Oxidative removal of arsenite by Fe(II)- and polyoxometalate (POM)-amended zero-valent aluminum (ZVAl) under oxic conditions

C.C. Wu; L.C. Hus; P.N. Chiang; J. C. Liu; W.H. Kuan; C.C. Chen; Y.M. Tzou; M.K. Wang; C.E. Hwang; J.C. Liu

doi:10.1016/j.watres.2013.02.024

Oxidative removal of arsenite by Fe(II)- and polyoxometalate (POM)-amended zero-valent aluminum (ZVAl) under oxic conditions

Journal

Water Research

Journal Volume

47

Journal Issue

7

Pages

2583-2591

Date Issued

2013-05

Date

2013-05

Author(s)

C.C. Wu

L.C. Hus

P.N. Chiang

J. C. Liu

W.H. Kuan

C.C. Chen

Y.M. Tzou

M.K. Wang

C.E. Hwang

DOI

10.1016/j.watres.2013.02.024

URI

https://scholars.tari.gov.tw/handle/123456789/14961

Abstract

Abiotic transformation of As(III) to As(V) is possible which would decrease As toxicity. This study investigated the potential applications of zero-valent Al (ZVAl) or Al wastes, such as Al beverage cans, for converting As(III) to As(V) in an acidic solution under aerobic conditions. Results showed that As(III) could not be oxidized by ZVAl within 150 min reaction at pH 1 because of the presence of an oxide layer on ZVAl. However, 85 μM As(III) could be completely oxidized with the addition of Fe(II) or POM due to the generation of a Fenton reaction or the enhancement of H2O2 production, respectively, on the ZVAl surfaces. Because Fe(II) or polyoxometalate (POM) exhibited more stable at low pH and scavenged rapidly the H2O2 produced on the aerated ZVAl surfaces, OH radical productions were more efficient and As(III) was rapidly oxidized in the ZVAl/O2 system with theses two catalysts. The catalytic oxidation kinetics of As(III) in the presence of Fe(II) or POM were best described by zero-order reaction, and the rate constants increased with a decrease of pH from 2 to 1. Following the oxidative conversion of As(III) to As(V) in the ZVAl/Fe/O2 system, As(V) was removed by the newly formed hydrous Al/Fe precipitates by increasing the solution pH to 6. Nonetheless, the As(V) removal was incomplete in the ZVAl/POM/O2 system because the hydrolyzed products of POM, e.g., View the MathML sourcePO43−, inhibited As(V) removal due to the competitive adsorption of the oxyanion on Al precipitates. Discarded Al-based beverage cans exhibit a higher efficiency for As(III) oxidation and final As removal compared with that of ZVAl, and thus, the potential application of Al beverage cans to scavenge As in solutions is feasible.

Subjects

Arsenic

Zero-valent aluminum

Ferrous ions

Polyoxometalate

Al beverage can waste

Publisher

Elsevier

Type

journal article

File(s)

Name

index.html

Size

22 KB

Format

HTML

Checksum

(MD5):eb616ad0e5af11d21476ca0d150f8e08