Quantifying Effects of pH and Surface Loading on Arsenic Adsorption on Nanoactive Alumina Using a Speciation-Based Model

Abstract

Arsenic (As) poses a significant water quality problem and challenge for the environmental engineers and scientists throughout the world. Batch tests were carried out in this study to investigate the adsorption of As(V) on NanoActive alumina. The arsenate adsorption envelopes on NanoActive alumina exhibited broad adsorption maxima when the initial As(V) loading was less than a 50 mg g−1 sorbent. As the initial As(V) loading increased to 50 mg g−1 sorbent, a distinct adsorption maximum was observed at pH 3.2-4.6. FTIR spectra revealed that only monodentate complexes were formed upon the adsorption of arsenate on NanoActive alumina over the entire pH range and arsenic loading conditions examined in this study. A speciation-based adsorption model was developed to describe arsenate adsorption on NanoActive alumina and it could simulate arsenate adsorption very well in a broad pH range of 1-10, and a wide arsenic loading range of 0.5-50 mg g−1 adsorbent. Only four adjustable parameters, including three adsorption constants, were included in this model. This model offers a substantial improvement over existing models in accuracy and simplification in quantifying pH and surface loading effects on arsenic adsorption.

Department(s)

Civil, Architectural and Environmental Engineering

Sponsor(s)

Harbin Institute of Technology. Development Program for Outstanding Young Teachers
Harbin Institute of Technology. Natural Scientific Research Innovation Foundation

Keywords and Phrases

FTIR; Alumina; Speciation-Based Model; Adsorption; Arsenic; Fourier transform infrared spectroscopy

International Standard Serial Number (ISSN)

0304-3894

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2009 Elsevier, All rights reserved.

Publication Date

01 Jul 2009

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