Progesterone from contraceptive pills ends up in wastewater and then travels freely on into natural waters, as there is no technology to remove it from water. Progesterone affects fish by causing males to change into females.
VTT Technical Research Centre of Finland came up with the idea of combining a porous fibre thread with sugar, which is able to capture hormones from surrounding water. VTT is now studying the possibility of utilising this invention in wastewater treatment.
A thread made of wood fibre is appropriate for this purpose, because it is very porous and low in cost, but other pulp-based threads are equally suitable. The porous structure of the thread means that its specific surface area is large, which increases the potential to capture hormones. The wood-based thread can also be safely burned or composted after use.
The molecules used to capture the hormones are cyclodextrins, which consist of dextrins bound together in a ring. They are also able to capture other molecules found in pharmaceuticals.
The thread was developed as part of the project Design Driven World of Cellulose. After the project has ended, the development will be continued and the technology may be scaled up. Because the materials used are inexpensive and suited to the technology, obstacles to industrial production are unlikely.