“With the obligation to purify better, new opportunities have been created to generate value of WWTP by-products”
The fruitful relationship that we have had for several years in the CETIM Technology Centre with Aqualia (FCC Group) collaborating as partners in various European projects has taken another step with the award of the LIFE ULISES, with both entities in the consortium. The objective of this research is the transformation of wastewater treatment plants into a new model of urban biorefinery, focusing on their energy self-sufficiency and the complete recovery of waste. We speak with the FCC Aqualia R&D Director, Frank Rogalla.
Why are sewage plants qualified as the new biofactories of the XXI Century? Why so much potential?
Wastewater contains vital elements, such as nutrients and organic matter, which can be extracted as products. The organic matter content can generate enough energy to overcome the need in purification. And nutrients are valuable, because nitrogen is generated in fertilizer factories with a lot of energy (between 10 and 15 kwh / kg N) and phosphorus is a mineral with limited reserves, concentrated in few countries. After the purification process, these nutrients can also be ingredients of selective biomass growth, which in turn can provide energy or raw material for other processes.
Why was this “wealth” not being exploited until now? What has been the trigger for wastewater, sludge and other by-products to become new raw materials?
Wastewater has not been previously valued because there were no incentives, legal or financial. With the obligation to purify better, driven by European directives, and the increase in raw material prices, new opportunities have been created to generate value of by-products. This trend is supported by European environmental policies, and the political pressures of carbon footprint reduction, which are transformed into new concepts of circular economy generated by climate change concerns.
The current wastewater treatment system demands a high energy consumption that can comprise up to 40% of the total operating costs of a WWTP. A paradoxical situation since wastewater has a great potential for bioenergy production. From Aqualia, in which lines of R&D are working to make WWTPs energetically self-sufficient?
In Aqualia we have identified that the largest bill we pay as an operator is electricity, and at the same time we know that the energy contained in the wastewater should cover the needs of the treatment itself – an optimized WWTP should be self-sufficient.
Then, with the support of Technology Centre, universities and suppliers, on the one hand we have worked on the optimization of existing plants, minimizing energy consumption with control systems, and adding novel concepts of processes such as Anammox. On the other hand we have reconsidered the processes, adapting anaerobic treatments such as UASB and AnMBR to take advantage of the most favorable temperature and concentration in some effluents in our geographies. And we have also adapted radically different solutions such as the cultivation of algae to replace conventional processes, which avoid any consumption of electricity, and avoid producing undesirable waste such as sludge, and on the contrary generate energy and bioproducts such as fertilizers or plastics.
In your opinion, what is the role of technology and innovation in this transformation of Wastewater Treatment Stations in Biofactories?
Debugging is based on very old technologies and processes, such as activated sludge, invented before the First World War. In recent decades, knowledge of biotechnology and process control has accelerated, and at the same time there are new pressures on environmental policies and energy costs. This set of favorable factors and external requirements generates a great need and opportunity to apply innovative solutions, and enhances the application of new technologies and innovation, since the return is fast and the risk limited – continuing with the conventional one has a higher risk and a higher cost than to change course.
During the next 3 years they will lead the LIFE ULISES project that the European Commission has just granted them and in which they integrate a team with CETIM. What is this project about?
LIFE Ulises responds to the need to equip small urban centres with sustainable purification, since the energy consumption of conventional solutions increases exponentially inversely proportional to size – and waste management in a decentralized manner is more complex. LIFE Ulises will evaluate and optimize all the alternatives of technologies adapted to smaller installations, with the idea that water, resources and energy can be reused in an easier way being close to the user.
Our collaboration with CETIM began in 2016, and since then, we have prepared several European proposals, in H2020 and LIFE Programs. Currently, we work together in LIFE Ulises, where CETIM, specialized in water treatment technologies and circular economy, will carry out the recovery of nutrients through enzymatic hydrolysis and membrane technologies.
In addition, as a result of the collaboration and joint effort of these years, a new H2020 project, REWAISE – Resilient WAter Innovation for Smart Economy, has been selected for funding.
Will LIFE ULISES allow transforming WWTPs into sustainable and self-sufficient facilities that generate resources, being themselves their only source of food?
The idea is that small WWTPs that are the focus of LIFE ULISES are self-sufficient and remotely controllable, perhaps as small automatic washing machines. Many greener solutions that rely on natural processes and “biomimicry” are also integrated into the project, avoiding the consumption of external energy and the production of undesirable waste.
How will the quality of the new resources be controlled and that they are safe for use in agriculture and, therefore, for human consumption?
Quality control is very important when water and resources are reused, and we work with sensor suppliers and control systems to take advantage of new monitoring technologies, and with fertilizer companies to adapt to the specifications of distributors and users.
What would be the steps to transfer the project to the market and scale the results to other treatment plants for general application and use by the population? It would be a big jump environmentally speaking.
The LIFE Ulises project is in line with other initiatives, such as the European H2020 Run4Life project that focuses on decentralized resource recovery. The main objective is to abolish the traditional concept of sewage treatment plants, and some of our partners already build new urban blocks such as in Ghent (BE) or Helsingborg (SE) where resources are used in buildings – also in Japan in many buildings the Waste water for toilets, as we are evaluating in the Vigo Free Zone. The main unknown is the critical size so that the new ways of managing the resources and waters recovered are economically and socially viable.
For Aqualia, the use of WWTP resources is essential in the integral management of the water cycle. Why?
Aqualia’s main objective is to be a responsible company, committed to the UN SDGs, contributing our services to sustainable cities, responsible production and water and a healthy life. New ways of managing water and resources, avoiding contaminating clean water with sewage, will save a lot of expenses on transportation and pumping, and will help transform organic matter concentrated into energy.
What other innovative solutions have been launched in Aqualia to respond to the scarcity of resources?
In addition to the repositioning of wastewater as a resource, using natural technologies and advanced control in decentralized solutions, we are working throughout the entire water cycle to reduce the consumption of resources and energy, measuring and reducing the carbon footprint with systematic audits. Also in desalination we are changing the paradigm, reducing energy consumption by a factor of 10 with the H2020 Mides project (Microbial desalination), and starting another European project to recover brine minerals.
Aqualia is a management company for the integral water cycle, controlling all phases from the supply of drinking water to the sanitation of waste. It is owned by the FCC service group (51%) and the Australian ethical fund IFM Investors (49%). According to the latest Global Water Intelligence ranking (August 2019), it is considered the fourth largest water company in Europe by population served and is among the top ten in the world, according to the latest Global Water Intelligence ranking (August 2019). It currently serves more than 25 million users in 1,100 municipalities in 18 countries.