Process optimization for effective bio-decolourization of reactive orange 16 using chemometric methods

Area of Science:

• Environmental Microbiology
• Bioremediation
• Industrial Biotechnology

Background:

• Azo dyes, like Reactive Orange 16 (RO16), are widely used in textile and tannery industries, posing environmental challenges.
• Chromate (Cr(VI)) is a toxic heavy metal often found alongside dye pollutants in industrial wastewater.
• Effective bioremediation strategies are needed to address complex industrial effluent pollution.

Purpose of the Study:

• To investigate the decolorization of Reactive Orange 16 (RO16) dye using the bacterium Pseudomonas aeruginosa 23N1.
• To assess the simultaneous removal of chromate (Cr(VI)) and RO16 dye.
• To optimize the process conditions for efficient dye decolorization and Cr(VI) removal.

Main Methods:

• Screening of operational parameters using a two-level factorial design.
• Optimization of conditions using Response Surface Methodology (RSM) with Central Composite Design (CCD).
• Microbial decolorization experiments using Pseudomonas aeruginosa 23N1 in various culture media.

Main Results:

• Pseudomonas aeruginosa 23N1 achieved over 95% decolorization of RO16 dye at concentrations of 50 mg/L and 150 mg/L.
• Yeast extract supplemented medium without external carbon sources favored high decolorization rates.
• Dye decolorization was negatively impacted by high chromate (Cr(VI)) concentrations (>120 mg/L).

Conclusions:

• Pseudomonas aeruginosa 23N1 is a promising biological agent for the effective decolorization of RO16 dye.
• The bacterium demonstrates satisfactory performance in treating RO16-contaminated industrial wastewater.
• Simultaneous removal of dye and Cr(VI) is feasible, though high Cr(VI) levels can inhibit decolorization.