Polystyrene Reused to Filter Toxic Pollutants from Water

Researchers from Brazil and the UK have devised a method for reusing polystyrene to filter toxic and carcinogenic waste chemicals from water.

The researchers wanted to tackle the significant problem of water pollution in the form of solid plastics and waterborne chemicals. Currently, chemicals such as synthetic dyes continue to be released in industrial wastewater due to poor water treatment methods. 

Reusing waste to clean water

The method freezes waste polystyrene in a solution with cyclohexane (which has a freezing point of 6° C). When the solvent is removed, expanded polystyrene is left behind. The transformed material can then be coated with photocatalytic nanoparticles, creating a solid-state photocatalyst that can be introduced into contaminated waste water samples to break down dyes such as Rhodamine B. This particular dye is banned in food production but is widely used in sewage treatment plants to detect leaks.

The larger water pollution problem

The researchers point to a popular series "Blue Planet II" from the BBC which recently drew attention to the problem of plastic debris, referred to as white pollution. You can see a summary of the program's findings here.  It will really make you think twice about how you use, and dispose of, plastic bottles and other plastics. The researchers’ work will help take a bite out of white pollution by presenting a new use for the waste polystyrene and contributing to a safer, healthier aquatic environment.

To learn more about these scientists’ work, see their published findings in ACS Applied Materials & Interfaces.