Desalination of seawater provides clean drinking water – and a couple of green dilemmas

Time is much better spent Kizingiti’s desalination plant supplies clean drinking water to approx. 4500 people in the city. A technique called “Reverse Osmosis” or RO is used, which is the most widespread technique for desalination. Large batteries stand next to humming machines that desalinate the water. Outside are several rows of solar panels and provide electricity for the facility. – Before the plant came, we had the water transported here all the way from the Amu, says Yusuf Omar Athumani, who is one of the town’s elders. The island of Amu is approximately 34 kilometers from Kizingit as the crow flies. – We waited for the water at the jetty and each family got around 40 litres. It was a challenge, he says. It was difficult to know exactly when the water would arrive, so Kizingiti’s residents often had to spend large parts of the day waiting. The desalination plant has particularly benefited the city’s women. It is mainly women and children who fetch the water. One of them is Fatma Yusuf Omar. She also lives in Kizingiti and is employed at the desalination plant. – Before the project, I had to get up at two in the morning to get water, she says, at the same time you can hear the faint humming from the plant in the background. – Now I have more time. Now there is a schedule, so I know when I can collect water and therefore plan around it. At the expense of the climate and the environment The desalination plant in Kizingiti thus provides vital water for an entire town, it is a climate-friendly plant that is powered by renewable energy and it has provided jobs for the town. But elsewhere in the world, desalination of seawater is far from problem-free. The majority of the world’s large plants are powered by fossil fuel, and this poses an environmental problem. Jiwoong Lee is a senior lecturer at the Department of Chemistry at the University of Copenhagen and he has, among other things, researched desalination methods. He holds a plastic lid from a take-away coffee cup to symbolize how the technology works. The lid should symbolize the membrane, through which the seawater is forced to be filtered. – To get one liter of desalinated water, it requires two liters of seawater into the system. This is due to the high de-icing rate of 99.7 per cent salt removal. That is why it is important to have effective filters and possibly carry out more filtrations, he says. – It requires a lot of energy, and mainly oil and gas are used. Most large desalination plants around the world thus emit large amounts of CO2. At the same time, the waste water from the facilities is a problem. It is called “brine” and it is water with a high salt concentration that also contains chemicals. By far most of it is discharged back into the sea and this can destroy the local marine environment. – It is never not a problem, says Jiwoong Lee. The amount of water that is desalinated in the large plants worldwide is expected to rise. That is why there are also researchers working to find new ways to reuse the waste water and more climate-friendly ways to desalinate water. Because despite the consequences the desalination plants have on the climate and the environment, people have used the drinking water they generate, as Jiwoong Lee emphasizes: – Water is essential. The World’s Best News was invited to Kenya by the Ministry of Foreign Affairs



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