Scientists in the UAE have taken a crucial step forward in efforts to develop more effective desalination and water treatment in the Gulf.
A team from the NYU Abu Dhabi Water Research Centre said it has manufactured the first reverse osmosis membrane system in the country. It is not new technology but the membranes, which work by forcing saltwater through tiny pores, have previously been imported.
The development opens a path to local industrial-scale production that can be tailored to suit the conditions in the Gulf, boosting sustainability and bolstering water security.
“It is a huge achievement,” Nidal Hilal, director of the centre and a professor of engineering at the university, told The National. “It is a life achievement in a way. We were able to show that we can develop this here."
Countries across the Middle East have long sought ways to ensure they have reliable sources of water. Desalination – removing salt from seawater to make it drinkable – helps to do that.
Boosting water security
Today, about 50 per cent of all desalinated water in the world is produced in the Middle East and North Africa and this is expected to grow. While techniques such as atmospheric water generation are being assessed, most of the UAE’s potable water – about 40 per cent – comes from desalination, the latest figures show. But it could be higher, with desalination considered crucial to helping supply the UAE's future water needs as the population increases.
Yet the dominant technology used in the Middle East since the 1950s is energy-intensive thermal desalination, which is essentially boiling seawater to remove the salt. Reverse osmosis, by contrast, pushes salty water at high pressure through tiny pores in membranes. The technique uses about a fifth of the energy needed for thermal desalination.
While it is the preferred choice for new installations around the world, the transition in this region has been slow, partly due to the harsh conditions of the Gulf, legacy reasons and the abundance of fuel. Less than 20 per cent of desalinated water in Abu Dhabi comes from reverse osmosis, but its use is increasing.
"It is much [more] environmentally friendly compared with other technologies,” said Prof Hilal, adding that reverse osmosis does not use chemicals to separate the salt. "You could save a lot of ... energy."
A crucial part of the research aims to make membranes suited to conditions in the region. The Gulf has high salinity – more than 50 per cent higher than the Atlantic – meaning more pressure is required to remove the salt. The turbidity, which refers to the clarity of the water, is also higher, meaning it is cloudier with more particles. This can cause membranes can become clogged.
“That is the biggest challenge,” said Prof Hilal. “You need a tailored, specific membrane.”
Scientists could tweak the surface of the membrane to repel certain impurities found in the water. Those unique to the Gulf come from algal blooms and silica from the region's geology, Prof Hilal explained. Desalination could be made even more efficient by treating the water before it is passed through the membrane.
“Researchers in general produce membranes in the labs ... on a small scale for study,” he said. “We produce a paper, we publish the results, we get excited and that's it.”
But Prof Nidal set about proving the membranes could be made in the region by creating a mini desalination system at the centre's lab. Membranes are made from plastic – even discarded plastic bags or bottles – and then reinforced with fibreglass to make what looks like a long tube. Saltwater enters through one side and is pushed through membranes, coming out as filtered water.
A standard reverse osmosis membrane module can generate between 75 litres and 380 litres of desalinated water an hour, depending on the size and design of the system. Such a device currently costs about $500, but that is expected to drop.
A further issue is the disposal of brine, a byproduct of desalination, which can harm marine life if not managed properly. Brine also contains precious chemicals such as lithium and Prof Hilal said the centre was looking at brine mining projects to extract and reuse them.
The UN has said the Middle East and North Africa includes 15 of the world's 20 most water-scarce countries. It forecast the situation will worsen as populations increase, with other factors such as conflict, unsustainable water management and economic growth also having an effect.
Addressing growing need
It is a global issue and, in 2022, the UN said about half of the world’s population experienced severe water scarcity for at least part of the year. Prof Hilal said sustainability was important to him and the centre's work was dedicated to finding solutions to these global issues.
"The amount of water we have globally is the same amount of water we had millions of years ago,” said Prof Hilal, who this month was named among the top one per cent of researchers around the world, according to Clarivate Analytics. “The population is expanding. Our habits are different. We're using more water than our ancestors – a lot more. Future generations are not going to appreciate that."
He thanked the UAE's Tamkeen company for its support. The next step is to team up with businesses to develop the system and make it ready for potential commercial use, turning the several models currently at the lab into thousands of systems.
“Taking this to a larger scale is a new thing for academics,” said Prof Hilal. “We're looking for people or industries or funders. They come to us and we have a partnership with them and develop this here.”
