4.5 Article

Kinetics of the reduction of chromium(VI) by vitamin C

Journal

ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
Volume 24, Issue 6, Pages 1310-1314

Publisher

WILEY
DOI: 10.1897/04-238R.1

Keywords

reduction; hexavalent chromium; trivalent chromium; vitamin C

Ask authors/readers for more resources

The kinetics of the reduction of Cr(VI) to Cr(III) by vitamin C was studied using potassium dichromate solution as the model pollutant. Effects of the concentration of vitamin C, pH, temperature, and irradiation on the reduction of Cr(VI) were examined. The kinetics of Cr(VI) reduction by vitamin C can be described as -d[Cr(VI)]/dt = 0.0156 (mu M s(-1)).[Cr(VI)] [vitamin C] (pH 5), where dt is the differential function (d) of time (t). The activation entropy (Delta S-double dagger) and enthalpy (Delta H-double dagger) are 42.4 kJ mol(-1) and -71.0 J mol(-1) K-1, respectively, and the activation energy at 298 K is 63.5 kJ mol(-1). The advantages of vitamin C as a reductant are as follows: It is an important biological reductant in humans and animals, and it is not toxic. Toxic Cr(VI) can be reduced by vitamin C not only in acidic conditions but also in alkaline solutions (pH 9); furthermore, the reduction was shown to occur both under the irradiation and in the dark. The present results suggest that vitamin C could be used effectively in the remediation of Cr(VI)-contaminated soil and groundwater in a wide range of pH, with or without sunlight.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.5
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available