Remoção do corante Azo Direct Black 22 utilizando fungos Aspergillus

Abstract

During the activity of the textile industrial sector, characteristic effluents are generated due to their strong coloration and, in contrast to the benefits, concerns arise from the impacts caused by the presence of dyes in the effluents. As they are difficult to degrade and have high toxicity, dyes lead to the eutrophication process and a reduction in the photosynthetic rate in water bodies, in addition to presenting toxic bioaccumulative potential. Therefore, it is essential to treat wastewater prior to release into water bodies, with the bioremediation process that employs micro-organisms to degrade such compounds as an alternative. Thus, this study aimed to investigate the ability of fungi of the genus Aspergillus to remove the tetra-azo dye Direct Black 22 (DB22). A selection of fungi from DB22 dye discoloration (50 mg/ L) was performed using 1g of live biomass of A. japonicus (URM 5620), A. niger (URM 5741) and A. niger (URM 5838) with duration 2 hours of experimentation, under at room temperature and 120 RPM. The fungi that showed the best results were A. niger (URM 5741) and A. niger (URM 5838), which in the initial 10 minutes of the experiment removed the DB22 dye by 86% and 97%, respectively. Such fungi were used with values of 1 g and 3 g of live biomass to evaluate the influence of the amount of biomass, since 1 g of biomass presented at the end of the test better dye removal, reaching the maximum discoloration of 100% and 99% for A. niger (URM 5741) and A. niger (URM 5838), respectively. The decolorizing capacity between live and dead fungal biomass (1 g) was also investigated, and it was observed that the dead biomass had the best percentage of discoloration, 66% and 96% for A. niger (URM 5741) and A. niger (URM 5838), respectively, still in the first minute of rehearsal. In this way, showing the ability of Aspergillus to remove DB22. Therefore, having seen the efficiency of application of such a filamentous fungus, it is necessary to further investigate the fungal biological mechanism in the removal of the textile dye and evaluate different test conditions to later be applied in real effluent on an industrial scale in order to contribute to the reuse of water in the harsh region of the State.