Residues from the healthcare sector often end up in waters due to the inability of current water treatment plants to filter out hormones and other pharmaceutical substances. VTT began tackling the problem in 2015 in a project entitled ‘Design Driven Value Chains in the World of Cellulose II (DWoC)’ with Aalto University.
“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,” explained Hannes Orelma, senior scientist at VTT, in a release.
“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.”
The yarn was produced with deep eutectic solvents using VTT’s novel, and now patented, method. Coated with cyclic sugars, the yarn is able to capture substances into its sockets when it swells up in water. In the laboratory tests, the yarn was able to capture roughly 2.5 times its own weight in ethinylestradiol, a hormone used in contraceptives.
“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.”