Degradation of a leather-dye by the combination of depolymerised wood-chip biochar adsorption and solid-state fermentation with Trametes villosa SCS-10

• Published in: Bioresources and bioprocessing Vol. 7; no. 1
• Main Authors: Ortiz-Monsalve, S., Gutterres, M., Valente, P., Plácido, J., Bustamante-López, S., Kelly, D., Kelly, S. L.
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01-12-2020; Springer Nature B.V
• Subjects: Adsorption; Biochemical Engineering; Charcoal; Chemical properties; Chemistry; Chemistry and Materials Science; Depolymerization; Design optimization; Dyes; Efficiency; Environmental Engineering/Biotechnology; Fermentation; Functional groups; Industrial and Production Engineering; Laccase; Leather; Malt; Nutrients; Peptone; Peptones; Pore size; Porosity; Potassium permanganate; Response surface methodology; Sodium hydroxide; Solid state; Solid state fermentation; Sorbents; Surface chemistry; Adsorption and biodegradation; Solid-state fermentation; Mycoremediation; Leather-dyes; Biomass; Biochar; White-rot fungi
• ISSN: 2197-4365; 2197-4365
• DOI: 10.1186/s40643-020-00349-z

Adsorption into biochar-derived materials and mycoremediation are promising technologies for removing dyes from solid and liquid matrices. This study presents a combined treatment with adsorption into wood-chip biochar and mycodegradation under solid-state fermentation by
Trametes villosa
for removing the leather-dye Acid Blue 161. In the first stage, untreated wood-chip biochar, NaOH–depolymerised biochar and KMnO
4
–depolymerised biochar were assessed for their dye removal efficiency by adsorption. KMnO
4
–depolymerised biochar exhibited the highest adsorption (85.1 ± 1.9%) after 24 h of contact. KMnO
4
–depolymerisation modified some physical and chemical properties on the untreated wood-chip biochar, increasing the surface area (50.4 m
2
 g
–1
), pore size (1.9 nm), and presence of surface functional groups. Response surface methodology coupled with a Box–Behnken design was used to optimise the AB
161
adsorption into the KMnO
4
–depolymerised biochar. The optimised conditions, pH 3.0, dye concentration 100 mg L
–1
and sorbent dosage 2 g L
–1
, led to a higher dye removal efficiency by adsorption (91.9 ± 1.0%). In a second stage, the wood-chip biochar supplemented with nutrients (1% malt extract and 0.5% peptone) was employed as a solid matrix for growing
T. villosa
and regenerating the dye-saturated material. After 15 days,
T. villosa
was able to grow (86.8 ± 0.8%), exhibit laccase activity (621.9 ± 62.3 U L
–1
), and biodegrade (91.4 ± 1.3%) the dye adsorbed into the KMnO
4
–depolymerised biochar. Finally, the mycoregenerated biochar was reutilised in a new cycle of adsorption reaching 79.5 ± 2.0% of dye removal efficiency by adsorption. This study revealed the potential of the combined treatment and is an initial assessment for developing commercial alternatives for treating leather industry wastewaters.