3. Results and discussion
Screening of C. versicolor IBL-04 on different effluents showed
different decolorization capability of the fungus for effluents collected
from different industries. The best decolorization (36.3% in 6
days) was noted for ART effluent followed by CRT (28.7% in 6 days),
ITT (28.6% in 10 days), MGT (13% in 10 days) and AST (6.99% in 6
days) industry effluents (Fig. 1). The slight changes in final pH were
noted in all flasks. The initial pH of all decolorization media was 4.5
and it remained fairly constant with the exception of CRT that rose
to almost pH 9.0.
All the dying units were using mixtures of disperse and direct
dyes (some of them also using reactive dyes) imparting different
colors and color intensities to the discharged effluents. The variable
composition of effluents along with change in dye structures
present in each effluent may be responsible for varying degree of
decolorization caused by C. versicolor IBL-04. The ease of some dye
structures to be decolorized by WRF as compared with others may
also be responsible for these results [10,27]. The extremely poor
results for densely colored effluents from MGT and AST industries
may be accounted for higher unused dye concentrations that may
inhibit C. versicolor IBL-04 growth. Dyes, being toxic compounds are
well tolerated and best decolorized at lower concentrations