Quantifying the Availability and the Stability of Trace Cationic Elements in Fly Ash

Abstract

For adsorption-desorption controlled leaching processes, the total leachable mass and the adsorption constant are parameters representing the availability and the stability of trace elements in solid media. with these parameters, one can predict the leaching behavior of trace elements from solids under various pH and solid-to-liquid ratio conditions. an approach was developed in this paper to determine these parameters for model elements Cu(II), Cd(II), and Ni(II) in fly ash. This approach consists of a batch equilibrium titration, a batch equilibrium leaching with and without target element addition, and mathematical modeling. Results indicated that the adsorption constant of a trace element can be determined by modeling the adsorption ratio of the added element to the system as a function of pH. Results also indicated that the trace element originally present in fly ash had similar adsorption-desorption behavior as that added externally. by modeling the batch leaching data with and without external element addition, the total leachable mass and adsorption constant of the target element can be determined simultaneously. the total leachable mass is in agreement with experimental data from 50 mM EDTA extraction.

Department(s)

Civil, Architectural and Environmental Engineering

Sponsor(s)

Electric Power Research Institution

Keywords and Phrases

Leaching

International Standard Serial Number (ISSN)

0956-053X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2007 Elsevier, All rights reserved.

Publication Date

01 Jan 2007

Link to Full Text

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