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He H, Lu S, Peng Y, Tang M, Zhan M, Lu S, Xu L, Zhong W, Xu L. Emission characteristics of dioxins during iron ore Co-sintering with municipal solid waste incinerator fly ash in a sintering pot. Chemosphere 2022; 287:131884. [PMID: 34474380 DOI: 10.1016/j.chemosphere.2021.131884] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/27/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
The disposing of municipal solid waste incineration(MSWI) fly ashes containing dioxins is an intractable problems. Co-sintering is one of the most ideal methods to dispose MSWI fly ash, because it not only degrades the dioxins but also makes it possible to re-utilize MSWI fly ashes. In the present study, MSWI fly ash(FA) and water washed MSWI fly ash(WFA) were added into the sinter raw mixture in a lab-scale sintering pot. Different effects of fly ash and water washed fly ash on emission characteristics of dioxins were studied, and possible pathways to form dioxins were discussed in detail. During co-sintering, at least 88.9%, 99.1% of dioxins brought in by FA, WFA was decomposed, respectively, and re-synthesis with a significant distribution characteristic of dioxins originated from sintering process. In the preheating and dry zone, the recombination and condensation reaction of precursors were the main formation pathways of 2,3,7,8-PCDDs in the sintering process and 2,3,7,8-PCDFs were formed by de novo synthesis. In addition, the resynthesis process was affected by chlorine and calcium brought in by fly ash. Sufficient chlorine boosted the chlorination of reactants while calcium increased the residence time, causing the emission concentration of toxic dioxins and the adding ratio were nonlinearly dependent. Therefore, the maximum proportion of water washed MSWI fly ash that can be added into the sintering process was 0.5 wt.%. Besides, the possible pathways to form dioxins were proposed.
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Affiliation(s)
- Hao He
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, PR China
| | - Shengyong Lu
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, PR China
| | - Yaqi Peng
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, PR China.
| | - Minghui Tang
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, PR China.
| | - Mingxiu Zhan
- China Jiliang University, Hangzhou, Zhejiang, 310027, PR China
| | - Siping Lu
- Baowu Group Environmental Resources Technology Co. Ltd., Shanghai, 201900, PR China
| | - Li Xu
- Baowu Group Environmental Resources Technology Co. Ltd., Shanghai, 201900, PR China
| | - Wei Zhong
- Baowu Group Environmental Resources Technology Co. Ltd., Shanghai, 201900, PR China
| | - Liming Xu
- Baowu Group Environmental Resources Technology Co. Ltd., Shanghai, 201900, PR China
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