Decolorization Of Reactive Birlliant Blue KN-R By Aspergillus Ficuum

The wastewater from dye and printing industries, leading to serious pollution, whichis one of the most difficult purified sewage. In order to improve the decoloring efficiencyof wastewater, many scholars focused on the enhancing biological techniques forwastewater purification. Accordingly, the key technique is that to screen high efficientstrain and to immobilize this organism. In this study, a superior strain, Aspergillus ficuum,was screened from the sludge of printing and dyeing plant with a selected medium.Decolorization of Reactive Brilliant Blue KN-R was studied by mycelial pellets of A.ficuum and immobilized cells, respectively. This study lays a foundation for furtherresearch and application of immobilization of high efficiency dye-decolorizing fungi.The results were presented as following:(1) The optimized conditions of decoloring with pellets were: cultural for 72h,temperature at 33℃, agitation rate at 150r/min, pH at 6.0, the concentration of salt at0.5%, lactose for carbon source, NaNO₃ for nitrogen source. The nutrition conditionsand concentration of salt affected the decolorization rate. In addition, the decolorizationrate reached 85.7% even though the mycelial pellets be reused four times.(2) The optimal preparation conditions of the strain immobilization on alginate wereobtained by the orthogonal test. They were sodium alginate 3%, CaCl₂ 5%, wet mycelia30g/L, calcific time 8h. It was found that the immobilized cells decolorized ReactiveBrilliant Blue KN-R effectively, the optimum temperature and pH were 33℃and 5.0respectively. The kinetics study of decolorization of immobilized cells showed that thedecolorization conformed to zero-order reaction model. The immobilized cells werereused after decolorizing for three times and the decolorization rate still reached 86.4%.(3) The decolorization of Reactive Brilliant Blue KN-R was also studied byimmobilizing fungus on Luffa cylindrical sponge. The best conditions of decolorizationrate were 3-day-old age culture, pH6.0 and 33℃respectively. The biomass of myceliaaffected the decolorization rate. The decolorization of A. ficuum followed thesecond-order reaction model. The decolorization rate still reached 80.8% after theimmobilized mycelia were reused for six times. (4) In the optimized conditions, the decolorization tests of wastewater from differentfactories were carded out with the pellets of A. ficuum and the immobilized cells. Theresults showed that all the decolorization rates were more than 60%, and that thedecolorization rate with pellets of A. ficuum in the form of immobilized Luffa cylindricalsponge was 80%.