMID: 37783083 DOI: 10.1016/j.jenvman.2023.119105] [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: 04/20/2023] [Revised: 06/30/2023] [Accepted: 08/30/2023] [Indexed: 10/04/2023]
Abstract
Unconventional treatments can provide a modification to convert ash waste into valuable materials that can be used in various applications. This study focuses on bottom ash (BA) collected from a local incineration plant and characterizes its chemical composition before and after pretreatment by coating with polymers. The toxicity-characteristic leaching procedure (TCLP) was used to identify selected heavy metal leaching after treatment with vinyl-terminated polydimethylsiloxane (PDMS) of different molecular weights. BA coatings were incorporated in two ratios, 0.5% and 1%, by milling to avoid heavy metal leaching. The results showed that all the coating batches had reduced concentrations of copper (Cu), manganese (Mn), and zinc (Zn), whereas the concentrations of chromium (Cr) and cadmium (Cd) showed higher amounts of BAV34 (0.5%) and BAV25 (1%). The treated BA with GP demonstrated percentages of reduction of 70%, 65%, 80%, 75%, 90%, and 80% for Cu, Mn, Ni, Zn, Pb, and Cd, respectively. The milling procedure reduced the particle size of the coated ash. Hydrophobicity was observed in all coating batches compared to untreated BA. The thermogravimetric analysis (TGA) results showed variations between BA and treated BA, which confirmed that PDMS caused surface modification. These features have potential significance for extending the use of coated ash as a sustainable material for construction applications.
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Affiliation(s)
- Maryam Al-Ejji
- Center for Advanced Materials, Qatar University, P.O. Box, 2713, Doha, Qatar
| | - Mohammad K Hassan
- Center for Advanced Materials, Qatar University, P.O. Box, 2713, Doha, Qatar.
| | - Khaled Youssef
- Materials Science and Technology Master Program, College of Arts and Sciences, Qatar University, P O Box, 2713, Doha, Qatar
| | - Farah Elmakaty
- Materials Science and Technology Master Program, College of Arts and Sciences, Qatar University, P O Box, 2713, Doha, Qatar
| | - Hanin Mehanna
- Center for Advanced Materials, Qatar University, P.O. Box, 2713, Doha, Qatar
| | - Mostafa Sliem
- Center for Advanced Materials, Qatar University, P.O. Box, 2713, Doha, Qatar
| | - Mohammad Irshidat
- Center for Advanced Materials, Qatar University, P.O. Box, 2713, Doha, Qatar.
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Long Y, Qiu J, Shen D, Gu F. Transformation and leaching behavior of Pb in hazardous waste incineration fly ash after thermal treatment with addition of Fe 2O 3. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 153:304-311. [PMID: 36179549 DOI: 10.1016/j.wasman.2022.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
This study investigated the leaching behavior of Pb in hazardous waste incineration fly ash (HWIFA) after adding Fe2O3 thermal treatment and revealed the leaching mechanism of Pb from the perspective of phase transformation. The static leaching results showed that at 600 °C-1300 °C, with the addition of Fe2O3 increased, the Pb leaching toxicity continued to decrease. The dynamic results indicated that as the thermal treatment temperature was higher than 1100 °C, the addition of Fe2O3 can effectively inhibit the dynamic leaching of Pb in HWIFA. Meanwhile, the inhibition effect was not very closely related to the amount of Fe2O3. The addition of Fe2O3 can react with PbO to form PbFe12O19, which has a better stability. The appearance of PbFe12O19 was the main reason for adding Fe2O3 to enhanced the immobilization of Pb. However, the amount of Fe2O3 should be carefully controlled to avoid an excessive reducible fraction of Pb in the thermal treated HWIFA, which will affect the long-term stability of Pb.
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Affiliation(s)
- Yuyang Long
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Instrumental Analysis Center of Zhejiang Gongshang University, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Junjian Qiu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Instrumental Analysis Center of Zhejiang Gongshang University, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Dongsheng Shen
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Instrumental Analysis Center of Zhejiang Gongshang University, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
| | - Foquan Gu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Instrumental Analysis Center of Zhejiang Gongshang University, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China.
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Phutthimethakul L, Supakata N. Partial Replacement of Municipal Incinerated Bottom Ash and PET Pellets as Fine Aggregate in Cement Mortars. Polymers (Basel) 2022; 14:polym14132597. [PMID: 35808643 PMCID: PMC9269149 DOI: 10.3390/polym14132597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/16/2022] [Accepted: 06/23/2022] [Indexed: 01/27/2023] Open
Abstract
The objective of this study was to examine the optimal mixing ratio of municipal incinerated bottom ash (MIBA) and PET pellets used as a partial replacement of fine aggregates in the manufacture of cement mortars. As a partial replacement for sand, 15 mortar specimens were prepared by mixing 0%, 10%, 20%, 30%, and 40% municipal incinerated bottom ash (MIBA) (A) and 0%, 10%, and 20% PET pellets (P) in 5 cm × 5 cm × 5 cm cube molds. The cement/aggregate ratio was 1:3, and the water/cement ratio was 0.5 for all specimens. The results showed that the compressive strength of cement mortars decreased when increasing the amount of MIBA and PET pellets. The mortar specimens with 10% PET pellets achieved the highest compressive strength (49.53 MPa), whereas the mortar specimens with 40% MIBA and 20% PET pellets achieved the lowest compressive strength (24.44 MPa). Based on this finding, replacing 10% and 20% sand in cement mortar with only MIBA or only PET pellets could result in compressive strengths ranging from 46.00 MPa to 49.53 MPa.
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Affiliation(s)
- Lalitsuda Phutthimethakul
- International Program in Hazardous Substance and Environmental Management, Graduate School, Chulalongkorn University, Bangkok 10330, Thailand;
| | - Nuta Supakata
- Department of Environmental Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Research Group (STAR): Waste Utilization and Ecological Risk Assessment, The Ratchadaphiseksomphot Endowment Fund, Chulalongkorn University, Bangkok 10330, Thailand
- Correspondence:
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Zhang Z, Wang Y, Zhang Y, Shen B, Ma J, Liu L. Stabilization of heavy metals in municipal solid waste incineration fly ash via hydrothermal treatment with coal fly ash. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 144:285-293. [PMID: 35427900 DOI: 10.1016/j.wasman.2022.03.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 03/14/2022] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
The environmental risk of heavy metals in hazardous municipal solid waste incineration fly ash (FA) is one of the most important concerns for its safely treating and disposing. This study investigated the stabilization behavior of heavy metals in FA using coal fly ash (CFA) as an additive via hydrothermal treatment. The effects of water washing pre-treatment and FA/CFA ratio on leaching behavior, speciation evolution, and risk assessment of heavy metals were studied. The results showed that 96.6-98.0 % of Cl can be effectively removed by water washing pre-treatment and hydrothermal treatment. Most heavy metals (Cr, Cu, Ni, Pb and Zn) (>91.5 %) were stabilized in the hydrothermal product, rather than transferred to liquid phase. Tobermorite can be synthesized by adjusting Ca/Si ratio with the addition of CFA. The heavy metals were transferred into more stable residue fractions with increasing CFA addition, which resulted in the significant reduction of leaching concentrations and risk assessment code (RAC) of heavy metals. Among, the product with 30% CFA exhibited the most superior performance with the lowest leaching concentrations of heavy metals and RAC was at no risk level (<1). In addition, the economic performance of hydrothermal treatment exhibited a potential advantage by comparing with FA-to-cement, FA-to-glass slags and FA-to-chelating agent & cement solidification/stabilization. Therefore, the hydrothermal treatment coupled with water washing pre-treatment would be a promising method for the detoxification of FA, as well as synergistic treatment of FA and CFA.
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Affiliation(s)
- Zhikun Zhang
- School of Energy & Environmental Engineering, Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin 300401, PR China
| | - Yanli Wang
- School of Energy & Environmental Engineering, Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin 300401, PR China
| | - Yuqi Zhang
- School of Energy & Environmental Engineering, Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin 300401, PR China
| | - Boxiong Shen
- School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300401, PR China.
| | - Jiao Ma
- School of Energy & Environmental Engineering, Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin 300401, PR China
| | - Lina Liu
- College of Environmental Science and Engineering, MOE Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300350, PR China.
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Matsumoto H, Takaoka M. The application of multiple advanced chloride removal methods to synthesized Friedel's salt and municipal solid waste incineration bottom ash. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 141:27-34. [PMID: 35091317 DOI: 10.1016/j.wasman.2022.01.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/05/2022] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
To recycle municipal solid waste incineration bottom ash as a cement raw material, it is important to reduce the Cl concentration in the ash. However, the reduction of chlorides by washing only has limited success due to the presence of insoluble Friedel's salt (FS) in the ash. Although some studies on the decomposition of FS and the application of advanced chloride removal methods to bottom ash have been reported, few studies have compared the effects of different removal methods. Moreover, due to the complex ash composition, it is also necessary to compare the effects on different ashes and pure FS. Therefore, in this study, we applied five advanced chloride removal methods to synthesized FS and two types of bottom ash (FS-High and FS-Low), and compared the effects. For both FS and bottom ash, all methods promoted chloride dissolution more than washing only. For FS, aging was the most effective method, with a Cl removal ratio of 73%. In contrast, for ash FS-High, aging increased the Cl removal ratio to 80% and decreased the Cl content to 2800 mg/kg. The FS-derived peak observed in an X-ray diffraction analysis disappeared following aging. For ash FS-Low, acid washing increased the Cl removal ratio to 64% and decreased the Cl content to 1800 mg/kg. The treatment with the highest removal ratio in each ash had the lowest pH. There was a significant correlation between pH and the Cl removal effect. The Cl remaining after the application of the methods was likely associated with Na.
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Affiliation(s)
- Hitomi Matsumoto
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura C1-3, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Masaki Takaoka
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura C1-3, Nishikyo-ku, Kyoto 615-8540, Japan.
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Wong G, Gan M, Fan X, Ji Z, Chen X, Wang Z. Co-disposal of municipal solid waste incineration fly ash and bottom slag: A novel method of low temperature melting treatment. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124438. [PMID: 33229258 DOI: 10.1016/j.jhazmat.2020.124438] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/14/2020] [Accepted: 10/29/2020] [Indexed: 06/11/2023]
Abstract
Conventional melting for disposing municipal solid waste incineration (MSWI) fly ash or bottom slag needed high temperature and consumed high energy. High calcium content in fly ash and high silicon content in bottom slag brought them high melting point, respectively. Based on the analysis of chemical composition and phase diagram, suitable contents, namely 30%-40% CaO, 45%-60% SiO2 and 10%-15% Al2O3, were proposed to obtain a lower-melting-point mixture system. When the mass ratio of fly ash to bottom slag was 1:5, lowest melting point can be obtained. It was 1,190 ℃, lower than that of fly ash (1,448 ℃) and bottom slag (1,310 ℃). The toxicity characteristic leaching procedure of slags obtained from low melting treatment met the leaching toxicity of Chinese standard GB 5085.3-2007, and the slags containing about 25 wt% CaO, 10 wt% Al2O3 and 45 wt% SiO2 can be used for preparing CaO-Al2O3-SiO2 glass ceramics. The co-process of fly ash and bottom slag realized the low temperature melting treatment with low energy consumption.
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Affiliation(s)
- Guojing Wong
- 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.
| | - Xiaohui Fan
- 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
| | - Xuling Chen
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China
| | - Zhuangzhuang Wang
- School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China
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Properties of Alkali Activated Lightweight Aggregate Generated from Sidoarjo Volcanic Mud (Lusi), Fly Ash, and Municipal Solid Waste Incineration Bottom Ash. MATERIALS 2020; 13:ma13112528. [PMID: 32498382 PMCID: PMC7321484 DOI: 10.3390/ma13112528] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/29/2020] [Accepted: 05/30/2020] [Indexed: 11/16/2022]
Abstract
Production of artificial lightweight aggregate (LWA) from industrial by-products or abundant volcanic mud is a promising solution to prevent damaging the environment due to the mining of natural aggregate. However, improvements are still needed in order to control the high water absorption of LWA and strength reduction in resulting concrete or mortar. Hence in this research, fly ash, municipal solid waste incineration bottom ash (MSWI BA), and Sidoarjo volcanic mud (Lusi) were employed as a precursor and activated using NaOH 6 M and Na2SiO3 in producing LWA. The influence of the type of the precursors on the physical properties of resulting LWA was investigated. The effect of replacing natural fine aggregate with the resulting LWA on the compressive strength and volume density of mortar was also determined. Finer particles, a high amount of amorphous phase, and low loss on ignition (LOI) of the raw material improved the properties of resulting LWA. Mortar compressive strength was decreased by 6% when replacing 16% by volume of natural fine aggregate with fly ash based LWA. Compared to the expanded clay LWA, the properties of alternative LWAs in this study were slightly, but not significantly, inferior. Alternative LWA becomes attractive when considering that expanded clay LWA requires more energy during the sintering process.
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Alam Q, Lazaro A, Schollbach K, Brouwers HJH. Chemical speciation, distribution and leaching behavior of chlorides from municipal solid waste incineration bottom ash. CHEMOSPHERE 2020; 241:124985. [PMID: 31606001 DOI: 10.1016/j.chemosphere.2019.124985] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
Municipal solid waste incineration (MSWI) bottom ash is an environmentally harmful solid waste that cannot be recycled without pre-treatment. The chloride content in bottom ash (BA) is a major obstacle that restricts its application as secondary building materials. Here, the chemical speciation of the chlorides in BA is systematically studied with multiple analytical techniques, i.e., quantitative XRD, microanalysis and XPS. In addition to halite (NaCl), several chloride-rich minerals are present in BA. These phases are hydrous metal oxides, ettringite, decomposed hydration products (C4A3) and incineration slag with a chloride content of 3.2%, 1.4%, 2.1% and 1.3%, respectively. For the first time, the real-time leaching profiles of chloride (up to 80 h) from BA were obtained with a chloride-ion specific electrode to explain the leaching mechanism. In the initial stage of leaching, highly soluble alkali salts (NaCl) and physisorbed chlorides (especially those adsorbed on hydrous metal oxides) are released, which is controlled by diffusion. Later, the leaching is controlled by the solubility/reactivity of the chloride-containing phases, such as ettringite and incineration slag. The results show that the release of chloride is not only a diffusion-controlled process, as reported in the literature, but also a reaction-controlled phenomenon, during which the chloride-rich phases decompose and release chlorides that are associated with them via sorption/incorporation.
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Affiliation(s)
- Qadeer Alam
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600, MB, Eindhoven, the Netherlands.
| | - Alberto Lazaro
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600, MB, Eindhoven, the Netherlands
| | - Katrin Schollbach
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600, MB, Eindhoven, the Netherlands; Tata Steel, R&D, Microstructure & Surface Characterization (MSC), P. O. Box 10.000, 1970, CA, Ijmuiden, the Netherlands
| | - H J H Brouwers
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600, MB, Eindhoven, the Netherlands
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MSWI Bottom Ash Application to Resist Sulfate Attack on Concrete. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9235091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This research provides a strategy for partially replacing cement with municipal solid waste incineration (MSWI) bottom ash (BA) to improve the performance of concrete against sulphate attack. Mortar strength tests were performed firstly to evaluate the hydration activity of the ground BA. Concrete specimens were cured in standard conditions and immersed in a solution that contained 10% sodium sulfate. Then, the compressive strength of these specimens was measured to investigate the mechanical properties and durability of the concrete. Next, the capillary porosity of the concrete was determined from the volume fractions of water lost in specimens. Finally, the transport of the sulphate solution in concrete was analyzed using capillary rise, crystallization rate, and solution absorption tests. The results indicated that BA had a certain hydration activity. The equivalent replacement of cement by BA decreased the compressive strength of the specimens but increased the durability of the concrete. There was an excellent correlation between capillary rise height, sulfate solution absorption amount, crystallization rate, and coarse capillary porosity. The addition of BA can decrease the coarse capillary porosity and further slow the capillary transport and crystallization of sulfate solution in concrete. Overall, the replacement of cement with BA can improve the durability of concrete and actualize the utilization of MSWI residues as a resource.
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Alam Q, Schollbach K, Rijnders M, van Hoek C, van der Laan S, Brouwers HJH. The immobilization of potentially toxic elements due to incineration and weathering of bottom ash fines. JOURNAL OF HAZARDOUS MATERIALS 2019; 379:120798. [PMID: 31255851 DOI: 10.1016/j.jhazmat.2019.120798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
Incineration bottom ash fines (≤ 125 μm) are known to contain potentially toxic elements (PTEs) and inorganic salts. The most abundant PTEs in the fines were Zn (0.5%), Cu (0.25%), Pb (0.12%), Mn (0.08%) and Cr (0.03%). The systematic quantification of the mineral phases and PTEs associated with them was performed with a multimethod approach using quantitative XRD, phase mapping with PhAse Recognition and Characterization (PARC) software and microprobe analysis. The mineral phases in the fines can be categorized as follows: 1) residual phases (e.g., quartz), 2) incineration phases (e.g., melilitic slag and iron oxides) and 3) quenching/weathering phases (e.g., calcite, ettringite, gypsum, hydrous Fe- and Al-oxides). Among the incineration phases, the melilitic slag was observed to contain Cr, Cu and Zn with 0.02%, 0.13% and 0.19%, respectively. In order of predominance, the weathering phases containing the most PTEs were: calcite < ettringite < hydrous Al-oxides < hydrous Fe-oxides. More than 70% of the phases in the BA fines were formed during incineration and weathering processes that explain the enrichment of PTEs in the smaller particles. During the one-batch leaching test, dissolution of weathering phases, especially ettringite, was observed (total mass loss: 7.2%).
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Affiliation(s)
- Qadeer Alam
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, the Netherlands.
| | - Katrin Schollbach
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, the Netherlands; Tata Steel, R&D, Microstructure & Surface Characterization (MSC), P. O. Box 10.000, 1970 CA, Ijmuiden, the Netherlands
| | - Marco Rijnders
- Tata Steel, R&D, Microstructure & Surface Characterization (MSC), P. O. Box 10.000, 1970 CA, Ijmuiden, the Netherlands
| | - Corrie van Hoek
- Tata Steel, R&D, Microstructure & Surface Characterization (MSC), P. O. Box 10.000, 1970 CA, Ijmuiden, the Netherlands
| | - Sieger van der Laan
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, the Netherlands; Tata Steel, R&D, Microstructure & Surface Characterization (MSC), P. O. Box 10.000, 1970 CA, Ijmuiden, the Netherlands
| | - H J H Brouwers
- Department of the Built Environment, Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, the Netherlands
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