Researchers develop and test Re-plex, a circular and bio-based building material sourced from cellulose found in wastewater.

Amsterdam’s population alone flushes approximately 33L of water per person per day. Among what goes down the toilet per year across the Netherlands includes mountains of cellulose-rich toilet paper. How can this discarded paper be upcycled into environmentally-friendly building materials?

A waste-free Amsterdam 
Currently, the large flows of waste urban areas discharge are not optimally recycled. As resources are ultimately finite, there is a growing urge to recycle waste-streams in an urban context. Amsterdam is mapping various material flows, from entry to processing, in order to preserve precious raw materials. The city’s aim is to halve the use of new raw materials by 2030 to become a fully circular city by 2050. COMPRO investigates how organic materials from wastewater can make useful building materials that contribute to these goals.  

Biological processes convert urban organic waste-streams 
Two important waste streams can be found in wastewater: cellulose-fibers from retrieved toilet paper and a biological glue called Kaumera. This glue is produced by bacteria in the wastewater treatment process. 

A bio-based, circular building material 
Together, these create a waste-based, bio-based, and circular composite building material.  Students identified 41 applications for Re-plex, including roof support structures, fire-resistant panels, structures for plant growing, temporary pavement, and more. 

A circular resource management model 
Producing this novel material consumes 88% less energy than traditional composites, such as polyester glass fibers. COMPRO addresses the greater urban challenge of transitioning from a linear to a circular model of resource management in the Amsterdam Metropolitan Area (AMA). The consortium developing Re-plex tested its durability for six months at the Bajeskwartier test bed for sustainable innovations. [PD: have you got news on the outcome of the test?]  

Afbeelding credits

Header afbeelding: Flickr - waste water