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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

UFS researcher engineers metal surfaces
2015-03-03

Shaun Cronjé, a PhD student, in a surface characterisation laboratory at the UFS.

It is well known that the surface of a component is much more vulnerable to damage than the interior, and that surface-originated degradation such as wear, corrosion, and fracture will eventually destroy the component.

“Engineering the surface, based on scientific knowledge, is essential to control these damaging processes. It also creates electronic and geometric structures on the surface which opens up a world of new devices, especially considering the properties on the nano-length scale,” said Prof Wiets Roos from the Department of Physics at the University of the Free State (UFS).

At elevated temperatures, atoms are more mobile and can migrate to grain boundaries and surfaces, which have a major influence on material properties. The redistribution of solute atoms between the surface and the bulk of the material is known as segregation. Knowing the behaviour of segregation at the surface/environment interface can be very useful in the development of new materials. As an example materials can be improved higher efficiency and lower fuel consumption, thus reducing environmental pollution.

The main aims of Prof Roos’s research are to understand surface segregation, use it as a tool, and contribute to the various surface engineering fields.

The surface characterisation laboratories at the UFS are well equipped to do high temperature segregation measurements, and have already proven a success, not only in the ability to prepare the specimens for characterisation, but also in developing models and procedures to quantify the segregation parameters.

The most recent results have demonstrated the importance of taking evaporation into account during quantification.” This has laid the foundation for future studies by installing the necessary hardware in a surface characterisation spectrometer, establishing experimental protocols, and improving an existing model (developed in this laboratory) for simulating segregation profiles,” said Prof Roos.

Segregation parameters allow the researcher to predict and utilise the surface concentration behaviour as a function of temperature and time. “This not only contributes to fields involving corrosion, oxidation, sintering, wear, chemical poisoning, powder metallurgy, and lubrication but adds to the development of self-healing devices,” said Prof Roos.

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