Use of Multivariate Experimental Designs for Optimizing the Reductive Degradation of an Azo Dye in the Presence of Redox Mediators

Abstract

The optimization of the anaerobic degradation of the azo dye Remazol golden yellow RNL was performed according to multivariate experimental designs: a 2 2 full-factorial design and a central composite design (CCD). The CCD revealed that the best incubation conditions (90% color removal) for the degradation of the azo dye (50 mg L -1 ) were achieved with 350 mg L -1 of yeast extract and 45 mL of anaerobic supernatant (free cell extract) produced from the incubation of 650 mg L -1 of anaerobic microorganisms and 250 mg L -1 of glucose. A first-order kinetics model best fit the experimental data (k = 0.0837 h -1 , R 2 = 0.9263).

Degradation of Synthetic Azo Dyes of Textile Industry: a Sustainable Approach Using Microbial Enzymes

“…Occasionally, under unfavorable environment, some usual cellular enzymes may also get converted into dye-degrading enzymes, for example, at times, flavin reductase from E. coli acts as azoreductase [27] Dye-contaminated soil sample Metanil yellow (sulfonated azo dye) [45,49] Pseudomonas putida mt-2 -Acid Violet 7 [41] and uses FADH as a redox mediator. As bacteria use azo dye as their sole carbon or nitrogen sources, they can also make product from glucose [29] (Fig. 2).…”