Removal of Indigo Dye in Denim Plant Wastewater by CO2-Capturing Macroalgae

The indigo used in dyeing jeans is difficult to remove from the wastewater due to the recalcitrant nature of the dye. Meanwhile, current physiochemical decolouring treatment are high energy-consuming and involves uses of chemical additives. Therefore, wastewater treatment of denim dyeing is considered key to maintaining the sustainability of the textile industry.

• This project demonstrates a biological posttreatment method to remove indigo blue in wastewater from denim factories by using sunlight and macroalgae species.
• The dye in wastewater is broken down to isatin and then simpler compounds by the enzymes produced during the metabolism of the specific macroalgae species for dye biodegradation. Once the chemical structure of indigo dye is broken down, no further decolourisation is needed.

• As a pure biological decolourisation treatment that involves low infrastructure cost while being an effective solution for the reduction of wastewater dye pollutants and its threat to marine ecosystem, it thus contributes towards a sustainable denim manufacturing

• Silver Medal in the Special Edition 2022 Inventions Geneva Evaluation Days

• Relieving indigo dye pollution to marine ecosystem

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