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23 November 2021 | Story Leonie Bolleurs | Photo Tania Allen
Dr Jana Vermaas and Ketshepileone Matlhoko are working on research that leaves your washing clean and fresh without the use of any detergents, which is also beneficial to the environment.

Cold water or hot water? Omo or Skip? Laundry blues is a reality in most households and when you add stains to the equation, then what was supposed to be part of your weekly household routine, becomes frustrating and time consuming. 

Researchers at the University of the Free State (UFS) are conducting research that is putting a whole new environmentally friendly spin on laundry day.

Sustainability and environmental conservation

Dr Jana Vermaas, Lecturer in the Department of Sustainable Food Systems and Development at the UFS, is passionate about textiles and sustainability – almost a decade ago, she conducted a study on the efficacy of anolyte as a disinfectant for textiles.

She describes the process: “During electrochemical activation, a dilute solution of natrium chloride/salt passes through a cylindrical electrolytic cell where the anodic and cathodic chambers are separated. Two separate streams of electrochemically activated water are produced. Anolyte as water was produced at the positive electrode and has a low pH, high oxidation-reduction potential and contains dissolved chloride, oxygen, and hydroxyl radical. It also has an antimicrobial effect.”

The benefits of this process are in line with her enthusiasm for environmental conservation. 

According to Dr Vermaas, the amount of water and chemicals used to clean textile articles is massive. “Chemicals used to disinfect, for example, hospital laundry, are hazardous. Not all laundries in the industry have a closed loop system or try to remove the chemicals before the wastewater is discarded.”

“Different amounts of detergents have various effects on our fauna and flora. Due to their low biodegradability, toxicity, and high absorbance of particles, detergents can reduce the natural water quality, cause pH changes in soil and water, lead to eutrophication (too many nutrients), reduce light transmission, and increase salinity in water sources.”

“But with the catholyte and anolyte process, water returns to its original status, which means that the water solution becomes inactive again after production where it existed in a metastable state while containing many free radicals and a variety of molecules for 48 hours. Thus, no chemicals are left in the wastewater. The water can therefore be recycled, not as potable water but, for example, to flush toilets or to water plants.

“We should do what we can to save water,” she says. 

Should you, like Dr Vermaas, also feel strongly about protecting the environment and want to obtain one of these machines that leaves your washing clean and fresh without the use of any detergents, you will be able to find such an appliance in South Arica. However, it does not come cheap. “It is a bit costly for residential use, but might be more accessible in the future,” states Dr Vermaas, who is of the opinion that it is a more sustainable option for commercial laundries.

Detergency properties and colourfastness 

Recently, more research has been conducted on this topic, but with a focus on the detergency properties of the catholyte to clean different textile fibres (natural and synthetic). Catholyte, she explains, is water produced at the negative electrode with a high pH, low oxidation-reduction potential, containing alkaline minerals. It also has surface active agents that increase the wetting properties, and it is an antioxidant. 

“A master’s student in the department, Ketshepileone Matlhoko, will be submitting her dissertation at the end of November on the possibility of using the catholyte as a scouring agent to clean raw wool,” says Dr Vermaas. 

The department is also conducting studies to investigate the influence of both catholyte and anolyte on colourfastness.

*Graphic: Production of electrolysed water (Nakae and Indaba, 2000). Diagram: Supplied



News Archive

Eye tracker device a first in Africa
2013-07-31

 

 31 July 2013

Keeping an eye on empowerment

"If we can see what you see, we can think what you think."

Eye-tracking used to be one of those fabulous science-fiction inventions, along with Superman-like bionic ability. Could you really use the movement of your eyes to read people's minds? Or drive your car? Or transfix your enemy with a laser-beam?

Well, actually, yes, you can (apart, perhaps, from the laser beam… ). An eye tracker is not something from science fiction; it actually exists, and is widely used around the world for a number of purposes.

Simply put, an eye tracker is a device for measuring eye positions and eye movement. Its most obvious use is in marketing, to find out what people are looking at (when they see an advertisement, for instance, or when they are wandering along a supermarket aisle). The eye tracker measures where people look first, what attracts their attention, and what they look at the longest. It is used extensively in developed countries to predict consumer behaviour, based on what – literally – catches the eye.

On a more serious level, psychologists, therapists and educators can also use this device for a number of applications, such as analysis and education. And – most excitingly – eye tracking can be used by disabled people to use a computer and thereby operate a number of devices and machines. Impaired or disabled people can use eye tracking to get a whole new lease on life.

In South Africa and other developing countries, however, eye tracking is not widely used. Even though off-the-shelf webcams and open-source software can be obtained extremely cheaply, they are complex to use and the quality cannot be guaranteed. Specialist high-quality eye-tracking devices have to be imported, and they are extremely expensive – or rather – they used to be. Not anymore.

The Department of Computer Science and Informatics (CSI) at the University of the Free State has succeeded in developing a high-quality eye tracker at a fraction of the cost of the imported devices. Along with the hardware, the department has also developed specialised software for a number of applications. These would be useful for graphic designers, marketers, analysts, cognitive psychologists, language specialists, ophthalmologists, radiographers, occupational and speech therapists, and people with disabilities. In the not-too-distant future, even fleet owners and drivers would be able to use this technology.

"The research team at CSI has many years of eye-tracking experience," says team leader Prof Pieter Blignaut, "both with the technical aspect as well as the practical aspect. We also provide a multi-dimensional service to clients that includes the equipment, training and support. We even provide feedback to users.

"We have a basic desktop model available that can be used for research, and can be adapted so that people can interact with a computer. It will be possible in future to design a device that would be able to operate a wheelchair. We are working on a model incorporated into a pair of glasses which will provide gaze analysis for people in their natural surroundings, for instance when driving a vehicle.

"Up till now, the imported models have been too expensive," he continues. "But with our system, the technology is now within reach for anyone who needs it. This could lead to economic expansion and job creation."

The University of the Free State is the first manufacturer of eye-tracking devices in Africa, and Blignaut hopes that the project will contribute to nation-building and empowerment.

"The biggest advantage is that we now have a local manufacturer providing a quality product with local training and support."

In an eye-tracking device, a tiny infra-red light shines on the eye and causes a reflection which is picked up by a high-resolution camera. Every eye movement causes a change in the reflection, which is then mapped. Infra-red light is not harmful to the eye and is not even noticed. Eye movement is then completely natural.

Based on eye movements, a researcher can study cognitive patterns, driver behaviour, attention spans, even thinking patterns. A disabled person could use their eye-movements to interact with a computer, with future technology (still in development) that would enable that computer to control a wheelchair or operate machinery.

The UFS recently initiated the foundation of an eye-tracking interest group for South Africa (ETSA) and sponsor a biennial-eye tracking conference. Their website can be found at www.eyetrackingsa.co.za.

“Eye tracking is an amazing tool for empowerment and development in Africa, “ says Blignaut, “but it is not used as much as it should be, because it is seen as too expensive. We are trying to bring this technology within the reach of anyone and everyone who needs it.”

Issued by: Lacea Loader
Director: Strategic Communication

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