The textile industry’s most efficient processes for dyeing textiles require large amounts of water, energy and chemicals, and that’s a problem, now being addressed by University of Borås doctoral student May Kahoush.
Currently the industry tries to solve that problem by using enzymes to cause the degradation of dyes and other chemicals. For maximum functionality, the enzymes need to attach to the surface of a support material. Degradation is usually assisted by acids or oxidizing solutions at high temperatures for lengthy time periods. The result is that large amounts of energy are used, and water and large quantities of dangerous substances are released into the environment.
A recent article from the University of Borås explains that Kahoush’s goal was to purify the wastewater before it was emitted. She developed three methods, each of which reduces the consumption of water and energy as well as the amount of hazardous chemicals emissions. The challenge was how to attach the enzymes to a suitable material.
“We have used felted carbon fiber textiles, a common material used in many different applications, and using these textiles the enzymes can attach and help degrade the dye molecules. The carbon fiber textile is a porous, lightweight material that resists corrosion and that is easily formed, which can be used as an alternative to expensive, rigid metals. The carbon fiber also has good electrically conductive properties, which is a prerequisite for getting the desired properties in electrochemical applications,” she said.
One hurdle to success was the carbon fiber textile’s water repellent nature. Kahoush needed to pretreat the material so water could be absorbed and the enzymes could attach. To aid the adhesion of the enzymes, she used a substance from the gardenia flower; an environmentally friendly coating; and a cold plasma treatment. The first two methods require only small amounts of water and the plasma method needs neither water nor chemicals.
The enzymatic activity taking place on the carbon fiber material creates hydrogen peroxide, which breaks down dyes. This action, in turn, reduces emission of the dyes and other pollutants.
The article cites other advantages to Kahoush’s research on immobilizing the enzymes. The process is stable and the enzymes can be reused. The stable enzymes don’t run the risk of remaining on the dyed textiles and causing allergic reactions in wearers. And In addition to purifying water, the method may be used to identify substances enzymes react with, in this case to glucose, the article stated.
Source: University of Borås
Kahoush’s doctoral thesis: Eco-Technologies for Immobilizing Redox Enzymes on Conductive Textiles, for Sustainable Development. The project was implemented within Sustainable Management and Design in Textiles (SMDTex), a doctoral program within Erasmus Mundus on sustainable management and textile design.