Biological Decolorization Techniques for Textile Wastewater

Biological decolourisation of textile effluents harnesses the metabolic capacity of microorganisms and their enzymes to transform or immobilise synthetic dyes, offering a sustainable alternative to physico-chemical treatments. Key approaches include biosorption onto microbial biomass, enzymatic degradation by oxidoreductases and peroxidases, and synergistic action within microbial consortia. Fungal mycoremediation exploits high extracellular enzyme production, while bacterial and yeast systems can operate under aerobic or anaerobic conditions. Extremophiles, such as alkaliphiles and halophiles, extend the operational envelope to high pH and salinity. Immobilisation of cells or enzymes on carriers enhances stability and recyclability, and packed-bed or fluidised-bed bioreactors permit continuous treatment. Process parameters—pH, temperature, dye concentration and nutrient availability—influence decolourisation efficiency. Advances in molecular tools and omics are identifying novel strains and pathways, enabling tailored consortia design. Collectively, these techniques demonstrate high removal efficiencies, low energy demand and minimal secondary pollution, underscoring their global significance for textile wastewater management and resource-efficient water reuse.

Research from Nature Portfolio

Recent studies have demonstrated the promise of a halotolerant yeast, Sterigmatomyces halophilus SSA1575, in treating Reactive Black 5 under high salinity. Optimised conditions yielded complete decolourisation within 18–24 hours, driven by NADH-dichlorophenol indophenol reductase and lignin peroxidase activities. Key process enhancements included tailored carbon and nitrogen supplementation and sequential dye additions. Comprehensive ecotoxicological assays confirmed detoxification of by-products, highlighting the strain’s potential for integration into saline textile effluent treatment systems.

Biological Decolorization Techniques for Textile Wastewater publication trend

The graph below shows the total number of articles in biological decolorization techniques for textile wastewater across all publications each year (not limited to Nature Index journals).

Technical terms

Azoreductase: Flavin-dependent enzyme catalysing reductive cleavage of azo bonds in dye molecules.

Laccase: Copper-containing oxidase that oxidises phenolic and non-phenolic substrates, facilitating dye breakdown.

Microbial consortium: Defined assembly of microorganisms whose combined metabolic activities enhance decolourisation.

Biosorption: Passive adsorption of dye molecules onto cell surfaces, concentrating pollutants for enzymatic attack.

Immobilisation: Fixation of cells or enzymes onto solid supports to improve operational stability and reuse.

References

1. Ecofriendly biodegradation of Reactive Black 5 by newly isolated Sterigmatomyces halophilus SSA1575, valued for textile azo dye wastewater processing and detoxification. Scientific Reports (2020).
2. Decolourization of azo Lanasyn Navy M-DNL dye by Trichothecium roseum toward green mycoremediation. npj Clean Water (2023).
3. A review of dye biodegradation in textile wastewater, challenges due to wastewater characteristics, and the potential of alkaliphiles. Journal of Hazardous Materials Advances (2024).
4. Biological Degradation of the Azo Dye Basic Orange 2 by Escherichia coli: A Sustainable and Ecofriendly Approach for the Treatment of Textile Wastewater. Water (2022).