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Note: This article is from Conservation Magazine, the precursor to Anthropocene Magazine. The full 14-year Conservation Magazine archive is now available here.

Dye Out

December 11, 2013

Fique plant fibers vanquish toxic dyes

Near textile factories in China and India, rivers run pink, purple, and blue. They’re contaminated with clothing dyes dumped into waterways instead of being sent to treatment plants. “You can find out what color is in fashion in New York by looking at the water in those areas,” says Juan Hinestroza, a fiber scientist at Cornell University in Ithaca, New York.

The dyes don’t just make rivers look odd. These colored chemicals prevent light from penetrating the water to reach plants and aquatic organisms. Some are toxic and don’t break down easily.

Researchers at the Universidad Industrial de Santander in Colombia, collaborating with Hinestroza, believe the native Latin American fique plant could help address the problem. The plant’s fibers are used to make sacks, including bags for shipping coffee beans.

The fibers are unique in that they contain tiny compartments. The researchers had already found that the compartments could aid the synthesis of nanoparticles by providing a contained space in which to grow the particles to a controlled size. For example, they were able to synthesize bacteria-killing nanoparticles inside these cavities. Since some nanoparticles are highly reactive, the team wondered whether nanoparticle-studded fique fibers could degrade dyes as well.

Since manganese compounds are known to break down molecules, the authors synthesized manganese oxide nanoparticles in the fique fiber compartments. Then they dipped the treated fibers into indigo carmine, a blue dye used in jeans. Within five minutes, the nanoparticles degraded the dye and turned the water clear, the team reports in Green Chemistry. Next, the researchers hope to create mesh filters made of fique fibers that can clean up textile-plant effluent.

—Roberta Kwok

Chacón-Patiñom M.L. et al. 2013. Biocomposite of nanostructured MnO2 and fique fibers for efficient dye degradation. Green Chemistry doi:10.1039/c3gc40911b.

Photo courtesy Cornell University

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