CYCLODEXTRINS TO RECOVER TEXTILE DYES IN WASTE WATER

Abstract

Cyclodextrins are cyclic oligosaccharides with a special toroid shape, obtained by the action of glucosyltransferase enzyme (CGTase) on starch molecule. Their peculiar structure allows the accommodation of different guest molecules inside their cavity forming molecular inclusion complexes. There are different types depending on the glucose units that are formed, called native. The cyclodextrins can be modified incorporating different groups (hydroxipropyl, methyl...) that changes their properties. Due their versatility in size, properties and the variety of inclusion complex can form is employed in many different industries like pharmacy, food or cosmetics to protect the molecule or to reduce their volatility. As the guest molecule is not bond with the cyclodextrin with the appropriate conditions it can release easily. In textile industry had been use in different areas: to remove surfactants from washed textiles, to substitute surfactants, in the dyeing process, in detergents… Due their capacity to fix onto textile allows the functionalization of the fabrics giving them new properties like UV protection, antimicrobial or insect repellents depending on the guest molecule, in. The project DYES4EVER employs the cyclodextrins to encapsulate dyes not fixed during the dye process that remains in the wastewater and aims to go one step further and reuse the dyes recovered as a raw material in new dyeing processes.

Keywords

• Reuse
• Textile dyes
• cyclodextrins
• inclusion complex