The Dutch province of Friesland has made use of recycled toilet paper to pave a cycle path. The 1km stretch connecting the Frisian capital of Leeuwarden to the town of Stiens was laid last year and is reportedly withstanding wear and tear every bit as well as surrounding stretches.
Citylab reports that paper fibre is sifted out of waste water by a 0.35 millimetre industrial sieve. It then goes through a series of machines which clean, sterilise, bleach and dry it. You are left with what is known as tertiary cellulose.
“If you look at it, you would not expect it to have originated from wastewater,” said Chris Reijken, a wastewater treatment advisor at Waternet, a Netherlands water authority. “You can touch it, you can use it. It’s no problem.”
Dutch asphalt is porous to deal with heavy rainfall and this requires more bitumen in the mix. Tertiary cellulose can be added to thicken the mixture and keep the bitumen from dripping off the aggregate.
Water authorities can apparently pay 180 euros a ton to transport waste sludge to an incinerator, so there is great interest in actually making use of a portion of it.
“It’s a strange idea for people that there’s [toilet paper] in the road,” said Michiel Schrier, provincial governor of Friesland. “But when they cycle on it or feel it, they can see that it’s normal asphalt.”