Creating 'white gold'

06 March 2012 - 02:43
By Vishanthi Arumugam

Conserving clean water sources and water resource management will make all the difference for the near future in Southern Africa. While many people in the region already have little or no access to clean drinking water, climate change experts said by 2025, 45% of the population in the region will be in a state of "water stress".

A tap. File photo.
Image: Esa Alexander A tap. File photo.
A tap. File photo.
Image: Esa Alexander A tap. File photo.

"[Water scarcity] is a global issue, but particularly dire for Southern Africa because of variable weather patterns and water courses shared between countries," said Makhosini Nyathi, director of corporate communications in the Department of Water Affairs.

The Lesotho Highlands project produces almost 50% of water in Gauteng, and the resource is referred to as "white gold" in that country due to the enormous potential value of clean sources.

The Limpopo River is shared by four countries. South Africa, Botswana, Zimbabwe and Mozambique all use the water basin, almost to beyond its capacity. The arrangement is favoured by the upstream countries - South Africa and Mozambique - who draw on a large portion of the water, leaving Zimbabwe and Botswana with a river that in some areas is made up of treated sewage water.

"Water pollution has serious consequences," Nyathi said.

"With a growing population, development and industry, clean water will definitely become more scarce."

Multilateral treaties are being negotiated to protect water flow in the region. And water conservation all the way down to household level is a priority for the sustainability of the resource.

A possible solution to the increasing scarcity of water is an innovation in water dehumidifying technology which allows a local Durban company to tap clean drinking water from thin air.

The company's Dew Catcher machine runs on energy from a wind turbine, and can produce 1000 litres of clean water per day, which is bottled in glass for sale to restaurants around Durban.

The locally built machine mimics a natural process of condensation. It draws in air and cools it to dew point, which allows a precipitation of pure, fresh water. The water is then run under a UV light and through filters which impart trace minerals.

There is no impact on existing water sources, which need to be conserved. Used more widely, the machines could also take the pressure off existing municipal infrastructure to provide water.

"The only by-product is clean, dry air," said Ross Badcock-Walters, owner and founder of Dew Catcher.

Numerous and regular independent tests have revealed the water to be free of biological impurities, proving it to be more than fit for human consumption.

"When the air condenses, impurities are separated from the water. The water cycle is mother nature's cleaning process," said Badcock-Walters.

The water-maker machine presents an ultimately renewable source, even in areas with low humidity, since vapour exists in the air in all climates.

Possible applications of the technology are far-reaching, from providing relief to water-polluted and water-borne disease areas and creating income for rural communities, to dehumidifying places where high humidity is a problem, such as greenhouses, libraries and art galleries. Temporary events like concerts or mass meetings could also benefit.

The water-maker is able to run on grid or generator electricity and is adaptable to rural specifications by running on wind or solar energy.Arumugam is a writer and researcher for Linkd Environmental Services