Bioremediation efficiency of free and immobilized form of Aspergillus niger and Aspergillus tubigenesis biomass on tannery effluent

Abstract

Untreated tannery effluent discharge, which causes severe environmental pollution. This research was performed to assess the bioremediation (multi-pollutant adsorption) potential of pre-identified and multi metal tolerant Aspergillus niger and Aspergillus tubigenesis through a stirred tank bioreactor in free and immobilized form. Physicochemical property analysis results showed that most of the tannery effluent properties were beyond the permissible limits. These A. niger and A. tubigenesis effectively immobilized on corncob and coir solid support material. The stirred tank bioreactor based bioremediation study revealed that the fungal biomass (Aspergillus niger and Aspergillus tubigenesis) immobilized coir and corncob material demonstrated remarkable multi-pollutant (TSS: 22.5% & 13.5%, TS: 29% & 22%, BOD: 21% & 10%, TDS: 28% & 19%, COD: 30% & 22%, Cr: 27% & 19%, Cu: 28% & 12%, and Pb: 48% & 29% respectively) adsorption potential in a week of treatment. Moreover, it reduced the toxicity of tannery effluent and promotes the sprouting of Oriza sativa seeds, as demonstrated by petri plate bioassay. These finding suggest that the metal-tolerant fungal isolates A. niger and A. tubigenesis demonstrated impressive bioremediation proficiencies in an immobilized state. A field investigation is required to assess the feasibility of this strategy on tannery effluent.