Optimization of Cl and heavy metal removal during heat treatment of municipal solid waste incineration fly ash and municipal sludge after co-washing.

Autor: Gan M; School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China., Xing J; School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China. xingjinxin930@163.com., Sun Z; School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China., Ji Z; School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China., Fan X; School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China.
Jazyk: angličtina
Zdroj: Environmental monitoring and assessment [Environ Monit Assess] 2024 Dec 16; Vol. 197 (1), pp. 56. Date of Electronic Publication: 2024 Dec 16.
DOI: 10.1007/s10661-024-13532-y
Abstrakt: Heat treatment, known for its detoxification and volume reduction characteristics, is a promising technology for the management of municipal solid waste incineration fly ash (MFA) and municipal sludge (MS). This paper uses the solid residue from MFA and MS after co-washing as the raw material to study the melting properties, phase transformations, changes in Cl content, heavy metal removal efficiency, and leaching toxicity. The results indicated that co-processing of MFA and MS can effectively reduce the melting temperature. The migration of Cl elements was influenced by the CaO/(SiO 2  + Al 2 O 3 ) ratio and the formation of Cl-containing phases. During the heat treatment process, Cr and Ni remained relatively stable, while Zn, Pb, Cu, and Cd were affected by Cl migration. Chlorine can promote the volatilization and escape of these heavy metals, but as Cl became fixed within Ca 10 (SiO 4 ) 3 (SO 4 ) 3 Cl 2 and Ca 5 (PO 4 ) 3 Cl, the removal efficiency decreased. To achieve the highest removal rates for these elements, the addition of MFA should be limited to no more than 20%, and the CaO/(SiO 2  + Al 2 O 3 ) ratio should be below 2.9. After heat treatment, the leaching concentrations of Zn, Pb, Cu, Cr, Cd, and Ni met applicable standards. The findings of this study could provide a method for the treatment of MFA and MS after co-washing and can serve as guidance for heat treatment processes.
Competing Interests: Declarations: Ethical Responsibilities of Authors. All authors have read, understood, and have complied as applicable with the statement on “Ethical responsibilities of Authors” as found in the Instructions for Authors. Conflict of interest: The authors declare no competing interests.
(© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
Databáze: MEDLINE
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