Water scarcity in Europe is increasing due to climate change, especially in water-stressed areas in southern countries, most notably Greece, Spain, Italy, Cyprus and Portugal. Agriculture is the most important water use in the EU, accounting for about 40% of the EU annual use, but rising to 80% of water use in Mediterranean areas during summer. Wastewater reuse in the EU is still limited and mainly implemented in countries with severe water scarcity. The amount of reused wastewater (WW) in the EU is about 1,100 Mm3/year (<0.5% EU freshwater abstraction), with Spain, Italy and Portugal jointly accounting for over 60%. Most of the reuse is for irrigation purposes, and some countries already irrigate using mainly treated WW (e.g. Cyprus uses >75% treated WW for agriculture). Reusing treated effluent from waste water treatment plants (WWTPs) for agricultural irrigation has significant potential to reduce pressure on stressed freshwater sources. In water-stressed areas, the use of water resources for agricultural activities has negatively affected water bodies quality and made it necessary to obtain water from alternative sources (e.g. inter-basin transfers, energy-intensive desalination).
LIFE PHOENIX will demonstrate a flexible new tertiary multibarrier water treatment, which is adaptable to different WWTP typologies and water characteristics. This new treatment will be applied in highly water-stressed areas in central and southern Spain, and central Portugal. It will increase removal of organic matter, solids and pathogens using high-efficiency settling, filtration, flotation and biological technologies. These will be coupled with advanced oxidation processes (AOP)/disinfection steps able to go further in reducing the microbiological presence in water.
Specifically, the project aims to: Demonstrate and validate the new cost-effective multibarrier treatments in two WWTPs typologies, at large-medium scale in 3 WWTPs in Spain and Portugal and at small scale in 2 WWTPs in Spain, using different combinations of state-of-the-art and innovative technologies; Develop a Decision Support System (DSS) and a Sustainability Tool to ensure feasibility for each case; Minimise environmental and health effects, by reducingharmful disinfection/oxidation products and eco-toxicity (by >80%), compounds of emerging concern (CECs) and antibiotic resistant bacteria (ARBs) (>90%), microplastics (>97%), and carbon footprint (50%); Ensure water quality by online monitoring (e.g. toxins and pathogens) and offline analysis (e.g. eco-toxicity and ARBs); Reduce the cost of tertiary treatment; Recover >90% of nutrients (nitrogen and phosphorus); Test regenerated water and recovered fertilizer on experimental crop fields; Promote replication, transferability and market uptake of the new water treatment technologies; and Evaluate environmental, social and economic impacts.
LIFE PHOENIX will contribute to maintaining the operation of existing WWTPs, along with the setting up of new WWTPs, as per Regulation (EU) 2020/741 on minimum requirements for water reuse. The Regulation promotes water reuse by harmonising minimum water quality requirements for the safe reuse of treated urban wastewater in agricultural irrigation.
Expected results: Obtain reusable water, meeting EU wastewater reuse class A quality standards at 3 demonstration sites for testing large-medium WWTP technologies (El Bobar, Almonte and Fonte Quente WWTPs) and at 2 demonstration and 1 replication sites for small WWTP technologies (El Toyo, Talavera, Pulp WWTPs); Validation of indicator microorganisms and performance targets: (1) E. coli for pathogenic bacteria (5.0 log10 reduction), (2) coliphages for pathogenic viruses (6.0 log10 reduction), and (3) Clostridium perfringens spores for protozoa (5.0 log10 reduction); Minimised environmental and human health effects of water reuse: reduced eco-toxicity of regenerated water compared to drinking water (<5%), reduced CECs and pesticide levels, less microplastics (lower than 10 particles/m3), 50% reduction in carbon footprint for tertiary treatment due to lower energy consumption, total nitrogen (TN) in reusable water lower than 2 g/m3 and total phosphorus (TP) lower than 0.5 g/m3 (El Toyo and Talavera WWTPs) due to zeolite adsorption; Contribution to the protection of Doana National Park, by avoiding the use of 87.6 k m3 of freshwater per yearor the irrigation with lower quality waters (Almonte WWTP); 50% lower Operation and Maintenance costs (OPEX) (from 0.23-0.25 euro/m3 of current advanced tertiary), mainly due to lower pre-treatment chemicals consumption, O3 reuse, low membrane fouling, improved oxidation/disinfection steps, and solar-powered technologies; Reduced energy consumption (lower than 0.8 kWh/m3) due to the use of UV-LED technologies and solar power; Testing of the 900 kg/year of N-P loaded zeolite obtained, together with 125 m3/y reused wastewater, on 500 m2 of crop fields at El Toyo and Talavera WWTPs (250 m2 each); Operational PHOENIX DSS and Sustainability Tool; Replicability and transferability guides, and a business plan; 10 000 visits to projects website, participation in workshops and events of >300 people, and publication of 8 articles; Six direct and indirect jobs created as a result of the project; Establish a participative Stakeholder Advisory Panel (SAP), involving Public Authorities, Utilities, NGOs and CSOs, and experts and professionals, to ensure replicability and market uptake of the new technologies.