Performance evaluation of two Aspergillus spp. for the decolourization of reactive dyes by bioaccumulation and biosorption

Abstract

A biological method was adopted to decolourize textile dyes, which is an economic and eco-friendly technology for textile wastewater remediation. Two fungal strains, i.e. Aspergillus lentulus and Aspergillus fumigatus, were used to study the removal of low to high concentrations (25 to 2000 mg L⁻¹) of reactive remazol red, reactive blue and reactive yellow dyes by biosorption and bioaccumulation. The biosorption was successful only at the lower concentrations. A. lentulus was capable of removing 67–85% of reactive dyes during bioaccumulation mode of treatment at 500 mg L⁻¹ dye concentration with an increased biomass uptake capacity. To cope up with the high dye concentration of 2000 mg L⁻¹, a novel combined approach was successful in case of A. lentulus, where almost 76% removal of reactive remazol red dye was observed during bioaccumulation followed by biosorption. The scanning electron microscopy also showed the accumulation of dye on the surface of fungal mycelium. The results signify the application of such robust fungal strains for the removal of high concentration of dyes in the textile wastewaters.