Resource-oriented solutions for wastewater treatment based on a circular economy approach

Nowadays, water scarcity and resource recovery are global concerns. Therefore, there is rising demand for alternative and sustainable solutions to use water in the best possible way and to recover resources from going to waste. These solutions become a must when dealing with industrial sectors like slaughtering, a water-intensive industry that generates wastewater containing a high proportion of organic matter. This wastewater can be a valuable source of nutrients if properly recovered.
Furthermore, many products of current use are manufactured by using chemicals as a basis, when other options much more environmentally friendly are possible. Chemical fertilisers, for example, constitute a huge industry worldwide, although their extensive use represents a potential danger if they leach into water bodies, that can get polluted and suffer eutrophication, among other environmental problems.

So…why not making use of industrial symbiosis by turning wastewater treatment facilities in slaughterhouses into bio-refineries, following the Circular Economy principles? Addressing water scarcity while simultaneously recovering valuable resources is what Water2REturn sets out to achieve in a real case study: “Matadero del Sur”, a slaughterhouse in Salteras, Seville province, Andalusia region, Spain. Andalusia is a region well known for the challenges it faces in terms of water scarcity, what makes “Matadero del Sur” an ideal place to test the Water2REturn technology and an exemplar for other slaughterhouses all over Europe.


Water2REturn brings together 15 multidisciplinary actors from 8 different European countries – 9 SMEs, 2 European associations, 1 research centre and 3 universities – to implement an integrated solution for slaughterhouse wastewater treatment, as well as for the recovery of nutrients with high market value in the
agricultural sector.


Water2REturn is built on a bottom-up approach based on a current market demand. It constitutes a real technological breakthrough conceived to recover and recycle nutrients from slaughterhouse wastewater in the framework of a Circular Economy model. Nutrients recovered are turned into value added products for the agro-chemical industry and, consequently, for the agricultural sector, that seeks more sustainable products fulfilling the increasingly restrictive legislation requirements. At the same time, slaughterhouses solve their wastewater management problems, and reduced costs related to water consumption.


Water2REturn proposes a viable, cross-sectoral and integrated full-scale demonstration process by using a novel combination of biochemical and physical technologies and processes in cascade, all while aiming for a positive balance in terms of energy footprint –biological aeration systems, membrane technologies, anaerobic processes for bio-methane production and algal technologies, all combined in a zero-waste- emission system, with an integrated monitoring control tool that improves the nutrient flow data quality – . An environmental, economic, social and risk assessment of the technology performance and the products obtained will be also performed.


Water2REturn commercial outcomes will be: - An integrated system to treat wastewater while recovering nutrients, customisable according to the needs of the end user. - 3 raw materials: nitrate and phosphate concentrate, hydrolysed sludge and algal biomass, the basis for further manufacturing agronomic products. - 3 agronomic products: 1 organic fertiliser and 2 biostimulants, ready to be commercialised.


Water2REturn also aims to create new business opportunities and green jobs based on nutrient recovery and recycling, as well as to promote wide and fast market uptake of Water2REturn processes and products by implementing targeted business plans, and to improve their acceptance through capacity building and awareness


Water2REturn is an Innovation Action co-funded by the European Commission under its Horizon 2020 programme. It was submitted under the call “Industry 2020 in the Circular Economy” (call identifier H2020-IND- CE-2016- 17), topic “Water in the context of the circular economy” (topic identifier CIRC-02- 2016-2017). The objective of this topic was to implement large scale demonstration projects to tap the potential of nutrient recovery and to encourage the use of these nutrients throughout Europe, including the active participation of the relevant industrial sectors, as well as SMEs.



Demonstrator implementation at real scale

Development of a demonstrative application for slaughterhouse wastewater treatment and large-scale nutrient recovery in a real case study, the slaughterhouse “Matadero del Sur” in Salteras (Spain).


Fertilisers and biostimulants manufacturing

Manufacturing of organic-source fertilisers and biostimulants in production lines built up within Water2REturn project timeframe. They will be manufactured in Spain and tested in Slovenia, Romania, Lithuania and Spain.


Reduction of the environmental adverse effects of nutrient emissions and wastewater discharge

Nutrients recovery rates of 90-95 % (N and P) and reduction of wastewater discharged to the environment by 90%, thus decreasing water bodies pollution and other related environmental problems. Moreover, the treated water obtained can be further used, reducing operational costs of the slaughterhouse.


Reduction of landfilled waste

Reduction of waste diverted to landfills by 80%. After removing the organic elements from the slaughterhouse wastewater, the remaining inorganic fraction (less than 20% of the wastewater composition) will be the only residual element taken to landfills.


Energy self-sufficiency of slaughterhouses wastewater treatment plants

Biogas upgrading and valorisation will allow achieving self-sufficiency rates and savings of up to 25% in the slaughterhouse, with the consequent reduction of CO 2 and greenhouse gas emissions.


Promotion of a wide and fast market uptake of Water2REturn processes and products

Targeted business plans will be implemented with the aim of creating new business opportunities and green jobs around nutrient recovery and recycling technologies, especially for SMEs in EU. The acceptance of the final commercial outcomes by final users will be enhanced through capacity building and awareness raising.


Decrease of the dependency on primary nutrient resources

Decrease of the dependency on primary nutrient resources and increasing the supply security at EU level.

Reduction of the adverse effects of nutrient emissions

Reduction of the adverse effects of nutrient emissions on water bodies.

Closing of water and nutrients’ cycles

Closing of water and nutrients’ cycles in the whole production and consumption value chain.

Obtain high quality data of the nutrient flow

Obtain high quality data of the nutrient flow to optimize the recuperation of valuable nutrients.

Creation of new green jobs, industries and business opportunities

Creation of new green jobs and industries around nutrient recovery and recycling from wastewater, including agronomic products manufacturing and exporting, as well as new business opportunities for European companies, specially SMEs, increasing their competitiveness in the global market.

Improvement of policy and market conditions

Improvement of policy and market conditions for large scale deployment of innovative solutions for the Circular Economy.


According to the EU’s own definition, “Horizon 2020 is the biggest EU Research and Innovation programme ever with nearly €80 billion of funding available over 7 years (2014 to 2020). It is the financial instrument implementing the Innovation Union, a Europe 2020 flagship initiative aimed at securing Europe's global competitiveness. It promises more breakthroughs, discoveries and world-firsts by taking great ideas from the lab to the market”.
Water2REturn Innovation Action was submitted under the call “Industry 2020 in the Circular Economy” (call identifier H2020-IND- CE-2016- 17), topic “Water in the context of the circular economy” (topic identifier CIRC-02- 2016-2017); Cross-cutting activities (Focus Areas), Work Programme 2016 – 2017. According to the

Work Programme, “this call supports systemic innovation, which is understood as innovation that aims at responding to a societal challenge by obtaining a systems-wide transformation through affecting the system's economic, social and environmental dimensions. This implies a transdisciplinary perspective that integrates technology, business models and economic organisation, finance, governance and regulation as well as skills and social innovation.
Systemic innovation therefore calls for the adoption of a challenge-driven, solutions-oriented research and innovation strategy that crosses disciplinary boundaries and involves co-creation of knowledge and co-delivery of outcomes with economic, industrial and research actors, public authorities and/or civil society”.

Specific objectives of the actions in this call include:

water2return-favicon A reduction of costs and emissions.

water2return-favicon A more efficient use of energy and resources.

water2return-favicon A cascade use of materials.