Application of Aspergillus niger SA1 for the enhanced bioremoval of azo dyes in Simulated Textile Effluent

Abstract

Biological remediation is always envisaged as cost effective and eco-friendly for the treatment of recalcitrant dyes and effluents.

Aspergillus niger SA1, a brown rot fungi, isolated from storage pond of textile wastewater, showed a great mineralizing ability for azo dyes, acid red (AR) 151 and orange (Or) II. Decolorization assays were carried out for 24 h, by taking 100 ml of dye containing Simulated Textile Effluent (STE) with 5 g of freshly grown fungal pellets. Decolorization of AR 151 was well over 95% under different conditions, however, it reduced to 52% when treated with pre-used fungal biomass under shaking condition. In case of Or II, results were 50 and 61% under static while 65 and 85% under shaking condition with fresh and pre-used fungal biomass respectively. Primarily, dyes removal in STE appeared due to biosorption/bioadsorption of the fungal biomass. However, discoloration of dyes onto the biomass with subsequent formation and then decline in their products in STE suggested clearly that dyes were basically metabolically degraded by the fungal strain.