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Title: Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash

Abstract

A major environmental concern associated with coal fly ash is the mobilization of trace elements that may contaminate water. To better evaluate proper use of fly ash, determine appropriate disposal methods, and monitor postdisposal conditions, it is important to understand the speciation of trace elements in fly ash and their possible environmental impact. The speciation of selenium, arsenic, and zinc was determined in five representative Class C fly ash samples from combustion of sub-bituminous Powder River Basin coal using synchrotron-based X-ray absorption spectroscopy to provide an improved understanding of the mechanisms of trace element association with the fly ash. Selenium in all fly ash samples occurs predominantly as Se(IV), with the exception of one sample, in which there was a minor amount of Se(0). Se(0) is likely associated with the high content of unburned coal in the sample. Arsenic exists in the fly ash as a single phase most consistent with calcium pyroarsenate. In contrast, zinc occurs as two distinct species in the silicate glass matrix of the fly ash. This work demonstrates that residual carbon in fly ash may reduce potential Se mobility in the environment by retaining it as less soluble elemental Se instead of Se(IV). Further, thismore » work suggests that As and Zn in Class C fly ash will display substantially different release and mobilization behaviors in aquatic environments. While As release will primarily depend upon the dissolution and hydrolysis of calcium pyroarsenate, Zn release will be controlled by the dissolution of alkaline aluminosilicate glass in the ash.« less

Authors:
; ; ;  [1]
  1. WU
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
OTHER
OSTI Identifier:
1027144
Resource Type:
Journal Article
Journal Name:
Energy and Fuels
Additional Journal Information:
Journal Volume: 25; Journal Issue: 7; Journal ID: ISSN 0887-0624
Country of Publication:
United States
Language:
ENGLISH
Subject:
01 COAL, LIGNITE, AND PEAT; ABSORPTION SPECTROSCOPY; ARSENIC; CALCIUM; CARBON; COAL; COMBUSTION; DISSOLUTION; ELEMENTS; ENVIRONMENTAL IMPACTS; FLY ASH; GLASS; HYDROLYSIS; MONITORS; POWDER RIVER BASIN; SELENIUM; SILICATES; TRACE AMOUNTS; ZINC

Citation Formats

Luo, Yun, Giammar, Daniel E, Huhmann, Brittany L, and Catalano, Jeffrey G. Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash. United States: N. p., 2011. Web. doi:10.1021/ef2005496.
Luo, Yun, Giammar, Daniel E, Huhmann, Brittany L, & Catalano, Jeffrey G. Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash. United States. https://doi.org/10.1021/ef2005496
Luo, Yun, Giammar, Daniel E, Huhmann, Brittany L, and Catalano, Jeffrey G. 2011. "Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash". United States. https://doi.org/10.1021/ef2005496.
@article{osti_1027144,
title = {Speciation of Selenium, Arsenic, and Zinc in Class C Fly Ash},
author = {Luo, Yun and Giammar, Daniel E and Huhmann, Brittany L and Catalano, Jeffrey G},
abstractNote = {A major environmental concern associated with coal fly ash is the mobilization of trace elements that may contaminate water. To better evaluate proper use of fly ash, determine appropriate disposal methods, and monitor postdisposal conditions, it is important to understand the speciation of trace elements in fly ash and their possible environmental impact. The speciation of selenium, arsenic, and zinc was determined in five representative Class C fly ash samples from combustion of sub-bituminous Powder River Basin coal using synchrotron-based X-ray absorption spectroscopy to provide an improved understanding of the mechanisms of trace element association with the fly ash. Selenium in all fly ash samples occurs predominantly as Se(IV), with the exception of one sample, in which there was a minor amount of Se(0). Se(0) is likely associated with the high content of unburned coal in the sample. Arsenic exists in the fly ash as a single phase most consistent with calcium pyroarsenate. In contrast, zinc occurs as two distinct species in the silicate glass matrix of the fly ash. This work demonstrates that residual carbon in fly ash may reduce potential Se mobility in the environment by retaining it as less soluble elemental Se instead of Se(IV). Further, this work suggests that As and Zn in Class C fly ash will display substantially different release and mobilization behaviors in aquatic environments. While As release will primarily depend upon the dissolution and hydrolysis of calcium pyroarsenate, Zn release will be controlled by the dissolution of alkaline aluminosilicate glass in the ash.},
doi = {10.1021/ef2005496},
url = {https://www.osti.gov/biblio/1027144}, journal = {Energy and Fuels},
issn = {0887-0624},
number = 7,
volume = 25,
place = {United States},
year = {Thu Nov 17 00:00:00 EST 2011},
month = {Thu Nov 17 00:00:00 EST 2011}
}