Stabilization of heavy metals in MSWI fly ash using silica fume

Xinying Li; Quanyuan Chen; Yasu Zhou; Mark Tyrer; Yang Yu

doi:10.1016/j.wasman.2014.08.027

Stabilization of heavy metals in MSWI fly ash using silica fume

Xinying Li, Quanyuan Chen, Yasu Zhou, Mark Tyrer, Yang Yu

Research output: Contribution to journal › Article › peer-review

120 Citations (Scopus)

Abstract

The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (²⁷Al and ²⁹Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7days decreased from 0.32mg/L to 0.05mg/L, 40.99mg/L to 4.40mg/L, and 6.96mg/L to 0.21mg/L compared with the MSWI fly ash. After curing for 135days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02mg/L and 0.03mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.

Original language	English
Pages (from-to)	2494-2504
Number of pages	11
Journal	Waste Management
Volume	34
Issue number	12
Early online date	29 Sept 2014
DOIs	https://doi.org/10.1016/j.wasman.2014.08.027
Publication status	Published - Dec 2014
Externally published	Yes

Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in Waste Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Waste Management, [34,] [12], (2014)]
DOI:10.1016/j.wasman.2014.08.027

© 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Keywords

Fly ash
Municipal solid waste
Pozzolanic reaction
Silica fume
Stabilization

ASJC Scopus subject areas

Waste Management and Disposal
Medicine(all)

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.wasman.2014.08.027

Cite this

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title = "Stabilization of heavy metals in MSWI fly ash using silica fume",

abstract = "The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (27Al and 29Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7days decreased from 0.32mg/L to 0.05mg/L, 40.99mg/L to 4.40mg/L, and 6.96mg/L to 0.21mg/L compared with the MSWI fly ash. After curing for 135days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02mg/L and 0.03mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.",

keywords = "Fly ash, Municipal solid waste, Pozzolanic reaction, Silica fume, Stabilization",

author = "Xinying Li and Quanyuan Chen and Yasu Zhou and Mark Tyrer and Yang Yu",

note = "NOTICE: this is the author{\textquoteright}s version of a work that was accepted for publication in Waste Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Waste Management, [34,] [12], (2014)] DOI:10.1016/j.wasman.2014.08.027 {\textcopyright} 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ ",

year = "2014",

month = dec,

doi = "10.1016/j.wasman.2014.08.027",

language = "English",

volume = "34",

pages = "2494--2504",

journal = "Waste Management",

issn = "0956-053X",

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AU - Li, Xinying

AU - Chen, Quanyuan

AU - Zhou, Yasu

AU - Tyrer, Mark

AU - Yu, Yang

N1 - NOTICE: this is the author’s version of a work that was accepted for publication in Waste Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Waste Management, [34,] [12], (2014)] DOI:10.1016/j.wasman.2014.08.027 © 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

PY - 2014/12

Y1 - 2014/12

N2 - The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (27Al and 29Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7days decreased from 0.32mg/L to 0.05mg/L, 40.99mg/L to 4.40mg/L, and 6.96mg/L to 0.21mg/L compared with the MSWI fly ash. After curing for 135days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02mg/L and 0.03mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.

AB - The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (27Al and 29Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7days decreased from 0.32mg/L to 0.05mg/L, 40.99mg/L to 4.40mg/L, and 6.96mg/L to 0.21mg/L compared with the MSWI fly ash. After curing for 135days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02mg/L and 0.03mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China.

KW - Fly ash

KW - Municipal solid waste

KW - Pozzolanic reaction

KW - Silica fume

KW - Stabilization

U2 - 10.1016/j.wasman.2014.08.027

DO - 10.1016/j.wasman.2014.08.027

M3 - Article

C2 - 25277825

AN - SCOPUS:84911442439

SN - 0956-053X

VL - 34

SP - 2494

EP - 2504

JO - Waste Management

JF - Waste Management

IS - 12

ER -

Stabilization of heavy metals in MSWI fly ash using silica fume

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

UN SDGs

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