New water filtration system holds promise for rural poor

Inhabitants of the Mdori village, Tanzania taste the freshly filtered water produced by the Reverse Osmosis Solar Installation system developed by the German-based Karlsruhe Institute of Technology. Image credit: Andrea Schäfer
Date:24 June 2014 Author: Sean Woods Tags:, ,

A lack of clean drinking water is a real killer, especially here in Africa. Happily, this could soon change, thanks to the development of a robust, mobile solar-powered water filtration system by the German-based Karlsruhe Institute of Technology.

Like many areas in Africa outside the rainy season, the Mdori area in northern Tanzania – where the system, developed by hydraulic engineer Prof Andrea Schäfer and photovoltaic expert Prof Bryce Richards, was tested – is hot and dry. And, apart from being water scarce, the little ground water available has a high salt concentration and fluoride levels 40 times the limit deemed safe for human consumption. Basically, it’s undrinkable.

Tests on their ROSI (Reverse Osmosis Solar Installation) water filtration system began early this year to determine if it would, in fact, be capable of removing undesired substances, bacteria and viruses from the brackish water – and so far their data’s looking good.

The system can be operated with solar and/or wind power. It combines ultrafiltration membranes with pore sizes as small as 50 nm (to retain macromolecular substances, particles, bacteria and viruses) with membranes below 1 nm for nanofiltration and reverse osmosis water purification.

As the system is powered directly by the sun and doesn’t incorporate batteries, the amount of potable water it can produce depends largely on the weather – but, let’s face it, sunshine is an abundant commodity in our part of the world.

Both academics conceived ROSI in Australia, then developed it further in Scotland before starting their field tests at the Nelson Mandela African Institute of Science and Technology in Tanzania. The next phased of their project involves installing systems at a number of predetermined locations.

One system can supply about 50 people with high-quality drinking water as well as water for household use. Schäfer and Richards are now looking for companies to manufacture, install, support and operate plants in the rural regions of Tanzania.

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