The treatment of textile waste water was conducted by using biological aerobic process. The design features of bioreactors may be categorized on the basis of mass transfer aspects and the mechanical aspects of bioreactor. The differences in geometric dimension attributes often result in dissimilar mass transfer, shear dynamics and mixing inside the bioreactor, that lead to disparities in cell growth. Experiments to evaluate the mass transfer characteristics were conducted to determine the nutrient requirements of the culture. The aim is to study the kLa of the bioreactor of different scales which is used as a main parameter for scaling up of cell culture process. The fungal used for the studies are Asperigillus Terrus and Asperigillus fumigates which are isolated from the textile waste sludge. The results of these characterization studies were used to define the scale up strategy for process.