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  • Researchers create novel water purifying filter

Image credit: ETH Zurich

Speed read

  • More than 780 million people lack access to clean water, says the WHO

  • A novel filter that weighs less than 100 grams could help provide clean water

  • But an expert says it needs further testing to ensure safety of water

[CAPE TOWN] A team of researchers have developed a membrane-based water filter that can provide up to 300 litres of clean drinking water.
 
The WHO says about 780 million people worldwide, especially those in Sub-Saharan Africa, lack access to improved water source.
 
The researchers from the Swiss Federal Institute of Technology in Zurich (ETHZ) in Switzerland announced last month (22 July) that DrinkPure filter, which they have developed, is based on a simple screw-top design that fits onto any plastic bottle.
 
Wendelin Stark, a professor of functional materials engineering at ETHZ, who helped create the innovation, says: “It requires no manual, no electricity, and no additional tools or training needs. You simply screw it on, and you drink [the water].”

“One DrinkPure water filter provides enough drinking water for one person for one year, after which the membrane and activated carbon can be replaced over and over again.”

Jeremy Nussbaumer, Swiss Federal Institute of Technology, Zurich (ETHZ)

 
The researchers say they used a novel porous polymer membrane developed though  nanotechnology, thus making  DrinkPure allow the filtration of particles as small as 90 nanometres, including bacteria and protozoa, at rate of up to one litre a  minute.
 
They add that the innovation which weighs less than 100 grams, with a target cost of less than US$20 a filter, has two pre-filtration components — a capture filter that separates large particles and an activated charcoal layer that removes odour and chemical contaminants.
 
 
“One DrinkPure water filter provides enough drinking water for one person for one year, after which the membrane and activated carbon can be replaced over and over again,” explains Jeremy Nussbaumer, leader of the project and a research assistant, in a release.
 
In order to fund the tools to manufacture the filters, the researchers launched a crowdfunding campaign last month (17 July) with a goal of raising US$40,000 by this week (26 August), but have as of today raised more than US$71,000.
 
Nussbaumer says they plan to have the first filters completed and sent to project supporters for distribution by January 2015 in Sub-Saharan Africa.
 
 Nussbaumer adds that Water & pH soluces, a Swiss NGO that works to provide sustainable, affordable access to safe water and sanitation to communities in Sub-Saharan Africa, plans to distribute DrinkPure for testing in five villages in Mali.   
 
Stark tells SciDev.Net: “The aim is to develop partnerships with partners and local companies who can develop the membranes themselves”.
 
The researchers say DrinkPure water filter could be used as part of relief efforts following natural disasters, such as tsunamis. “We would like to see these membranes and filters used …in places experiencing environmental issues,” says Christop Kellenberger, a member of the DrinkPure research team.
 
 
Nonhlanhla Kalebaila, a research manager of drinking water treatment and quality at the South Africa-based Water Research Commission, says the use of small-scale water purification systems in Africa is increasing rapidly. “Water quality and supply in Africa as a whole is a very touchy subject and has been the topic of strikes and protests in South Africa in the last few years,” she says.
 
But Kalebaila adds that independent research is needed to ensure the accuracy of water filtration devices and the safety of water that flows from such tools.
 
Link to video of DrinkPure

This article has been produced by SciDev.Net's Sub-Saharan Africa desk.

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