Classified locality Yeasts have been culturing in plantology
department at the Faculty of Science-University of Damascus,
from genera of Pichia, Candida, Geotrichum, Rhodotorula, Phaffia
on solid Czhapek agar medium, and after incubated in appropr
iate
conditions their colonies showed evidence of different colors to
produce a variety of pigments. Then it cultured in liquid Czhapek
medium to increase biomass and the genera producing
endocellular pigment separated from the medium by filtration with
added ethanol on them and blasting cells by ultrasonic waves to
get a pigment, while the genera producing exocellular pigment is
separated about the liquid medium also by filtration but the solvent
was added to the medium containing the pigment.
During the past few years attention has been drawn on chemical techniques
that could be used to discolour textile wastewaters. We have studied the
photocatalytic degradation of various dyes (Methyl orange, Azo carmine B,
Coomassie Brilliant blue G
250, Tartrazine, Calcon, Eriochrome blue SE,
Solamine Red 4BL, Bismarck brown Y(G), Methylen blue, Black 5, Red 120,
Morin) using TiO2 P25 Degussa as catalyst. All dye solutions underwent a
decolourization. The kinetics of reaction have been studied and were found to
be zero or first order with respect to the dye. It was compared with the
adsorption properties. The effect of the addition of hydrogen peroxide has been
studied. An enhancement of the rate has been observed in all cases and the
order with respect to the dye's concentration in presence of the additive seemed
not to change. It is difficult to give general view of the kinetics using these very
different dyes but the process was found to be effective for the decolourization
of textile wastewater.
