DRINK UP – SAFELY

With parts of the country facing a water crisis, alternative and cheaper methods for water purification have become vital. Using macadamia nuts as a key component, Murendeni Mafumo has created a water filtration system with a difference.

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Feed channel spacer Membrane HERE’S SOMETHING THAT not everyone knows: South Africa is the world’s biggest producer of macadamia nuts. How sweet it is to beat the Australians at something… especially when that something happens to be one of their own native plants.

We certainly could have used Murendeni Mafumo (right) on our team at last month’s inter-office quiz. Macadamias are an important part of the life of Mafumo, 31, a chemistry graduate and former Cape Town and Johannesburg water employee. Monitoring water treatment systems, research and development were his key focus areas, but he always wanted to do more to create access to water for people living in our country’s rural parts.

In 2015, he decided to take matters into his own hands and started Kusini Water. Using a low-cost membrane that makes rainwater or ground water drinkable, Kusini water provides clean water for residents in Mafumo’s hometown of Thohoyandou, Limpopo. His system is entirely designed and built in South Africa, and a key ingredient of the system is crushed macadamia nuts. The nuts are used for the activated carbon filter, which removes toxins, before the water is pushed on to the nanotech membrane.

“The industry currently uses reverse osmosis to purify water,” says Mafumo. “Compared to our system, this process uses 60 times more water for the same amount of energy.

“We use solar power, to save electricity, and locally sourced macadamia shells and moringa seeds as a filtration medium. Our membrane removes 99 per cent of bacteria.”

As a municipal worker, Mafumo saw the challenges that cities face in making water available for everybody. “There is little room for innovation in the municipality structure. It’s too limited and centralised. This is fine for large suburbs, but for the poorest parts of the country no rain means no water. With global warming rapidly reducing rainfall, the situation only stands to get worse,” Mafumo explains.

“Systems need to be easy to deploy in rural communities; they need to be easy to operate and energy-efficient. Be using locally sourced material, which we monitor via the Internet of Things, we hope to achieve this.”

Mafumo’s filtration membrane system is far simpler than you’d expect. The first stage of purification involves using moringa seeds to clarify the water. These seeds absorb organic matter in ground water. Next, to combat the high turbidity of water in Limpopo, the shells of the macadamias are used to extract chemicals and toxins from the water. The shells are burnt, cooled and the water is filtered through them. The water then goes through the membrane which eliminates viruses and bacteria, making the water safe to drink.

Kusini Water serves rural communities, works with municipalities, assists large factories to manage in-house water re-use and helps businesses trying to go green.