Though the Earth is covered with water, 95% of it is undrinkable, and water scarcity threatens millions of people. But researchers in Egypt have found an inexpensive way to turn salt water into drinkable water, and its implications could be enormous.
ALEXANDRIA — Leaving Atlanta in 1997, using her last dollars before the long trip home, Mona Naim picked up a book called Standard Handbook of Hazardous Waste Treatment and Disposal — light reading for the flight back to Egypt. The purchase sparked nearly two decades of experiments at Alexandria University that may eventually affect billions of lives.
The research Naim began in 1997 culminated in an article published in August in the academic journal Water Science and Technology. In the article, a team of Egyptian researchers — Mona Naim, Abeer Moneer, Ahmed El-Shafei and Mahmoud Elewa — described a simple and efficient new process for turning salt water into clean drinking water.
In the weeks after its publication, news of the research drew headlines around the world. The team behind it has attracted less attention, but as a group of Egyptian scientists using a government grant to achieve outstanding results, their story serves as a model for what local researchers can accomplish when they work together and are supported properly.
Water, water everywhere
Water covers 70% of the Earth's surface, but 95% of it is undrinkable. MIT estimates that 700 million people, 10% of the world, don't have access to clean drinking water. By 2025, that number may be 1.8 billion. Earth's population is rapidly increasing as freshwater resources simultaneously decline. Experts have said "the era of easy water is over."
Water scarcity is especially relevant to Egypt, where water availability per capita has fallen by more than 60% since 1970. By United Nations standards, Egypt is more than 30% below the threshold for scarcity and is considered "water poor," a condition that is expected to worsen in the years ahead.
The solution is to find a way to make undrinkable water drinkable — turning salt water into fresh. Unfortunately, the current methods are expensive and inefficient. The most widely used is reverse osmosis, which requires a substantial amount of electricity to push tainted water through a membrane that removes unwanted particles. A report by Yale University estimates that, at best, it costs twice as much to desalinate water with reverse osmosis as it does to process average groundwater.
Naim and her team developed a desalination technique that uses up to 70% less energy than reverse osmosis and can be powered by solar energy. Their work brings a key innovation to the field of desalination: a more efficient and inexpensive membrane. For the first time, this membrane may make it feasible to desalinate large amounts of water using pervaporation, a technique in which water is purified using a combination of evaporation and membranes.
Their method uses cheap and abundant materials and can process water with very high levels of salt and contaminants. The team's findings are among the most promising in this field in years and may eventually relieve some of the pressure on the Earth's clean water supply.
A team and a process
Now 72, Naim is professor emeritus in the Alexandria University Faculty of Engineering. She proudly calls herself the mother of the group, "her family" — a description they all embrace.
It's not hard to imagine how this team dynamic could achieve results. Sitting around a coffee table, they joke and compliment each other, laughing about stories from their time together.
Naim has lived in Alexandria all of her life. Her father, a professor of medicine at Alexandria University, inspired her love of science and encouraged her path towards engineering. In registering for her master's degree in 1967, her advisor "made me work on membrane fabrication," she says. The topic has become her area of expertise over a long career of teaching and research.
Her work on desalination is not her only research of note, but she recognizes that it is probably her most noticed. The attention the project has received took her by surprise. "It was the first time that anyone showed us appreciation. We got so many emails," she says.
Sitting next to Naim is Abeer Moneer, associate professor at the National Institute of Oceanography and Fisheries and another Alexandria native. "It was my always dream to get to the Faculty of Engineering," Moneer says. Her father, an employee with the Ministry of Social Affairs, and her mother, a teacher, encouraged her studies.
Moneer has been working closely with Naim since the beginning of her master's degree in 1991, when she began research on liquid membranes. Moneer waited to start work on her PhD until 1998, when Naim returned to Egypt. Researching together for more than 25 years, the two can — and often do — finish each other's sentences. Their expertise and personal relationship made the project possible.
Mahmoud Elewa, head of the Research Development Department of the Arab Academy of Science, Technology and Maritime Transport, earned his PhD on the same day as Moneer in 2005. Like Moneer, he has worked closely with Naim since his time in university. "I assigned pervaporation for desalination as his topic," Moneer says.
"At the time, nobody in the whole world was working on this topic," Elewa says. "I could find no documents on desalination by pervaporation."
Ultimately, Elewa joined the private sector, where his career has concentrated on research and development. "I like academics and research, but I don't like teaching," he explains. "My background is practical."
The final member of the group is Ahmed El-Shafei, associate professor of agricultural and biosystems in the Faculty of Agriculture. Shafei is a comparative newcomer to the group, having started working with Naim and Moneer in 2010.
Shafei's father, who worked in a copper factory, had dreams of his son becoming a doctor. "He didn't force me, but he encouraged me to study biology," he says. "He had only a preliminary degree, but he loved mathematics and taught me to love mathematics."
Since receiving degrees in agricultural and civil engineering, his career has focused on irrigation, drainage, soil mechanics and pollution — areas where science, agriculture and engineering meet. During an irrigation project in 2010, Shafei sought advice on desalination from colleagues in the Faculty of Engineering, an encounter that completed the team.
"From this day, I haven't left them alone," he says. Shafei's expertise contributed greatly to the project, his colleagues say.
Historically, university research in Egypt has been underfunded. In 2011, the World Bank estimated that funding for research and development amounted to just 0.43% of GDP. By contrast, the United States spent 2.73%, South Korea 4.04% and Russia 1.01%.
But the team made good use of the resources available. In 2010, they responded to a call for research proposals on "new methods for desalination" from the Egyptian Science and Technology Development Fund (STDF), a government initiative to strengthen research in science and technology. Of 450 applications, seven were chosen. The team won two of those seven grants, receiving $230,000 to conduct their research on both liquid membranes and pervaporation as methods of desalination.
Pervaporation is generally used for separating liquids and had not previously been very successful as a method for desalination. "There had been trials, but they had not seen very good results," Naim says, explaining that previous tests were both complicated and uneconomical.
The process they developed is simple, as they explain it: Salt water is placed in a holding tank, ideally heated to a point around 40 degrees Celsius. The water is then circulated over a membrane stack, consisting of a plant-derived cellulose mixture, which separates water from unwanted particles — in this case, salt and other chemicals. Underneath the membrane, an air current flows in the opposite direction, vaporizing the water flowing through the membrane. The water vapor, fully purified, is then condensed and collected.
"We tried many different blends to reach the optimum membrane," Naim says. "It took years." After experimenting with more than 100 combinations, the team developed a membrane than can draw clean water from a more than 40% salt solution. By comparison, the Dead Sea is only 34% salt. More importantly, the process is cheap, using about a third of the energy reverse osmosis requires and inexpensive materials available in countries facing water scarcity.
The team has already received interest from a number of organizations hoping to assist in the next steps of moving the project from prototype to pilot plant and eventually large-scale, commercially viable plants that could help billions facing water scarcity.
Naim says she hopes their success can serve as an example of what local scientists can achieve if they have access to research funding. "I am proud that the STDF was founded and it started assisting scientists and researchers because really it helped us a lot," she says.
The researchers also hope the project might inspire other Egyptian scientists to embrace teamwork. Interdisciplinary research in Egypt is rare, the team members say. "Here in Egypt, everyone likes to work on his own. Research is only individual," Moneer explains.
"We are like a puzzle," Moneer adds with a smile, describing how well the team fits together.
Ultimately, they hope their findings will benefit mankind and prompt more research into desalination. "We need the world to put great effort into desalination, because it is the only way we can produce water for drinking and irrigation — for life," Naim says. "Water means life."