Biodegradation of anthraquinone dye by Aspergillus niger SA1 in self designed fluidized bed bioreactor

ABSTRACT

Biodegradation and decolorization of Drimarene blue K2-RL [anthraquinone] dye by a fungal isolate Aspergillus niger SA1 was studied in self designed lab scale bioreactor system with different solid supports. Aspergillus niger SA1, was efficiently immobilized on sand and sodium alginate beads. The immobilized cells were used in the form of fluidized bed reactor for textile dye [Drimarene blue] removal. Both the reactors were operated at room temperature and pH=5.0 in continuous flow mode with increasing concentrations of dye in simulated textile effluent. The reactors were run on fill and draw mode, with hydraulic retention times of 24-72 h. The fluidized bed bioreactor with sand as immobilizing support [FBR1] showed overall better performance as compared to fluidized bed bioreactor with sodium alginate as immobilizing support [FBR2]. The average overall color, BOD and COD removal in the FBR1 system were up to 78.29, 70.81 and 83.07% respectively, with 50 ppm initial dye concentration and HRT of 24 h. While 72.19%, 86.63% and 74.74% removal of color, BOD and COD were observed, respectively, in FBR2 with the same conditions. Reductions in BOD and COD levels along with color removal proved that decolorization and biodegradation occurred simultaneously