Research On Decolorization Of Refractory Dyes By Mixed Culture Of Anti-nutritional-Repression White Rot Fungi

This paper conducted the experimental study on the decoloration effect of refractory dye by mixed cultivating two kinds of white rot fungi-phanerochaete chrysosporium and Trametes versicolor.Firstly,screening and optimizing the impact factors and cultivation ways on dye decoloration by single factor optimization and orthogonal experiments.Further,studying about the ability on dye repetitive decoloration and the limit of dye concentration of mixed cultivation system was conducted.Then,study the decoloration effect through the simulation of mixed white rot fungi on the real dye decolorization condition.Finally,we determinate the influences of heavy metal ions(cadmium,chromium and lead)press on growth,enzyme production and effect of dye decolorization about mixed cultivation white rot fungus.Through experimental researches,the conclusions of this paper as follows:1.Phanerochaete chrysosporium 553,Trametes versicolor CFCC-4 and mixed fungus(mixture ratio =1:1)were used to decolore three kinds of single refractory reactive dyes(reactive brilliant yellow K-6G,reactive brilliant blue KN-R,reactive brilliant red KD-8G).Phanerochaete chrysosporium 553 obtained a better decoloration dye than Trametes versicolor CFCC-4,in addition the mixed cultivation white rot fungi got the superior effect on dye decoloration,as well as its growth and enzyme production comparing with the two signal fungie.2.After optimizing the mixed white rot fungi,the best decoloration conditions for reactive brilliant red KD-8 B were:the biomass proportion of Pc553 with CFCC-4 was 1:3 and inoculating simultaneously,mixed cultivation time was 8 days and cultivation temperature at 36 ?.For the reactive brilliant blue KN-R,the best decoloration conditions were:the biomass proporation was 1:7,inoculating Trametes versicolor CFCC-4 first and then inoculating Phanerochaete Chrysosporium Pc553,mixed cultivation time was 8 days,cultivation temperature at 32 ?.While,For the reactive brilliant yellow K-6G,the best conditions were:the biomass proporation was 1:3,inoculating Trametes versicolor CFCC-4 first and then inoculating Phanerochaete Chrysosporium Pc553,mixed cultivation time was 10 days,cultivation temperature at 36 ?.3.The highest concentration of mixed white rot fungi on dyes degration for reactive yellow K-6G,reactive brilliant blue KN-R and reactive brilliant red KD-8B were 150 mg/L,400 mg/L and 200 mg/L,respectively.In addition,the mixed white rot fungi could repetitive declolore four batches on the dyes that the concentration was 50 mg/L,while adding 1 g/L of maltose to keep white rot fungi vitality and prolonging the time of each batch decoloration.4.Under the traditional experimental method,mixed white rot fungi can efficient degradate the concentration of compounding dyes as high as 250 mg/L.To simulate actual decolorization conditions,the decolorization rate of compounding dyes declined obviously by compounding dyes.The decolorization rate were 93%,82%,64%,20%,8%when the final volume of the compounding dyes and mixed white rot fungi were 100 mL,300 mL,500 mL,700 mL,900 mL.5.Based on the study on the mixed white rot fungi of heavy metal ions(cadmium,chromium and lead)pressing on dyes decoloration,the results indicated that low concentration of heavy metal ions had no significant effects on the growth and enzyme production of mixed white rot fungi,even had stimulation effects.However,excessive concentration of heavy metal ions leaded to toxicity,thus restriction the growth and enzyme production of the mixed white rot fungi,as well as its dyes decoloration effect.The toxicity to the mixed white rot fungi were Cd2+>Cr6+>Pb2+.