Doctoral Dissertations


Tingzhi Su


"Leaching of trace elements raises environmental concerns in coal fly ash disposal and reuse. US EPA is in the process of creating the first national rule on coal ash management. However, due to the complexity of coal fly ash composition, the leaching characteristics of trace elements are not well understood. Meanwhile, driven by the tightening emission regulations, new types of coal fly ashes are continuously generated as a result of the technological evolution at coal energy industry. The changing landscape highlights the needs for a comprehensive database to assess the leaching characteristics of different types of coal fly ashes, evaluation of the emission control technology on the ashes produced in the power industry, a practical method to predict the leachability of trace contaminants, and effective methods to remediate inorganic contaminants in fly ash.

This study investigated the leaching of a group of concerned inorganic contaminants from different types of fly ashes, and assessed the impact of trona inject for SO₂ emission control at coal combustion plants on the fly ash produced. The results showed that trona injection greatly changed the fly ash physical and chemical composition, and significantly enhanced the leaching characteristics of oxyanionic trace elements, especially arsenic (As) and selenium (Se). A protocol was developed to quantify the availability and stability of As and Se in raw bituminous fly ash under various field conditions. The effectiveness of EDT A-washing in remediating fly ash was studied, and the results demonstrated promising application of EDT A in removing toxic trace elements, including As and Se, from low-Ca coal fly ashes"--Abstract, page iv.


Wang, Jianmin

Committee Member(s)

Burken, Joel G. (Joel Gerard)
Morrison, Glenn
Wronkiewicz, David J.
Yang, John J.


Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering


Missouri University of Science and Technology

Publication Date


Journal article titles appearing in thesis/dissertation

  • Impact of Trona-Based SO₂ Control Technology on Fly Ash Leaching Characteristics
  • Understanding the Enhanced Arsenic and Selenium Leaching Behavior of Trona Ash Generated from an SO₂ Control Plant
  • Modeling Batch Leaching Behavior of Arsenic and Selenium from Raw Bituminous Coal Fly Ashes
  • Extraction of As and Se from coal fly ash using EDTA


xiii, 223 pages

Note about bibliography

Includes bibliographical references.


© 2011 Tingzhi Su, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Fly ash -- Environmental aspects
Leachate -- Environmental aspects

Thesis Number

T 10177

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