Wood-based yarn collects EE2 from wastewater

The Technical Research Centre of Finland (VTT) and Aalto University have developed a wood-based cellulose fibre yarn that is an affordable solution for capturing pharmaceutical substances – especially ethinylestradiol (EE2) in contraceptive pills – that would otherwise end up in bodies of water, said an official press release.

“Hormone capture would be most effective in wastewater treatment plants and hospitals, since the wastewater in these facilities contains a higher concentration of the compounds. We are developing a wood-based affordable material that could be thrown into a tank in a wastewater treatment plant or used as a filter in a pipe connected to the tank. After some time, the material is collected mechanically. It is disposed of by incineration, but it is also possible to separate the pharmaceuticals and reuse the material,” said VTT’s Senior Scientist Hannes Orelma.

By attaching a cyclic sugar onto the surface of the cellulose fibre yarn, the research scientists were able to create a material that efficiently captures ethinylestradiol.

The cyclic sugars are bonded chemically onto the surface of the yarn. The sugars form a pocket into which hydrophobic pharmaceutical substances seek to enter.

This way, it only takes a few minutes for pharmaceutical compounds to become bound to the cyclodextrins coupled to the surfaces and cavities of the fibre. Test results demonstrate that one gram of fibre yarn can capture approximately 2.5 milligrams of the hormone.

The development effort used wood-pulp-based fibre yarn that was manufactured using deep eutectic solvents (DES) in a method developed by VTT. DESes represent a new generation of organic solvents, some of which can be environmentally very friendly. This research used an environmentally friendly DES.

“It would be interesting to test how effectively the cellulose yarns can capture hormones and pharmaceuticals from wastewater at a larger scale,” Orelma said.