Sponge Material Clears Colour from Dye-Contaminated Water

The new porous and reusable material, which is made from cellulose and palladium metal, works with reducing agents to help remove colour almost instantly. The large pores allow water to flow through easily, while the metal particles act as a catalyst. Existing reducing agents for chemical dyes can turn coloured dyes clear, but are slow-working and often inefficient.

Dyes are widely used in industries such as textiles, cosmetics, paper and plastics. After manufacturing, a large amount of effluent can bypass wastewater treatments, contaminating water for aquatic plants and animals. Even a small amount of colour dye can block out sunlight, preventing photosynthesis and damaging the aquatic ecosystem.

The team’s method of turning a coloured dye clear would allow plants to grow normally again. "This method could work well when you have low concentrations of dye in water that you need to take care of really quickly,” said one of the team members. For another dye-degrading technique, see Scientific Dye Developments in Considered Colour.

Last year, a lab in the US developed a material called Oleo Sponge that soaks up oil from water. The team have since conducted a successful experiment in real-world conditions that mimicked an oil spill. Read more about the material in our blog. 

For more on water sustainability, see Water Futures: Designing Sustainable Systems and Water: Sustaining Supplies.