Rubber granulate made from end-of-life car tyres may in future lend itself to applications such as wastewater treatment, say researchers.
A Finnish team has demonstrated that the granulate processed from used car tyres is capable of acting as biofilter material in sewage treatment.
The project, carried out by Finnish Tyre Recycling Ltd and Apila Group Oy at Heinola sewage works, showed that tyre rubber granulate is capable of effectively removing nitrogen and phosphorus from wastewater.
The granulate offers a large surface area for the biofilm to grow on and significantly retains, in particular, phosphorus, thanks to the iron contained in the granulate.
"No leaching of harmful substances from the tyre granulate to the soil or water was detected, but the use of granulate for sewage treatment requires an environmental permit," explained Risto Tuominen, managing director of Finnish Tyre Recycling.
"We have also decided to test tyre granulate in the treatment of industrial wastewater. Other interesting applications include the treatment of run-off water from agriculture, peat production and forestry," added Tuominen.
There is a lot of potential in tyre rubber granulate as soon as the hesitation to use it dissipates, said specialist Sanni Pisto from Apila Group.
