Study on the decolourisation conditions of methylene blue by Irpex Lacteus

Abstract

The fungus Irpex Lacteus is effective in decolourising methylene blue, a common dye in printing and dyeing wastewater, and it is of clear significance to investigate its optimal decolourisation process through liquid fermentation. The medium mixed with methylene blue dye was incubated with Irpex Lacteus in a constant temperature shaking flask liquid fermentation equipment, and single factors such as incubation time, temperature, shaking bed speed, dye concentration, pH, carbon and nitrogen sources were screened, and key factors were targeted orthogonal tests were carried out to optimise the best decolourisation process for Irpex Lacteus against methylene blue. The single-factor test revealed that carbon, nitrogen, pH and inoculum were the main factors influencing the decolourisation of methylene blue by Irpex Lacteus. The results of the orthogonal test showed that the decolourisation effect was best when the carbon source was sucrose, the nitrogen source was peptone, pH=3.5, the inoculum level was 7% and the incubation time was 10 days. Irpex Lacteus showed good decolourisation effect on methylene blue and the optimised process conditions provided a new direction for the treatment of printing and dyeing wastewater.