Simultaneous hydrogen production and decolorization of denim textile wastewater: kinetics of decolorizing of indigo dye by bacterial and fungal strains.
Braz J Microbiol 2020;
51:701-709. [PMID:
32319044 DOI:
10.1007/s42770-019-00157-4]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 09/09/2019] [Indexed: 10/24/2022] Open
Abstract
This study proposes the treatment and valorization of denim textile effluents through a fermentative hydrogen production process. Also, the study presents the decolorizing capabilities of bacterial and fungal isolates obtained from the fermented textile effluents. The maximum hydrogen production rate was 0.23 L H2/L-d, achieving at the same time color removal. A total of thirty-five bacteria and one fungal isolate were obtained from the fermented effluents and screened for their abilities to decolorize indigo dye, used as a model molecule. From them, isolates identified as Bacillus BT5, Bacillus BT9, Lactobacillus BT20, Lysinibacillus BT32, and Aspergillus H1T showed notable decolorizing capacities. Lactobacillus BT20 reached 90% of decolorization using glucose as co-substrate after 11 days of incubation producing colorless metabolites. Bacillus BT9 was able to utilize the indigo dye as the sole carbon source achieving a maximum decolorization of 60% after 9 days of incubation and producing a red-colored metabolite. In contrast, Bacillus BT5 and Lysinibacillus BT32 exhibited the lowest percentages of decolorization, barely 33% after 16 and 11 days of incubation, respectively. When Aspergillus H1T was grown in indigo dye supplemented with glucose, 96% of decolorization was reached after 2 days. This study demonstrates the valorization of denim textile effluents for the production of hydrogen via dark fermentation with concomitant color removal.
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