The International Water Association’s prestigious Resource Recovery Best Practice Award 2015 has been awarded jointly to Waternet, Restoffenunie and industrial companies Ardagh Glass and Desso, for their inspired work on recycling calcium carbonate from wastewater for use in three industrial processes.

Summarising the decision Professor Willy Verstraete, Chair of the Resource Recovery Best Practice Award, said, “A flash of genius has transformed the calcium carbonate found in wastewater from a grey slurry to a marvelous crystalline product that has not just one, but three applications, in tonnages that are at industrial scale and under effective market conditions. This ‘second hand chalk’ adds significant value to all three applications.”

Across the world, practices to soften water are used to make perfect drinking water. The side stream of calcium carbonate which this process often generates is normally considered to be ‘worthless’, a ‘waste’ material with no or even negative value. The combined efforts of Dutch water treatment company, Waternet, and a company focused on recycling, Restoffenunie, has now effectively recycled these calcium carbonate wastes.

The three creative transformations that the Waternet- Restoffenunie partnership is credited with developing are:

• Waternet: Calcite pellets are recovered from Waternet’s water treatment process and recycled as seed material in the softening of drinking water. Changing from a traditional sand core to a calcite core in their softening pellets delivered cost savings, an improved environmental footprint and higher revenues;

• Desso: Calcite is used for the backing in carpet tiles. Desso worked with Restoffenunie and water companies to sole the biggest challenge of producing a suitable material at a competitive price. The cost of the dried and ground calcite is higher than what Desso previously paid but with this new product they save on bitumen costs due to better packing.

• Ardagh Glass: Calcite recovered from wastewater is used to produce glass. To be effective, calcite must have very low moisture content and low iron content. Ardagh Glass worked with Restoffenunie and Waternet to change to sand-free, lower iron content calcite seeding material, and to develop an environmentally friendly process for drying the pellets using a sepcially designed truck to lower moisture content using only the engine heat while in transit;

“This particular solution, replacing 7000 tonnes of limestone with calcite grains,  required thorough development and testing from our engineering team to maximise the benefits, and our sister plants are now looking carefully at how they can adopt the technology.” Says Sven-Roger Kahl, Manager, Glass Technology, Ardagh Glass, Europe. “Our close cooperation with Restoffenunie, a collective shared service centre of the Dutch Water Supply Companies, who provided valuable assistance throughout the process, was very beneficial.”

Professor Verstraete commented, “Innovation on resource recovery in the water cycle has been developing fast, but examples of large scale and marketable applications from current scientific innovations are scarce. Restoffenunie, Waternet, Desso and Ardagh Glass have made that leap. This award recognizes the importance of that.”

Partnered with the KWR Watercycle Research Institute in the Netherlands, the 2015 IWA Resource Recovery Best Practice Award was judged by an international evaluation committee chaired by Professor Willy Verstraete, of the University of Ghent. The award is made for a proven technology on resource recovery, applied at full or demonstrative scale in the water cycle, which can serve as an excellent example for the water sector.

Recovering resources from water and wastewater can provide an alternative and economically viable source of resources supporting the resilience of human and natural systems under water stress. Resources from the water cycle can be water itself, energy (organic or thermal) and components such as nutrients and metals.

A key issue in resource recovery is how to move from research to practice, while also taking into account the market potential for the resource recovered; appropriate public policy, regulation and institutional arrangements to support and accelerate resource recovery; and the needs of stakeholders integrated with technologies, markets, policy, new initiatives, and current research and practice.

The Award was made at the IWA Resource Recovery Cluster Conference 2015, during which the newly published Resource Recovery Compendium was launched. The Compendium is a state of the art report giving water professionals an overview on available technologies for resource recovery, as well as outline obstacles and opportunities for recovering resources from water in terms of technical, social, economic and political aspects. Read or download the Resource Recovery Compendium here.

The IWA Resource Recovery Cluster promotes resource recovery from water and wastewater, and connects different stakeholders and complementary organisations to find ways to build value chains. For more information on the cluster, please visit the cluster webpage.