Water2REturn (REcovery and REcycling of nutrients TURNing wasteWATER into added-value products for a circular economy in agriculture) was an Innovation Action co-funded by the European Commission under its Horizon 2020 programme. It focused on the recovery and recycling of nutrients from slaughterhouse wastewater as part of a circular economy model.

Under this model, nutrients recovered are turned into value added products for the agro-chemical industry and the agricultural sector. Water2REturn proposed a viable, cross-sectoral and integrated full-scale demonstration process to treat slaughterhouse wastewater by using a novel combination of biochemical and physical technologies and processes in cascade. The extracted nutrients can be injected back into the economy as new raw materials, thereby becoming a resource instead of a waste.

Water2REturn also promotes symbiosis between key industrial sectors (e.g. agriculture, food processing and wastewater treatment), reduces the environmental impacts of food production and improves the competitiveness of slaughterhouses. A prototype system will have a treatment capacity of 50 m3 per day, and will include a water line, a sludge line and an algae line.