Optimization Of Incubation Conditions Of Phanerochaete Chrysosporium And Its Decolorization Performance Of Azo Dye

Dye wastewater is an unmanageable organic pollution in the field of environment protection.Traditional wastewater-treating technologies have a very limited ability to treat dye wastewater.In the 1980s,it has been found that white rot fungi have a high ability in treating wastewater containing refractory organic pollutants,such as pesticide-wastewater,oiliness-wastewater, ammunition-wastewater,paper making-wastewater.Since then,the research of dye wastewater treatment by white rot fungi has been developing rapidly.However,because the incubation conditions of white rot fungi are so complicated,white rot fungi have not applied to practical dye wastewater treatment project yet.In order to improve the operability and stability of white rot fungi used in wastewater treatment,a part of the incubation conditions were optimized for white rot fungi growth,the MnP production,and decolorization of dye.In addition,the mechanism of optimization was studied exploringly.Finally,the decolorization of dye was investigated using white rot fungi Phanerochaete chrysosporium under the optimal incubation conditions.The main results were as follow:(1) The optimal incubation conditions for white rot fungi Phanerochaete chrysosporium growth and MnP production were screened out,i.e.the optimal phosphorus concentration in medium was 2.00 g/L,and the optimal immobilized carrier was polyurethane foam.(2) Too low or too high phosphorus concentration in medium was not propitious to producing MnP.When the phosphorus concentration was 2.00 g/L,the white rot fungi Phanerochaete chrysosporium produced more MnP(324.9U/L) which was 324,97,2,1.5 and 29 times of the 0.00 g/L,0.01 g/L,0.05 g/L,0.50 g/L and 4.00 g/L respectively.Within certain phosphorus concentration range,the biomass of white rot fungi Phanerochaete chrysosporium increased with phosphorus concentration.However,while phosphorus concentration beyond the threshold,the increasing extent of biomass with phosphorus concentrations would reduce gradually.(3) The MnP excreted by white rot fungi Phanerochaete chrysosporium immobilized in polyurethane foam was the highest(915.62 U/L),which was 15,25,2 and 4 times of the fiberglass net,stainless steel net,nylon net and suspended culture system,respectively.Under the optimal incubation conditions,the peak of MnP production was also ahead 2～5 d than suspended culture and immobilization culture with other carriers.(4) The alveolate structure of the optimal carrier polyurethane foam is able to provide greater surface area and extended space for white rot fungi,which result in enhancing the transfer efficiency of nutrients and oxygen in the system.(5) Under the optimal incubation conditions,the decolorization of reactive dye K-2BP was more than 95%,higher than the suspended system,and the decolorization time was ahead 3 days than suspended system. (6) Under the optimal incubation conditions,the consumption rates of carbon and nitrogen in medium were faster than the suspended system.And the production of H₂O₂ by white rot fungi also was higher than suspended system,in addition,the biomass of white rot fungi was influenced weakly by dye than suspended system.