Quaternized Wood as Solvent
Applied Biochemistry and Biotechnology Vol. 90, 2001
Copyright © 2001 by Humana Press Inc.
All rights of any nature whatsoever reserved.
*Author to whom all correspondence and reprint requests should be addressed.
as Sorbent for Hexavalent Chromium
Chemistry Department, Faculty of Science and Environmental Studies,
Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia,
Received December 3, 1999; Revised July 19, 2000;
Accepted August 3, 2000
The potential of quaternized wood (QW) chips in removing hexavalent
chromium from synthetic solution and chrome waste under both batch and
continuous-flow conditions was investigated. Sorption was found to be
dependent on pH, metal concentration, and temperature. QW chips provide
higher sorption capacity and wider pH range compared with untreated wood
chips. The equilibrium data could be fitted into the Langmuir isotherm
model, and maximum sorption capacities were calculated to be 27.03 and
25.77 mg/g in synthetic chromate solution and chrome waste, respectively.
The presence of sulfate in high concentration appeared to suppress the uptake
of chromium by QW chips. Column studies showed that bed depth influ-
enced the breakthrough time greatly whereas flow rate of influent had little
effect on its sorption on the column.
Index Entries: Wood; chemical modification; biosorption; hexavalent
Many industrial activities, including iron and steel manufacturing,
chrome leather tanning, chromium plating, textile dyeing, and wood pres-
ervation, contribute to the increase in chromium in aquatic and terrestrial
ecosystems. This has caused great concern because chromium, especially in
its hexavalent form, is highly toxic. It is carcinogenic, mutagenic, and in
cells induces the formation of reactive oxygen species that damage cellular