Simultaneous hydrogen production and decolorization of denim textile wastewater: kinetics of decolorizing of indigo dye by bacterial and fungal strains

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 H 2 /L-d, achieving at the same time color removal. A total of thirtyfive 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.

A critical review of textile industry wastewater: green technologies for the removal of indigo dyes

“…6 ) dye, although the final products in both cases are anthranilic acid; this difference is due to the higher redox potential of fungal enzymes compared to that of bacterial enzymes (Legerská et al 2016 ). Aspergillus H1T showed a color removal of 96% in 48 h, which was significantly faster than Bacillus, Lysinibacillus, and Lactobacillus (Table 3 ) (Valdez-Vazquez et al 2020 ). …”

Biomaterials and Electroactive Bacteria for Biodegradable Electronics

“…This means that the orbitals which are not used in the intermolecular binding of the elements overlap and form conductive pathways. Despite having a high melting point, and low solubility, indigo can be degraded by enzymes ( Campos et al, 2001 ), bacteria ( Valdez-Vazquez et al, 2020 ), oxidizing agents ( Prado et al, 2008 ) and light (in water) in timeframes down to a single day ( Vautier et al, 2001 ), with a reported rate of 0.90 μmol L –1 min –1 ( Vautier et al, 2001 ). In donor-acceptor solar cells, indigo acts like a good acceptor material ( Glowacki et al, 2011 ).…”

Remediation of Brewery Wastewater and Reuse for β-Glucans Production by Basidiomycete Fungi

“…especially the white-rot fungi (WRF), once they perform an essential role in organic matter decomposition, assisting the nutrient exchange and recycling [9]. Basidiomycete fungi tend to degrade a vast number of contaminants [10][11][12][13], including the agricultural, industrial, and agrochemical [8,14], as well as assist the biological effluents treatment through enzymatic mechanisms and biotransformation [15][16][17].…”