Biomass growth and dye removal efficiency
The growth of the fungal strain C. globosum IMA1was investigated
on an ITE using batch systems during 10 days of static and
stirred cultures. Results showed that the maximum dry weight of
mycelium of 6.22 g/L was measured in the stirred culture after 4
days of incubation (Fig. 4a) with a maximum specific growth rate
mmax of 0.14 g/g/h. However, without agitation C. globosum grew
slowly on ITE to give 5.2 g/L of mycelium after 6 days of incubation
(mmax ¼ 0.09 g/g/h). After that, a decrease of the mycelia biomass
concentrations to 4.9 g/L and 4.4 g/L was observed for stirred and
static cultures, respectively. The determination of growth yield
versus incubation time showed that mycelia grew during the first 4
days using organic dyes as a substrate. In fact, C. globosum is able to
grow on ITE and presents an appreciable agent for its pollutants
biodegradation.
The biodegradation process is essentially controlled by the pH of
the medium. The variation of pH values during the ITE treatment
process using C. globosum is presented in Fig. 4b. The pH values
increased from 5.5 to 7.9 and 6.2 after 24 h of incubation and
reached final values of 9.05 and 8.7 for stirred and static cultures,
respectively. The pH increase was followed by a rise of the decolourization
yields and CODs removal efficiencies (Fig. 4c and d). As
observed by Dirk et al. (2003), the fungus produces organic