The biosorption of Congo red azo dye by fungus Mucor circinelloides and its application in the decolorization of textile industry wastewater

The extensive application of dyes in the textile industries and their discharge in the wastewaters leads to numerous environmental pollutions; therefore, treating these wastewaters by efficient and eco-friendly methods is a necessity. In this study, potent strains were isolated by the enrichment technique according to their maximum dye sorption at the lowest possible time at 500nm. Consequently, the best isolate was selected and the dye removal was investigated in different concentrations of Congo red. Therefore, 50 different fungal strains were isolated in this study, of which 10 were able to dye removal. According to the results, isolate ADH8 was selected as the best strain with 94% of dye sorption. Moreover, during 48 hours, 80% of dye content was removed at all dye concentrations by this isolate, and the most growth rate and dye removal was achieved at 1000 mg/l. The results showed that different salt concentrations have no effect on dye sorption of the selected isolate. Molecular identification of ADH8 revealed that this isolate have a 100% similarity to Mucor circinelloides which was deposited under the accession number of UTMC 5032 in the University of Tehran Microorganisms Collection. The results obtained from the dye removal of textile wastewater showed that the most amount of dye sorption by M. circinelloides UTMC 5032 was 35-60% during three hours of biomass treatment as compared with the control sample. The obtained results indicated that, M. circinelloides UTMC 5032 is highly capable in azo dyes sorption and could be utilized in the biosorption of dye in the textile industries wastewaters for the first time.