A UK-wide research project aiming to make fresh water by removing the salt from sea water was launched at the University of Glasgow in October 1. Project leader Anna Amtmann and her team plan to use sunlight-powered microorganisms to extract the salt from seawater.
‘World-agriculture uses 70% of the fresh water resources,’ Amtmann says. ‘Irrigation of fields with seawater – even if diluted – leads to the build up of salt levels in the soil that are toxic to common crops.’
Salt is toxic because it causes dehydration of cells in most living organisms, explains Amtmann. For example, when we sprinkle salt on spilled wine we take advantage of its ability to suck up water. Salt can also damage cells by distorting the shape of their proteins, preventing them from functioning normally.
‘Marine organisms have evolved strategies to adapt and avoid toxicity,’ says Amtmann. The team will grow these organisms in sea water and fit them with a set of molecular engines to take up salt until they are packed with it. The salt-packed cells will die, leaving fresh water, and a salty waste product that could be used to produce biofuel, biopharmaceuticals or biocosmetics.
‘There is a global water crisis out there,’ says Bill Sloan, Professor of Environmental Engineering at the University of Glasgow, ‘for example in the Horn of Africa, where the worst drought in decades is causing malnutrition and starvation’ 2. There are also problems closer to home, Sloan points out, with the south-east of England suffering periodic water shortages.
While the potential benefits of the project are clear, there are risks such as environmental contamination by the de-salting organisms. That is why the team also includes researchers in environmental policy and risk assessment. ‘Understanding social acceptance is absolutely crucial’, says Amtmann. ‘Scientists should know from the beginning what might actually be acceptable to potential clients.’
