TITLE:
A Review on Cr(VI) Adsorption Using Inorganic Materials
AUTHORS:
Claudia Rosales-Landeros, Carlos Eduardo Barrera-Díaz, Bryan Bilyeu, Víctor Varela Guerrero, Fernando Ureña Núñez
KEYWORDS:
Sorption; Hexavalent Chromium; Clay; Silica; Zeolites
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.7A,
July
2,
2013
ABSTRACT:
Chromium compounds are widely used in electroplating, metal finishing,
magnetic tapes, pigments, leather tanning, wood protection and electronic and
electrical equipment. Hexavalent chromium is a highly toxic metal and produces
health damages. The most soluble, mobile and toxic forms of hexavalent chromium
in soils are chromate and dichromate
and the chromium distribution is also controlled by redox processes, its
adsorption decreases with increasing pH and when competing dissolved anions are
present. Several techniques have been developed to remove Cr(VI) from
wastewater but these techniques have disadvantages such as high cost,
non-selective, pH dependence,
etc. The use of low cost sorbents has been investigated as a replacement for
current costly methods; natural materials with a high adsorption capacity for heavy metals can be obtained.
Modification of the sorbents can improve adsorption capacity. This paper
includes some techniques for remove Cr(VI) with clays, silica and zeolites from
aqueous solutions, some of the treated adsorbents show good adsorption
capacities.