Volume 19 (2017) Article 4

Biosorption of hexavalent chromium from aqueous solutions using highly characterised peats

by A.M. Rizzuti, C.R. Newkirk, K.A. Wilson, L.W. Cosme and A.D. Cohen

Published online: 08.02.2017

Summary

This research investigated the biosorption of hexavalent chromium (Cr^VI) from aqueous solutions by six highly characterised peats. Samples of the peats were tested both in unaltered condition and after being treated with hydrochloric acid (HCl) to free up any occupied exchange sites. Other variables tested were sample dose, contact time, mixing temperature, and the concentrations and pH of the Cr^VI solution. Desorption studies were also performed, and tests were done to determine whether the peats could be re-used for CrVI biosorption. The results indicate that all six peat types biosorb Cr^VI from aqueous solution well (42–100 % removal) and that their Cr^VI removal capacities are affected by manipulation of the various factors. The two factors that had the greatest impact on the CrVI removal capacities of the peats were the concentrations and pH of the CrVI solution. As the Cr^VI solution concentration and pH were increased, the percent of Cr^VI removed decreased dramatically (33–56 % decrease for concentration increase; 36–45 % decrease for pH increase with four of the six peat types). The desorption results indicate that it may be possible to recover up to 5 % of the removed Cr^VI. All of the peat types tested can be repeatedly re-used for additional Cr^VI biosorption cycles. Hence, their disposal should not become a hazardous waste problem.

Citation

Rizzuti, A.M., Newkirk, C.R., Wilson, K.A., Cosme, L.W. & Cohen, A.D. (2017): Biosorption of hexavalent chromium from aqueous solutions using highly characterised peats. Mires and Peat, 19(4), 1-10. (Online: http://www.mires-and-peat.net/pages/volumes/map19/map1904.php); 10.19189/MaP.2016.OMB.248

Reviewers

IMCG and IPS acknowledge the work of the reviewers.