Study On Immobilization Of Phanerochaete Chrysosporium For Decolorization Of Acid Black ATT

Acid Black ATT is a typical compound azo dye,which has the characteristics of poor biodegradability, high chroma, complex composition, and it will cause great pollution when it is directly discharged to the environment. Therefore, the decolorization treatment of Acid Black ATT becomes a key link in the treatment of such wastewater.At present,there are few reports on the treatment of wastewater from the type ofdye-contaminated wastewater. In this paper, the immobilization technology was combined with the biological treatment of white rot fungi, and the Acid Black ATT was decolorized by immobilized white rot fungi in the manner of adsorption and embedding.Substance of the Acid Black ATT solution afterdecolorization was detected by gas chromatography-mass spectrometry (GC-MS) firstly, and changes in material structure that may be present after degradation are analyzed and compared.The results showed that the decolorization of Acid Black ATT by white rot fungi was not only due to the biosorption of microorganisms, but also to the cleavage of the chromophore N = N structure.In the adsorption immobilization experiments, free white rot fungi were respectively immobilized by adsorption on the modified plant material,such as sunflower calathide,sunflower stalk, sunflower seed coat, corncob and peanut hull. Then putting it into Acid Black ATT dye wastewater to decolorize. And the mechanical strength, adsorption,desorption and cell attachment of each blank carrier were compared. In this experiment.different carrier, temperature, shaking speed, initial pH of dyestuff wastewater,concentration of dye wastewater and other factors were investigated on the decolorization rate of Acid Black ATT. The results indicate that decolorization effect for Acid Black ATT of white rot fungus immobilized by sunflower calathide and sunflower stalks is better.Optimum conditions of decolorization of Acid Black ATT for the immobilized white rot fungus in sunflower calathide is pH 5.0, temperature 30℃, rotation speed 150rpm and initial dye concentration 100ppm. Optimum conditions of decolorization of Acid Black ATT for the immobilized white rot fungus in sunflower stalk is pH 5.0, temperature 22℃,rotation speed 150rpm and initial dye concentration 100ppm.The decolorization rate of Acid Black ATT was 94.41%and 90.49% under the optimum condition. The decolorization rate of Acid Black ATT can be maintained above 87% by these two carriers under the optimum conditions for 5 times.In embeddingimmobilization experiments, the white rot fungi wasimmobilized by sodium alginate (SA), polyvinyl alcohol (PVA) and activated carbon.The ratio of sodium alginate (SA) and polyvinyl alcohol (PVA) was adjusted by the immobilization effect,hardness and elasticity of immobilized pellets. And then the effects of different curing time and culture time on decolorization of Acid Black ATT wastewater were investigated.The results showed that the immobilized pellets had the best performance when the embedding immobilization ratio was 1%: 7%. The curing time and incubation time were 90 h and 5 d,respectively. At this time, the decolorization rate of the immobilized beads on acid black ATT was 78.13%.The mechanical strength, thermal stability, swelling rate, specific surface area, pore size distribution, pore volume and mass transfer of immobilized pellets were measured.The results show that the strength coefficient of the immobilized pellets can reach 93%, and the tolerable temperature of up to 85℃ .The expansion rate of immobilized beads was 1.459.The specific surface area was 27.73 m2 / g, the pore volume was 0.0533 cm3/g, and the average pore diameter was 19.11 nm.The mass transfer performance of immobilized beads was 99.46% under this immobilization method.The immobilized microspheres had dense pores under scanning electron microscopy.In the process of decolorization of Acid Black ATT with embedding immobilized white rot fungi, the effects of different carrier, temperature, shaking speed, initial pH and concentration of dye wastewater on the decolorization of Acid Black ATT were investigated.The results showed that the optimum conditions of decolorization of Acid Black ATT for the embedding immobilized white rot fungus in sunflower calathide is pH 3.5, temperature 30℃, rotation speed 150rpm and initial dye concentration 150ppm.Under these conditions, the decolorization rate of Acid Black ATT was 8 times and the maximum decolorization rate was about 81%, which provided a theoretical basis for the decolorization of dye wastewater by immobilized white rot fungi.In this paper,a large number of experiments confirmed that the immobilized white rot fungi on the complex azo dye wastewater has a good decolorization effect,Which has a good application prospect for the actual wastewater treatment.