Villagers collecting clean water from the Burani WaterKiosk. (Image: Boreal Light)
Villagers collecting clean water from the Burani WaterKiosk. (Image: Boreal Light)

Water scarcity in Kenya is common and much of its population has no access to clean water. Treating wastewater using renewable energy is key to solving the problem and one German company is providing simple, affordable solar-powered water treatment to a Kenyan village.

According to a study by the Potsdam Institute for Climate Impact Research (PIK), ten out of every hundred people run the risk of experiencing absolute water scarcity in the event of global warming of 3° Celsius. Particularly in dry areas, it is vitally important to make optimal use of water as well as treat wastewater using renewable energies.  In its policy paper dated August 2019, the German Federal Ministry of Economic Cooperation and Development (BMZ) clarified that these regions will be better equipped for the effects of climate change when water is protected and used sustainably.  

The WaterKiosk
One example of this kind of sustainable use is the WaterKiosk, a solar-powered water treatment system from German company, Boreal Light GmbH, in partnership with specialty chemicals company Lanxess, which supplied its reverse osmosis membrane elements to the project, and atmosfair GmbH, a German non-profit organisation. Eight Lewabrane membrane elements with a total membrane surface area of more than 50 m3 are being used to[MC1]  supply the population with clean water in the village of Burani, Kwale county, Kenya, 30 kilometres south west of Mombasa.

The Burani WaterKiosk is one of Boreal Light’s solar-powered water treatment projects to enable access to clean drinking water. The Berlin-based company specialises in simple, inexpensive, battery-free water treatment solutions powered by solar energy. The kiosk was built in partnership with atmosfair, also based in the German capital. Through the promotion, development, and financing of renewable energies in more than 15 countries around the world, atmosfair actively contributes to reducing CO₂ emissions.

The technology
Raw water with a high salt content of 4,800 ppm, which comes from a 120 m deep borehole, is treated to become drinking water using solar-powered reverse osmosis. Raw water is pushed through the semipermeable membrane walls, and substances and impurities that are dissolved in the water are almost entirely removed.

Dr. Jens Lipnizki, head of Technical Marketing Membranes in the Lanxess Liquid Purification Technologies’ business unit, explained: “Under standard conditions, salt retention of our reverse osmosis elements for brackish water is approximately 99.7%. The retention of organic compounds is often even better, so that critical substances can also be removed from the water.”

Solar-powered
The Winture Planet Cube ABW desalination system from Boreal Light does not have a battery and requires neither a diesel generator nor the grid. It is powered directly by a 10 kW solar panel and supplies up to 20,000 litres of drinking water every day to the village and its neighbouring community.

The permeate is used in three different applications as drinking water, irrigation water for a vertical farm, and for three 12,000 litre fisheries. The brine is used for the sanitation water supply of the village. In addition to producing fresh water from highly saline sources, the system functions as a low-voltage charging station for up to ten mobile devices at the same time.

Lewabrane membrane elements are produced in the latest fully automated production facility in Bitterfeld, Germany. The chemistry approach for the membrane places the emphasis on higher cross-linking of the polyamide layer and, therefore, higher resistance to cleaning chemicals, more stable rejection of mixed ion salt solutions and lower surface charge on the membrane to reduce the fouling tendency.

Hamed Beheshti, CEO of Boreal Light GmbH and member of its Board of Management, said: “Only about half of Kenyans have access to clean drinking water. Those who cannot afford a tap water supply often have to walk more than 10 kilometres to collect non-potable water from a borehole. The Burani WaterKiosk is a real relief for residents.”