Biological treatment of textile effluent in stirred tank bioreactor

A fungal isolate Aspergillus terreus SA3 previously isolated from the waste water of a local textile industry was efficiently utilized for the removal of dye (Sulfur black) from textile effluent. The treatment was performed in a self-designed lab. scale stirred tank bioreactor. The reactor with 5 L capacity (working volume 2 L) were operated at room temperature and pH 5.0 in continuous flow mode with different dye concentrations (50, 100, 150, 200, 300 & 500 ppm) in simulated textile effluent (STE). The reactors were run on fill, react, settle and draw mode with hydraulic retention time (HRT) of 24-72 h, depending upon the concentration of dye. Overall color, BOD and COD in the Stirred tank reactor system (STR) were removed by 84.53, 66.50 and 75.24%, respectively with 50 ppm dye concentration and HRT of 24 h. The removal efficiency of the reactor decreased as the concentration of the dye was increased. This STR system was found very effec tive for efficient treatment of textile wastewater (up to 200 ppm Sulfur black dye) by the fungal strain A. terreus SA3.