Abstract
In the present study, the effects of various quinone compounds on the decolorization rates of azo dyes by the E. coli strain CD-2 were investigated. The results showed that Lawsone was the most effective redox mediator. The optimum concentration for Lawsone is 0.1 mmol/L. The effects of physic-chemical parameters on the Methyl Orange degradation by the strain were determined. The results indicated that, in the quinone mediated decolorization system, strain CD-2 exhibited a good degradation ability in the range of pH from 4 to 9, temperature from 20°C to 50°C and salinity from 1% to 6%. With Lawsone as a redox mediator, a broad spectrum of azo dyes with different structures could be decolorized by the strain. All the results showed that the addition of a redox mediator can be valuable for treating dye-colored wastewaters.
Highlights
Azo dyes, which characterized by one or more azo bonds, have been widely used in textile, food, cosmetics, paper printing and other industries [1] [2]
Strain CD-2 was tested for its ability to decolorize Methyl Orange under anaerobic
The results demonstrated that the addition of quinoid redox mediators significantly increased the rate of decolorization of Methyl Orange under anaerobic conditions, and compared with other mediators, Lawsone was a more effective mediator
Summary
Azo dyes, which characterized by one or more azo bonds, have been widely used in textile, food, cosmetics, paper printing and other industries [1] [2]. During production and application, about ten percent to fifteen percent untreated dyes discharge into environments with industrial effluents [3]. The characters of azo dye wastewater are high chroma, high concentration organics and high complicated components. Some azo dyes and their intermediate metabolites may cause cancer, malformation and mutation which seriously endanger the health of humans and animals [4]. The different technologies have been developed for the effective treatment of azo dyes before emission.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
