Modeling Batch Leaching Behavior of Arsenic and Selenium from Bituminous Coal Fly Ashes

Abstract

Correctly predicting the leaching potential of arsenic (As) and selenium (Se) is critical for assessing the environmental impact of coal fly ash. This study investigated the impacts of several key environmental factors, including pH, leaching time, and ash washing on the batch leaching behavior of as and Se from bituminous coal fly ashes. the experimental results demonstrated that as and Se leaching from fly ash increased beyond the minimal leaching pH ranges. Increasing leaching time increased as leaching but decreased Se leaching in the alkaline pH condition. a speciation-Based adsorption model was used to quantify the batch leaching data, and determine the intrinsic leaching parameters including the total batch leachable mass and the adsorption constant of as or Se. the modeling approach was validated by correctly predicting the independent batch leaching data in a broad pH range and a different L/S condition. Experimental and modeling results also demonstrated that ash washing and ash aging (longer leaching time) did not change the adsorption constants of as and Se on the ash surface. However, ash washing could increase the availability of as and Se for leaching. © 2011 Elsevier Ltd.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

U.S. Department of Transportation, Grant None

Keywords and Phrases

Arsenic; Bituminous coal fly ash; Leaching; Selenium; Speciation-based adsorption model

International Standard Serial Number (ISSN)

1879-1298; 0045-6535

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier, All rights reserved.

Publication Date

01 Jan 2011

PubMed ID

21880348

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