The current water emergency has multiplied the need for regenerated water in the Barcelona metropolitan area. One in every four liters today comes from reuse, a process in which wastewater treatment plants, whose function is to mitigate the human impact derived from activity in cities, play a determining role.
Aigües de Barcelona aims to comprehensively transform these traditional treatment plants to convert them into ecofactories, that is, factories that are energy self-sufficient and that also convert waste from water purification into useful products for agriculture, construction or mobility. . The transformation of a treatment plant into an ecofactory is an exponential leap in the reuse of resources, especially in terms of the reuse of waste. In 2023, the company will value 100% of the sludge generated in the treatment plants, a material rich in organic matter.
65% was used to make compost, 31% was used directly as fertilizer and the remaining 3% to make biogas and thermal drying. The company makes energetic use of the biogas produced in the ecofactories. In addition, Aigües de Barcelona has the Life Nimbus project underway, co-financed by the LIFE program of the European Union, and in collaboration with Cetaqua, the Autonomous University of Barcelona and TMB, to feed with biomethane extracted from biogas from the ecofactory of the Baix Llobregat a public bus in the metropolitan area of ??Barcelona. Plain and simple, it is about the strict application of the circular economy. An ecofactory is a self-sufficient center that obtains the electricity it needs from renewable sources, which generates a positive environmental impact and provides shared value to society.
Aigües de Barcelona sees a clear path to strengthening the resilience of a metropolitan area where more and more studies warn that, in the near future, episodes of extreme drought like the current one will be frequent. It is necessary to extend water regeneration up to 100%, in a system that regenerates in a continuous cycle. One liter of water obtained in this way reduces the CO2 footprint by half and requires only a third of the energy of a liter of water from desalination. The water from ecofactories is generated in the same place where it is necessary for consumption and, therefore, does not have to be transported.
The use of regenerated water also allows us to release resources from natural water sources (rivers and aquifers), improving their quantity and quality. The virtuous circle of ecofactories does not end here: the one in Baix Llobregat is already pumping regenerated water upstream to Molins de Rei. This same water is collected at the Sant Joan Despí water treatment plant, downstream, to convert it into drinking water. A continuous cycle of water regeneration, a resource that is already scarce throughout the planet and that in the metropolitan area of ??Barcelona will be increasingly limited.
During last year, of the almost 240 cubic hectometers of water that were purified in the metropolitan region, 57.9 cubic hectometers were regenerated, the equivalent of the annual water consumption of one and a half million people. The vast majority of this water, four out of every five liters, was destined for environmental uses such as, for example, pre-drinking water or maintaining the ecological flow of rivers. The remaining part of the regenerated water was used for agricultural irrigation and urban uses. Even so, these figures are still far from the 130 cubic hectometers per year of regenerated water that would be necessary, according to the projections of various institutions, in the metropolitan area of ??Barcelona to address the structural water deficit. Administrations and companies, let’s get to work.
