RESUMO
Decolourization of wastewater from a textile plant by a marine Aspergillus niger was studied. The fungus was previously isolated from Gorgan Bay in the Caspian Sea. The kinetics of decolourization was studied by varying energy sources. The best decolourization was achieved when sucrose was used as source of carbon and energy. NH4+ ion was demonstrated to be the best nitrogen source. Color reduction was found to increase from 80-97% as inoculum concentration increased from 0.04-1.0 g/L. A minimum inoculum of 0.2 g/L is necessary to achieve decolourization. The optimal temperature for the growth of A. niger on Baftkar wastewater is found to be 30 degrees C. 90-96% colour reduction is achieved in 19-20 hr of contact of mycelium cell with the wastewater. Colour reduction in a continuous column reactor of 70% was obtained using treated mycelium (NaOH, 90 degrees C) after 1 hr.