Chromate reduction on humic acid derived from a peat soil - Exploration of the activated sites on HAs for chromate removal
Journal
Chemosphere
Journal Volume
87
Journal Issue
6
Start Page
587
End Page
594
ISSN
00456535
Date Issued
2012-05
Author(s)
Huang, S. W.
Liu, Jen Chyi
Hung, Juiting
Kuan, Wenhui
Tzou, Yuming Min
Huang, Janghung
Chen, Chungchi
Wang, Mingkuang
Loeppert, Richard H.
Abstract
Humic substances are a major component of soil organic matter that influence the behavior and fate of heavy metals such as Cr(VI), a toxic and carcinogenic element. In the study, a repetitive extraction technique was used to fractionate humic acids (HAs) from a peat soil into three fractions (denoted as F1, F2, and F3), and the relative importance of O-containing aromatic and aliphatic domains in humic substances for scavenging Cr(VI) was addressed at pH 1. Spectroscopic analyses indicated that the concentrations of aromatic C and O-containing functional groups decreased with a progressive extraction as follows: F1>F2>F3. Cr(VI) removal by HA proceeded slowly, but it was enhanced when light was applied due to the production of efficient reductants, such as cal and H2O2, for Cr(VI). Higher aromatic- and O-containing F1 fraction exhibited a greater efficiency for Cr(VI) reduction (with a removal rate of ca. 2.89mmolg-1 HA under illumination for 3h). 13C NMR and FTIR spectra further demonstrated that the carboxyl groups were primarily responsible for Cr(VI) reduction. This study implied the mobility and fate of Cr(VI) would be greatly inhibited in the environments containing such organic groups.
Subjects
Aromatic groups
Cr(VI)
Humic acid
Oxygen-containing c
Reduction
SDGs
Publisher
Elsevier Ltd
Type
journal article