TITLE:
Removal of Cr (VI) from Tannery Effluent and Aqueous Solution by Sequential Treatment with Microfungi and Basidiomycete-Degraded Sawdust
AUTHORS:
Bernard O. Ejechi, Olubunmi O. Akpomie
KEYWORDS:
Chromium, Tannery Effluent, Gloeophyllum, Aspergillus, Penicillium, Sawdust
JOURNAL NAME:
Journal of Environmental Protection,
Vol.7 No.6,
May
11,
2016
ABSTRACT: Removal of
Cr (VI) from aqueous solution and tannery effluent in sequence with Cr (VI)
resistant microfungi (Aspergillus niger, Penicillium chrysogenum) and sawdust
degraded by basidiomycete (Gloeophyllum sepiarium) was investigated in the
laboratory. Initial or primary treatment with microfungi reduced 200 mg/l Cr
(VI) in aqueous solution by 64.6% - 78.2% while a markedly lower 0.52 mg/l Cr
(VI) in tannery effluent was reduced by 72.4% - 84.6%. However, the residual Cr
(VI) in both aqueous solution and tannery effluent was reduced to a
non-detectable level after secondary treatment by passage through
basidiomycete-degraded sawdust column. The recovery of 65.4% - 87.7% of the Cr
(VI) removed by treatment microfungi by elution indicated adsorption as the
major mechanism for Cr (VI) removal. The microfungi reduced BOD in tannery
effluent by 85.3 ± 5.6 - 92.7 ± 6.8 and concomitantly removed Cr (VI), hence it
is hypothesized that non-Cr (VI) constituents of tannery effluent may have
interfered with biosorption of Cr (VI) by treatment microfungi. It is concluded
that the two-stage sequential treatment process may be of potential cost-saving
stratagem for removal of chromium from industrial wastes.