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Wei W, Liu Q, Zhang Z, Lisak G, Yin K, Fei X. Categorization of leaching behaviors of elements from commercially treated incineration bottom ash in Singapore. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 178:339-350. [PMID: 38430748 DOI: 10.1016/j.wasman.2024.02.045] [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: 09/04/2023] [Revised: 02/24/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Leaching of potentially hazardous substances, especially the heavy metals from Incineration Bottom Ash (IBA) is a major problem in its recyclable usage. To address this concern, treatment of IBA is indispensable before it can be reused. IBA subjected to laboratory-scale treatment typically yields clearer conclusions in terms of leaching behaviors, benefiting from the controlled laboratory environment. However, the leaching behaviors of commercially treated IBA appear to be more ambiguous due to the complex and comprehensive nature of industrial-scale treatments, where multiple treatment techniques are involved concurrently. Furthermore, treatment efficiencies vary among different plants. In this study, three types of commercially treated IBA were sampled from leading waste treatment companies in Singapore. Characterization and leaching tests were performed on the treated IBAs in both standardized and modified manners to simulate various scenarios. Besides deionized water, artificial seawater was used as a leachant in leaching tests for simulating seawater intrusion. The results reveal the promoting effect of seawater on the leaching levels of several elements from three types of treated IBA, which may require special attention for IBA application and landfill near the coast. Furthermore, the elements examined in these three types of commercially treated IBA generally comply with the non-hazardous waste acceptance criteria outlined in Council Decision, 2003/33/EC (2003), except Sb. By combining two leaching tests, the elements were categorized into different types of leaching behavior, making it possible to prepare and respond to the concerning leaching scenarios in future engineering applications.
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Affiliation(s)
- Wei Wei
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore
| | - Qian Liu
- Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore
| | - Zhibo Zhang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Grzegorz Lisak
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore
| | - Ke Yin
- School of Biology and the Environment, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Xunchang Fei
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, 1 Cleantech Loop, 637141, Singapore.
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2
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Duan Y, Liu X, Hong W, Khalid Z, Lv G, Jiang X. Leaching behavior and comprehensive toxicity evaluation of heavy metals in MSWI fly ash from grate and fluidized bed incinerators using various leaching methods: A comparative study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169595. [PMID: 38154649 DOI: 10.1016/j.scitotenv.2023.169595] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 11/30/2023] [Accepted: 12/20/2023] [Indexed: 12/30/2023]
Abstract
Municipal solid waste incineration fly ash (MSWI FA) is a kind of hazardous waste that contains a substantial amount of heavy metals. To facilitate the appropriate treatment of MSWI FA, the leaching behavior of heavy metals was evaluated in MSWI FA from various sources using different leaching methods. Nine kinds of MSWI FA were investigated using three kinds of batch leaching tests (TCLP, HJ/T 300, and EN12457-2). The chemical form distributions of heavy metals in MSWI FA were obtained by sequential extraction procedures (SEPs) and the environmental risk posed by MSWI FA was comprehensively evaluated. The results showed that the grate and fluidized bed MSWI FA performed differently in various leaching methods, which was mainly dependent on the leachate pH and the chemical form distributions of the heavy metals. In addition, the BCR SEP was more suitable for the fractionation of heavy metals and the environmental risk assessment of MSWI FA when compared with Tessier's SEP. The overall pollution toxicity index allowed a comprehensive risk assessment specific to the leaching environment, thereby offering valuable guidelines for the stabilization or resource-based treatment of MSWI FA.
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Affiliation(s)
- Yin Duan
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China
| | - Xiaobo Liu
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China
| | - Wenjuan Hong
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China
| | - Zeinab Khalid
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China
| | - Guojun Lv
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China
| | - Xuguang Jiang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China; Zhejiang University Qingshanhu Energy Research Center, Linan, Hangzhou 311305, China.
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Hu Y, Zhao L, Zhu Y, Zhang B, Hu G, Xu B, He C, Di Maio F. The fate of heavy metals and salts during the wet treatment of municipal solid waste incineration bottom ash. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 121:33-41. [PMID: 33341692 DOI: 10.1016/j.wasman.2020.11.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/04/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Bottom ash contains unfavorable contaminants that could leach into the circulating water used for wet treatment, and its improper disposal of bottom ash could cause ecological pollution. This study was to discuss the partition of heavy metals and salts of bottom ash into circulating water and ash stockpile runoff in wet treatment plants in southern China. The leachability of bottom ash before and after the wet treatment was also investigated. The checked heavy metals Pb, Cu, and Ni and dissolved salts Cl- and SO42- show lower available fractions in leachate from the treated bottom ash than that in raw bottom ash. Circulating water is contaminated by target heavy metals, which the contents of Cu and Pb is higher than its limit for urban wastewater discharge. The circulating water owned the highest concentration of Cl- and SO42-, above10000 mg/L, and 1100 mg/L, which is far higher than the limits. The detected heavy metals, Cl- and SO42- in runoff also exceed the limits for urban wastewater discharge. Locations for bottom ash processing and storage sites should be selected to control and prevent any leaching and runoff impacts. Any runoff and circulation water should be discharged to the lined landfill's leachate collection system or suitable industrial wastewater treatment facilities.
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Affiliation(s)
- Yanjun Hu
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 HangZhou, China.
| | - Lingqin Zhao
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 HangZhou, China
| | - Yonghao Zhu
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 HangZhou, China
| | - Bennong Zhang
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 HangZhou, China
| | - Guixiang Hu
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 HangZhou, China
| | - Bin Xu
- Shanghai Urban Planning and Design Research Institute, Tongren Road 331#, 200040 ShangHai, China.
| | - Changxuan He
- Shanghai Urban Planning and Design Research Institute, Tongren Road 331#, 200040 ShangHai, China
| | - Francesco Di Maio
- Delft University of Technology, P.O. Box 5048, 2628 CN Delft, the Netherlands
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Prabhakar AK, Cadiam Mohan B, Tay TS, Lee SSC, Teo SLM, Wang CH. Incinerated Sewage Sludge Bottom Ash- Chemical processing, Leaching patterns and Toxicity testing. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123350. [PMID: 32736175 DOI: 10.1016/j.jhazmat.2020.123350] [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: 01/24/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
Sewage sludge bottom ash, which is the major fraction obtained from the incineration of sewage sludge was treated with various organic and inorganic acids for heavy metal removal, along with a comparative phosphate treatment for heavy metal fixation. Malonic acid, an organic acid, was found to remove heavy metals better as compared to nitric acid, a strong inorganic acid. The acid treated samples were further examined for heavy metal leaching, followed by marine toxicity/abnormality testing of the leachates, where acid treated and phosphate treated ash leachate displayed higher (with malonic acid proving to be most toxic) and similar toxicity profiles as compared to raw ash leachate respectively. Raw ash was tested for its leaching patterns at different liquid/solid ratios(L/S = 5 and 10), salinities and time points (24, 48 and 72 h), where the leaching was found to saturate at L/S = 5 and at 24 h with varied salinity effecting the leaching insignificantly. When raw ash was benchmarked against concrete sand for marine toxicity, a material commonly used for land reclamation, acute toxicity patterns were found to be mostly similar except in case of the sea urchin embryonic assay, where toxicity was detected, indicating the sensitivity of the assay to residual levels of heavy metals. The raw ash was also tested against human cell lines where it displayed size and dose-dependent toxicity. To enable the use of ash for environment applications such as coastal reclamation, appropriate treatments are required to minimize leaching of potential harmful contaminants and this study demonstrates the importance of post-treatment of ash on its subsequent toxicity to organisms.
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Affiliation(s)
- Arun Kumar Prabhakar
- NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore
| | - Babu Cadiam Mohan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore
| | - Teresa Stephanie Tay
- St John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - Serina Siew-Chen Lee
- St John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - Serena Lay-Ming Teo
- St John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - Chi-Hwa Wang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
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Li T, Shi Y, Li X, Zhang H, Pi K, Gerson AR, Liu D. Leaching behaviors and speciation of cadmium from river sediment dewatered using contrasting conditioning. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 263:114427. [PMID: 32247921 DOI: 10.1016/j.envpol.2020.114427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/12/2020] [Accepted: 03/19/2020] [Indexed: 06/11/2023]
Abstract
Chemical conditioning is an effective strategy for improved river sediment dewatering affecting both the dewatering efficiency and subsequent resource utilization of the dewatered cake. Two types of conditioning agents, polyaluminium chloride (PAC)/cationic polyacrylamide (PAM) (coagulation precipitation conditioning agent, referred to as P-P conditioning) and ferrous activated sodium persulfate (advanced oxidation conditioning agent, referred to as F-S conditioning) were examined. With increasing leach liquid to solid (L/S) ratio the concentration of Cd for the real time leachates from the dewatered cakes decreased, but the leaching ratio of Cd in both P-P and F-S dewatered cakes increased. With the same L/S, the leaching ratio was reduced for both types of conditioning, as compared to no conditioning, with the leaching ratio being least with F-S conditioning. The leaching ratio of Cd in the dewatered cake with L/S of 100 L kg-1 was reduced from 21.3% of the total Cd present for the un-conditioned sediment to 12.5% upon P-P conditioning and 11.6% upon F-S conditioning. Furthermore, the different conditioning methods affected the Cd speciation in the dewatered cakes reducing the easy-to-leach speciation of exchangeable and carbonate-bound Cd species and increasing the potential-to-leach speciation of iron-manganese oxide and organically bound Cd species and also the difficult-to-leach species. Risk assessment indicates that the risk due to Cd leaching from the dewatered cakes at L/S of 100 L kg-1 was reduced from high risk to medium risk after P-P and F-S conditioning with reduced bioavailability.
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Affiliation(s)
- Tian Li
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China
| | - Yafei Shi
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China; Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, Hubei, 430068, China.
| | - Xiaoran Li
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China
| | - Huiqin Zhang
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China
| | - Kewu Pi
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China; Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, Hubei, 430068, China
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, 7109, Australia
| | - Defu Liu
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, Hubei, 430068, China; Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, Hubei, 430068, China
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Yin K, Chan WP, Dou X, Lisak G, Chang VWC. Kinetics and modeling of trace metal leaching from bottom ashes dominated by diffusion or advection. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 719:137203. [PMID: 32114221 DOI: 10.1016/j.scitotenv.2020.137203] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 05/14/2023]
Abstract
Leaching kinetics of trace metals from incineration bottom ashes (IBA) under diffusion and advection were investigated through leaching tests of compacted granulars of IBAs and their packed columns with seawater eluent for 64 days and 26 days, respectively. Metal fluxes were distinct among species while linearily decreased at log-log scales as a function of time. Short-term environmental risks for Cu, Ni and Pb were identified under advection. The metal leaching behavior generally followed the pseudo-second order under diffusion, while the pseudo-first order kinetics under advection. Investigated metals may be further identified as diffusion- (As, Cd, Cr, Sb) and advection-dominant species (Ba, Cu, Ni, Pb, Zn) according to their fluxes, which interestingly corresponded to the low- (5.19-147.90 mg·kg-1) and high-value (116.46-2398.44 mg·kg-1) of their metal distribution from IBAs, respectively. Considering the general higher metal release, decay models were employed to simulate the column leaching results. Particularly, Type-II model based on two-site assumptions fit much better to the experimental data, unveiling significant yet retarded release (in 1-2 pore volumes) of certain metals from the slow-reaction sites. Further investigation on the release of bulk parameters unveiled that, there existed rebounded leaching rates primarily ascribed to the IBA heterogeneity.
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Affiliation(s)
- Ke Yin
- Department of Environmental Engineering, School of Biology and the Environment, Nanjing Forestry University, 159 Longpan Road, Nanjing 230017, Jiangsu Province, China.
| | - Wei-Ping Chan
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - Xiaomin Dou
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - Grzegorz Lisak
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore.
| | - Victor Wei-Chung Chang
- Department of Civil Engineering, 23 College Walk, Monash University, Victoria 3800, Australia.
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Yin K, Chan WP, Dou X, Lisak G, Wei-Chung Chang V. Comparison and modeling of leachate transportation dominated by the field permeability with an anisotropic characteristic based on a large-scale field trial study. CHEMOSPHERE 2020; 242:125254. [PMID: 31896190 DOI: 10.1016/j.chemosphere.2019.125254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/27/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
Permeability significantly affects leachate transportation. Yet, there often exists a gap for its measurements between laboratory and the field. To predict the fate and transport of heavy metals from IBA leaching, a large-scale field trial study was performed using a big column (d × h = 3 m × 5.5 m) packed with 1-m thickness of IBA (approx. 10.6 tons) overlaid by 4-m sand layer. The determined field permeability (kF) was compared with that achieved from the laboratory, demonstrating a large disparity as much as 4 orders of magnitude likely due to IBA self-compaction. Indeed, back calculation using Blake-Kozeny's equation unveiled that, the "effective" diameters were significantly reduced by 21-46%. kF also demonstrated an anisotropic characteristic associated with fingered flows, trapped bubbles and heterogeneous consolidation/cementation efficiencies. To quantify the effects by kF, we ran a mechanistic model to simulate the transport of 11 heavy metals under advection (dh/dx = 0.05 m/m), indicating dramatically prolonged breakthrough time from days to centuries. Interestingly, breakthrough time was comparable among various metal ions (0-16.6% of RSD), suggesting their synchronous movements. Metal flux under kF was predicted in the end to address its toxicity potential, demonstrating limited environmental impacts in presence of the USEPA criterion.
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Affiliation(s)
- Ke Yin
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China; Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
| | - Wei-Ping Chan
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore
| | - Xiaomin Dou
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore
| | - Grzegorz Lisak
- Residue and Resource Reclamation Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
| | - Victor Wei-Chung Chang
- Department of Civil Engineering, 23 College Walk, Monash University, Victoria 3800, Australia.
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Luo H, Cheng Y, He D, Yang EH. Review of leaching behavior of municipal solid waste incineration (MSWI) ash. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 668:90-103. [PMID: 30852230 DOI: 10.1016/j.scitotenv.2019.03.004] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 06/09/2023]
Abstract
Incineration is widely adopted in modern waste management because it provides an effective way to minimize municipal solid waste that needs to be disposed of in landfills. The ash residue is often disposed by landfilling. Alternatively, the incineration ash may be recycled and reused for various applications. The crucial issues, however, are the leaching of harmful elements during the use and the end-of-life phases. This review summarizes extensive studies on leaching behavior of municipal solid waste incineration ash. Specifically, pollutants generated through leaching, factors governing leaching, methodologies to study leaching, leaching mechanisms, and treatments to reduce leaching. Many types of pollutants are generated through leaching from municipal solid waste incineration ash, in which heavy metals and organic contaminants are the most toxic and concerned. Ash properties, pH and liquid to solid ratio are the main factors governing municipal solid waste incineration ash leaching. Leaching behavior of municipal solid waste incineration ash is complicated and existing methods to evaluate leaching may not be able to represent the field conditions. Solubility and sorption are the two major leaching mechanisms. Many treatment methods have been proposed. However, not all methods are effective and some approaches are associated with high energy and high cost, which makes them less economically feasible and attractive.
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Affiliation(s)
- Hongwei Luo
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; Energy Research Institute, Nanyang Technological University, Singapore 637553, Singapore
| | - Ying Cheng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Dongqin He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
| | - En-Hua Yang
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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Caviglia C, Confalonieri G, Corazzari I, Destefanis E, Mandrone G, Pastero L, Boero R, Pavese A. Effects of particle size on properties and thermal inertization of bottom ashes (MSW of Turin's incinerator). WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 84:340-354. [PMID: 30691909 DOI: 10.1016/j.wasman.2018.11.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/17/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
The aim of this study is twofold: (i) characterization of the bottom ashes from the Incinerator plant of the city of Turin (northern Italy), in terms of their chemical/phase compositions and capacity to release heavy metals in leachates, as a function of particle size; (ii) investigation of thermal treatments' efficacy to promote inertization of the same bottom ashes, exploring time-temperature ranges with t ≤ 6 h and T ≤ 1000 °C. Special attention is paid to macro-sampling techniques in order to have samples that are representative of the average bottom ashes production. Micro-XRF, ICP-OES, SEM-EDS, Ion Chromatography and X-ray powder diffraction were used to investigate bottom ashes and leachates. Bottom ashes are mainly constituted by an amorphous phase, ∼66-97 wt%, regardless of particle size; the remaining phases are quartz, calcite, Fe-oxides, melilite and other minor crystalline materials. The amorphous phase exhibits a relevant dependence on particle size, and undergoes dissolution in water up to 20 wt%, thus being the most important component in affecting chemical species release. The smaller the bottom ashes' particle size, the more the heavy metals (major species: Zn, Cu, Ti, Pb) and calcium contents increase, whereas silicon's decreases. Electrolytic current observations in combination with phase/chemical composition and metals release as a function of particle size, suggest that bottom ashes partition into two classes, i.e. ≥1 and <1 mm, for inertization purposes. Thermal treatments exhibit partial efficacy to curb heavy metals mobility: whilst they reduce Cu release, they lead to a inverse effect in the case of Cr.
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Affiliation(s)
- Caterina Caviglia
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy.
| | - Giorgia Confalonieri
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy
| | - Ingrid Corazzari
- Chemistry Department, Università degli Studi di Torino, Via Pietro Giuria 7, 10125 Torino, Italy
| | - Enrico Destefanis
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy
| | - Giuseppe Mandrone
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy
| | - Linda Pastero
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy
| | - Renato Boero
- Trattamento Rifiuti Metropolitani - TRM SpA, Via Paolo Gorini 50, 10137 Torino, Italy
| | - Alessandro Pavese
- Earth Sciences Department, Università degli Studi di Torino, Via Valperga Caluso 35, 10125 Torino, Italy
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Lin WY, Ng WC, Wong BSE, Teo SLM, Sivananthan GD, Baeg GH, Ok YS, Wang CH. Evaluation of sewage sludge incineration ash as a potential land reclamation material. JOURNAL OF HAZARDOUS MATERIALS 2018; 357:63-72. [PMID: 29864689 DOI: 10.1016/j.jhazmat.2018.05.047] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/17/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
This study evaluated the potential of utilising sewage sludge incineration ash as a land reclamation material. Toxicity assessment of the leachate of the ash was carried out for both terrestrial and marine organisms. Both the fruit fly Drosophila melanogaster and barnacle Amphibalanus amphitrite showed that both bottom and fly ash leached at liquid-to-solid (L/S) ratio 5 did not substantially affect viabilities. The leachate carried out at L/S 10 was compared to the European Waste Acceptance Criteria and the sewage sludge ashes could be classified as non-hazardous waste. The geotechnical properties of the sewage sludge ash were studied and compared to sand, a conventional land reclamation material, for further evaluation of its potential as a land reclamation material. It was found from direct shear test that both bottom and fly ashes displayed similar and comparable shear strength to that of typical compacted sandy soil based on the range of internal friction angle obtained. However, the consolidation profile of bottom ash was significantly different from sand, while that of fly ash was more similar to sand. Our study showed that the sewage sludge ash has the potential to be used as a land reclamation material.
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Affiliation(s)
- Wenlin Yvonne Lin
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore
| | - Wei Cheng Ng
- NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore
| | - Belinda Shu Ee Wong
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, 117594, Singapore
| | - Serena Lay-Ming Teo
- Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - Gayathiri D/O Sivananthan
- Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - Gyeong Hun Baeg
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, 4 Medical Drive, 117594, Singapore
| | - Yong Sik Ok
- Korea Biochar Research Center, O-Jeong Eco-Resilience Institute (OJERI) & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Chi-Hwa Wang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
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