Plenty of ideas for even more circular residuals in the water sector

Chemicals, pipes and energy are needed for the treatment and transport of drinking water and wastewater. At the same time, these activities produce residuals and used pipes. Wouldn’t it be great to use these residuals to make new raw materials and products for reuse in the water sector?

There are already a few fine circular examples in the water sector, such as water softening with own calcite, arsenic removal with pellets from aquafer, or bank protection with separated sieve cellulose (EFGF). But many more opportunities remain. And we plan to grab them!

Energetic workshop

Last December we met with fifty people, from within and outside the water sector, to brainstorm the opportunities for the circular use of residuals and other ideas to make the water sector more circular. For inspirational purposes, we produced a Sankey diagram (see above illustration) for all individual participants and for the three main groups, namely: groundwater, surface water and wastewater. This super energetic workshop came up with no fewer than 170 ideas, which the sector can now get to work on. Rob Kragt of Desso/Tarkett inspired us all with the story of how Desso transformed itself from an old-fashioned carpet maker into a hip circular company. His message: ‘Go and do it! Just get out there and do it! You’ll see that if you harness all of your company’s powers of innovation, you can achieve a lot more than you think.’

We can’t make use of all the fruit from this rich harvest in AquaMinerals’ activities. We’re conveying a number of the opportunities and ideas to others, for instance, the Blauwe Netten purchasing network and the WiCE-Stowa Circular Water 2050 project.

We’re getting down to it

Last week, under the supervision of the P2 company, we worked in a second workshop on further elaborating the ‘Top 11 high-scoring projects’. These include: milk of lime from lime pellets from softening processes; bio-based polymer for dewatering; dewatering without polymer; carbon source from separated sieve product; bio-based pipes; and circular opportunities in new construction and renovation (see list below). We will try in the period ahead to get these projects in the starting blocks.

Ground-breakers and fresh ideas

During the course of the workshop it became apparent that there was a strong need for a joint vision and approach to make the water sector circular. Without such a big picture all the nice ideas and projects are no more than fragments. But this shouldn’t be a grey, mainstream ambition and vision. It has to be one that gives a free rein to ground-breakers and companies with fresh ideas. In any case, there certainly are enough ideas and enthusiasm!

(Work)Top 11 circular ideas

Milk of lime from calcite pellets. Replace caustic soda with milk of lime
Bio-based polymer, e.g., alginate or mussels
Dewatering without polymer, e.g., with brush centrifuge or heat  
Lime pellets to replace calcium carbonate (deacidification, remineralisation, etc.)
Carbon source (≠ activated carbon) from sludge/separated sieve product/screenings 
Web-shop for circular watercycle products + buyer catalogue with possibilities
Circular opportunities in new construction + renovation over the short term (sector approach)
Bio-based pipes ‘green pipes’
Remanufacturing plastic pipes into new pipes or relining
Biomass as raw material for bio-plastics (e.g., PE for pipes)
Energy and water savings through lower-pressure distribution network