International innovation title for UCT engineers’ greywater solution

03 May 2023 | Story Supplied. Read time 8 min.
The victorious NextGen Engineers team (from left) Munashe Jambawo, Kai Goodall and Dino Kingsley-Rizzo with their award-winning GreyCycle Innovation. <b>Photo</b> Je’nine May.
The victorious NextGen Engineers team (from left) Munashe Jambawo, Kai Goodall and Dino Kingsley-Rizzo with their award-winning GreyCycle Innovation. Photo Je’nine May.

A 3D-printed, modular greywater filter, GreyCycle, has won the University of Cape Town’s (UCT) NextGen Engineers team top honours in the RS International Innovators Championship 2023 for young innovators.

The winning trio of Kai Goodall, Munashe Jambawo, and Dino Kingsley-Rizzo are students in the Department of Electrical Engineering. Recognising the pressure on water resources worldwide, their solution targets low-income communities, where greywater can be filtered and recycled again and again for laundry, washing, agriculture and other needs.

The RS Innovators Championship was hosted by RS Group plc, distributors of industrial and electronics products. Teams of young innovators (18 to 30) were invited to design sustainable solutions that aligned with RS Group’s environmental, social and governance goals, as well as the United Nations’ Sustainable Development Goals.

The 10 finalists included teams representing the Philippines (second), the United Kingdom (third), Nigeria, China, Germany, and Rwanda.

The winning team

Goodall is a master’s student specialising in mechatronics. He has a history of social innovation, having designed the Pedal n Spin foot-cranked washing machine, which won an international award in 2021, a Tap and Door Opener Multi-tool to prevent the spread of COVID-19, and an international award-winning essential toolkit, Cirkit. He is also a board member for the Institute of Electrical and Electronics Engineers Engineering Projects in Community Service (EPICS-in-IEEE). His research interests include artificial intelligence, computer vision, education outreach and renewable energy.

Jambawo is also a master’s student in electrical engineering. His research interests include geomagnetically induced currents, power systems, renewable energy, automation, and automotive industries.

Alumnus Kingsley-Rizzo has a Bachelor of Science in Mechatronics. He now works as a software engineer and has experience in full-stack development (end-to-end application software development, including the front end and back end) and working in tech start-ups. His research interests include artificial intelligence, object tracking, computer vision and game design.

Fit for purpose

Greywater, commonly from showers, sinks and washing machines, is under-used, often wasted and disposed of improperly, creating environmental damage and potential health risks, said Goodall.

GreyCycle encourages reuse. It is easy to use, features a 3D-printed modular filter cartridge and the filter layers can be twisted off and easily replaced. Greywater is poured into the top of the device where it is held in a 20-litre bucket. The greywater is then directed through the modular filter cartridge. Each filter cartridge layer contains a natural material (activated carbon, gravel, and silica sand), which slows the flow and traps polluting matter.

The final cartridge contains a micro-membrane filter for microplastic removal, limiting environmental risks. The filtered greywater is then ready for reuse.

The design lends itself to under-resourced, water-poor communities, where access to clean water is a critical issue for millions of people – and poorer communities are disproportionately affected. This is aggravated by the growing effects of climate change, said Goodall.


“The average person produces approximately 100 litres of greywater daily.”

Water collection is also an onerous task for women and children who globally spend a collective 200 million hours each day collecting water, he added.

“And the average person produces approximately 100 litres of greywater daily, which is often disposed of improperly and never reused.”

Sustainable, low maintenance

The product was also rigorously tested to ensure its safety and efficiency. Here the team did field testing in Springfield, a local township, and consulted experts from the City of Cape Town water treatment plant. They then used rapid prototyping to get to their final GreyCycle design, in line with a series of socially responsive projects with UCT’s Associate Professor David Oyedokun.

During the testing, the team worked closely with Tanya Peterson, a township resident, who gave the design a thumbs up.

“I liked how easy it was to use and I look forward to recycling my greywater,” Peterson said.

The results of these field tests showed a significant improvement in the quality of the greywater after filtration, highlighting the potential impact of GreyCycle in communities such as Springfield.

Tanya Peterson with GreyCycle during field testing. Photo Kai Goodall.

Training and mentoring

But innovation was one aspect of the RS International Innovators Competition. Before the virtual final pitch day on 29 March, the shortlisted teams were part of a rigorous six-week masterclasses and mentoring programme, guided by industry experts. Their business mentor was RS Group’s New Ventures development director, Adele Baker.

During the virtual final pitch, the teams presented their ideas to a panel of judges, consisting of experts from RS Group and the Washing Machine Project.


“NextGen Engineers’ pitch was motive, customer-focused, and showcased a well-considered solution with strong evidence of functionality.”

In choosing the UCT team as winners, the judging panel said, “NextGen Engineers’ pitch was emotive, customer-focused, and showcased a well-considered solution with strong evidence of functionality. Great product and slick pitch and team – very convincing. The potential for collaboration with the Washing Machine Project’s Divya in remote communities was also evident."

Kingsley-Rizzo added, “Competing with world-class students from all over the globe was both challenging and inspiring.”

The team also gave their department a thumbs up for its emphasis on a community-focused approach to teaching, learning and research. This has created an environment where socially responsive innovation can thrive among its students, they said.

What’s next?

NextGen Engineers now hope to widen the pool of beneficiaries. There is also scope for corporate partnership opportunities.

“With GreyCycle and our strategic partnerships, we’re changing the world for the better while promoting corporate social responsibility,” said Jambawo.

The group now plans to launch GreyCycle in Cape Town and build three units for further field testing and to improve the product’s efficiency.

Importantly, the GreyCycle system can be integrated with Goodall’s foot-cranked Pedal n Spin washing machine innovation to filter and recycle greywater, enabling a closed-loop system for sustainable water usage.

They also intend on partnering with the Washing Machine Project, bringing their innovation full circle.

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Climate change


The University of Cape Town is an internationally renowned hub for climate change research and training. Our work is a strategic response to urgent knowledge and capacity needs on the African continent – climate change impacts have severe implications for economic and social development, and Africa is particularly vulnerable. Greater expertise is needed to understand the challenges and to design, evaluate and sustain solutions. Engaged research can help society innovate and support effective climate policies and strategies.

This series of articles shows how UCT researchers are working with governments, civil society and the private sector to co-produce knowledge that is impactful, moving us towards a more resilient African society.


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