Mobile desalination plants, a timely alternative
Faced with the emergency situation due to the lack of water, engineers and economists consider that mobile desalination plants can be an “emergency” solution, but not a “structural” one. This was stated in the second session of the cycle of debates and conferences on water management organized by the Intercollegiate Water Observatory, formed by three colleges of engineers (Industrials, Agronomists and those of Roads, Canals and Ports) and that of Economists. The conference was held this afternoon in Girona and dealt with the water transition, that is to say, the transition from rainwater to water that comes from technology.
In this sense, desalination is one of the options that allow water to be produced constantly, regardless of the weather. This was explained by the chemical engineer Guillem Gilabert, an expert in the field, who gave as an example areas of the Spanish state where this system is already used, such as Ibiza or the Canary Islands. “On Hierro Island, 100% of the water consumed is desalinated”, said Gilabert.
However, Gilabert has remarked that the desalination model is designed for large plants, such as the Prat and Tordera plants, which have specific legislation and can offer drinking water at a lower cost. “If we look at a family of four, the energy consumption to provide them with desalinated water for a year would be the same as what the refrigerator at home supposes,” Gilabert specified.
The case of Lloret de Mar
One of the initiatives that has recently emerged in relation to desalination is that of the hotel sector in Lloret de Mar (Selva), which wants to invest 1.5 million euros in a mobile desalination plant to be able to fill the swimming pools of its establishments. This project could be replicated in other municipalities on the Costa Brava, where the drought also affects tourism.
Gilabert has positively assessed this proposal, as it “demonstrates the importance of water as an engine to boost any economic activity”. However, he added that regulations would need to be drawn up to regulate the implementation of these desalination plants and that “they could be deployed with all the guarantees”.
Mobile desalinators, not the definitive solution
Engineers and economists have also agreed that, despite the fact that mobile desalination plants can ensure water supply in emergency situations like the current one, they should not be considered as a “structural solution” for drought . The president of the Circular Economy and Climate Change Commission of the Industrial Engineers of Catalonia, Marc Oliva, has argued that the definitive solution is to build large desalination plants that allow water to be supplied at a reasonable cost.
Oliva said that “it is good that initiatives appear to contribute small grains of sand, but the image of coastal municipalities dotted with desalination plants is not the great long-term solution” but that these mobile plants “must be placed in the context of emergency that we are living right now”.
The role of aquifers
At the same time, when moving towards the water transition, engineers and economists have also called for more attention to the role that aquifers should play. “We have to work in two directions”, explained Oliva. On the one hand, using them as a reservoir; but on the other hand, also feeding them with regenerated water.
In this sense, the experts have proposed that the regenerated water that comes out of the treatment plants on the coast is not poured into the sea, but injected into the aquifers (as is already done in the case of the Llobregat river). “A great effort is being made to purify it and it ends up being diluted in the sea, from where it is also being collected to desalinate it”, reflected the president of the commission.
During this second day of the Intercollegiate Water Observatory, among the presentations, there was also talk about the use made by the agri-food industry or those technologies and systems that must allow the production of more food with less resources . The third of the days will be held in April at the headquarters of the College of Agricultural Engineers in Lleida.