Characterizing toxic Cr(VI) contamination in chromite mine overburden dump and its bacterial remediation

Dhal, B and Das, N N and Thatoi, Hruayanath and Pandey, B D (2013) Characterizing toxic Cr(VI) contamination in chromite mine overburden dump and its bacterial remediation. Journal of Hazardous Materials, 260 (IF-4.173). pp. 141-149.

[img]PDF
Restricted to NML users only. Others may use ->

2470Kb

Abstract

Cr(VI) generated due to natural oxidation of chromite mineral present in chromite mine overburden (COB) dumps of Sukinda, India, has been characterized by different physico-chemical methods. The Cr(VI) was found to be associated with goethite matrix at a contamination level of 500 mg Cr(VI) kg-1 of COB. Bacillus sp. isolated from the overburden sample exhibiting high tolerance to the hexavalent chromium, was used for the remediation of Cr(VI) in the overburden. The process was optimized while varying the parameters such as pH (2 – 9), pulp density (10 - 60%) and temperature (25–40 oC). Optimal reduction of more than 98% of Cr(VI) in the COB sample was achieved in 16 h at pH ~7.0 and 60% pulp density with the Bacillus sp. (4.05  107 cell mL-1) in absence of media. The exponential rate equation yielded rate constant value of 2.14 × 10-1 h-1 at 60% pulp density. The mode of bio-reduction of Cr(VI) in the overburden sample was established by FT-IR, XRD, EPMA and SEM-EDS studies.

Item Type:Article
Official URL/DOI:http://dx.doi.org/10.1016/j.jhazmat.2013.04.050
Uncontrolled Keywords:Chromite mine overburden; Bacillus sp.; Hexavalent chromium; Bio-reduction
Divisions:Metal Extraction and Forming
ID Code:6604
Deposited By:Mr Biswaranjan Dhal
Deposited On:15 May 2013 14:38
Last Modified:11 Jun 2013 17:49
Related URLs:

Repository Staff Only: item control page