Influence of redox mediators and salinity level on the (bio)transformation of Direct Blue 71: kinetics aspects

The rate-limiting step of azo dye decolorization was elucidated by exploring the microbial reduction of a model quinone and the chemical decolorization by previously reduced quinone at different salinity conditions (2–8%). Microbial experiments were performed in batch with a marine consortium. The d...

Full description

Saved in:
Bibliographic Details
Published in:Journal of environmental management 2016-12, Vol.183, p.84-89
Main Authors: Alvarez, Luis H., Meza-Escalante, Edna R., Gortáres-Moroyoqui, Pablo, Morales, Luz, Rosas, Krystal, García-Reyes, Bernardo, García-González, Alicone
Format: Article
Language:English
Subjects:
Anthraquinones - metabolism
Azo Compounds - metabolism
Azo dyes
Chemical oceanography
Chemical reactions
Coloring Agents - metabolism
Humic Substances
Kinetics
Marine consortium
Microbiology
Organic chemistry
Oxidation-Reduction
Redox mediators
Riboflavin - metabolism
Salinity
Seawater - microbiology
Vitamin B
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The rate-limiting step of azo dye decolorization was elucidated by exploring the microbial reduction of a model quinone and the chemical decolorization by previously reduced quinone at different salinity conditions (2–8%). Microbial experiments were performed in batch with a marine consortium. The decolorization of Direct Blue 71 (DB71) by the marine consortium at 2% salinity, mediated with anthraquinone-2,6-disulfonate (AQDS), showed the highest rate of decolorization as compared with those obtained with riboflavin, and two samples of humic acids. Moreover, the incubations at different salinity conditions (0–8%) performed with AQDS showed that the highest rate of decolorization of DB71 by the marine consortium occurred at 2% and 4% salinity. In addition, the highest microbial reduction rate of AQDS occurred in incubations at 0%, 2%, and 4% of salinity. The chemical reduction of DB71 by reduced AQDS occurred in two stages and proceeded faster at 4% and 6% salinity. The results indicate that the rate-limiting step during azo decolorization was the microbial reduction of AQDS. [Display omitted] •A marine consortium uses humic substances as redox mediators for azo dye treatment.•Azo dye reduction was evaluated at different salt conditions using redox mediators.•The rate limiting step of azo dye reduction is the microbial reduction of AQDS.
ISSN:0301-4797
1095-8630
DOI:10.1016/j.jenvman.2016.08.044