Today water pollution has become a significant challenge for the environment and human health. Dyes cause serious water pollution in water resources and harm the environment and human health.
Researchers at North Carolina State University claim that a synthetic polymer can remove some dyes from water and that the polymer can be recovered and reused. The study, “Polycarbodiimide for Textile Dye Removal from Contaminated Water,” was published online in ACS Applied Polymer Materials. The results of the study suggest a new potential method for cleaning wastewater generated from textile, cosmetics, or other industries.
Januka Budhathoki-Uprety, lead author of a paper on the work and an assistant professor of textile engineering, chemistry and science at NC State said “Dyes are used everywhere, including in the textile industry, as well as in pharmaceuticals, cosmetics, paper, leather and even in medicines. If these contaminants aren’t properly removed from wastewater after dyeing and finishing, they can be a significant source of environmental pollution and pose risks for human health.”
In the study, the researchers created a synthetic polymer called polycarbodiimide and tested the material’s ability to clean wastewater by dissolving it in a solvent and then mixing it with water contaminated with dyes. They tested the polymer solution against a series of 20 anionic dyes (acid dyes) used in the textile industry. For an initial evaluation, the researchers performed a visual test with the naked eyes to see if the polymer worked. The researchers then measured how well the polymer removed the dye using UV-Vis spectroscopy.
“We mixed the polymer solution and dye-contaminated water so the polymer in the solution can grab onto the dye. This is a two-phase solution, just like oil and water. The polymer part of the solution grabs onto the dyes,” Budhathoki-Uprety said. “Then we were able to easily separate the clean water from the contaminated solution mixture by draining it out, similar to the separation of water from a mixture of oil and water.”
The polymer was successful to remove all but four of the 20 acid dyes they tested. In addition, they found that it was easy to recover the polymer within minutes. “We found that the polymer solution can remove dyes from contaminated water, and we can recover the polymer and use it to remove dye from contaminated water again,” Budhathoki-Uprety said.
For future studies, the researchers plan to create a library of polymers that will have the potential to work with more types of dyes. Additionally, they want to develop a more practical process for using polycarbodiimide to treat wastewater. A solid material such as dye spills are easier to handle compared to a flammable solution.