Anagrafe della ricerca

Conventional wastewater treatment technologies are characterised by high energetic and economic costs (72 billion €; 25% of 2014 EU environmental expenditures) that represent a big challenge for sustainability. Moreover, approximately 70% of domestic wastewater sent to treatment is actually made up of diluted greywater, which is discharged from showers, bathtubs, washing machines, and hand washing sinks and whose contaminant content is much lower than in blackwater from toilets. Since conventional wastewater treatment technologies are less efficient when dealing with diluted wastewater, separating greywater would enhance operative conditions for the local treatment plant. Furthermore, onsite greywater purification would also provide a local source of reusable water, which could be recycled for other uses (e.g., toilet washing and irrigation, depending on local regulation) that would otherwise employ clean water. This reuse would turn greywater from a waste product into a resource, but it is currently hampered by the lack of an affordable treatment technology for that is able to operate in densely inhabited urban areas where space is limited and expensive. The aim of SUPERGREEN is to couple greywater recycling as a nutrient-rich irrigation source together with the use of green walls, which are vegetated vertical elements that exploit unused building surfaces to provide benefits such as greening, improved aesthetics, and shading. SUPERGREEN will feature an extensive campaign of laboratory experiments to investigate the efficiency of green walls in treating greywater. The analysis will consider different mixtures of conventional and innovative materials as growing media, and it will identify the most efficient green wall configurations in terms of treatment efficiency. The proposed approach will represent a sustainable greywater treatment technical solution characterized by low energy requirements and much less space demanding than other natural treatment options.