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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

Fire as a management tool questionable in arid and semi-arid grassland areas
2015-03-24

Wild fire in the grassland
Photo: Supplied


The influence of fire on the ecosystem in the higher rainfall ‘‘sour’’ grassland areas of southern Africa has been well established. However, less information is available for arid and semi-arid ‘‘sweet’’ grassland areas, says Prof Hennie Snyman, Professor in the Department of Animal, Wildlife, and Grassland Sciences, about his research on the short-term impact of fire on the productivity of grasslands in semi-arid areas.

Sour and sweet grassland areas can be defined as receiving either higher or lower than approximately 600 mm of rainfall respectively. In quantifying the short-term impact of fire on the productivity of grasslands in semi-arid areas, a South African case study (experimental plot data) was investigated.

“Burned grassland can take at least two full growing seasons to recover in terms of above- and below-ground plant production and of water-use efficiency (WUE). The initial advantage in quality (crude protein) accompanying fire does not neutralise the reduction in half of the above-ground production and poor WUE occurring in the first season following the fire.

“The below-ground growth is more sensitive to burning than above-ground growth. Seasonal above-ground production loss to fire, which is a function of the amount and distribution of rainfall, can vary between 238 and 444 kg ha -1 for semi-arid grasslands. The importance of correct timing in the utilisation of burned semi-arid grassland, with respect to sustained high production, cannot be overemphasised,” said Prof Snyman.

In arid and semi-arid grassland areas, fire as a management tool is questionable if there is no specific purpose for it, as it can increase ecological and financial risk management in the short term.

Prof Snyman said: “More research is needed to quantify the impact of runaway fires on both productivity and soil properties, in terms of different seasonal climatic variations. The information to date may already serve as valuable guidelines regarding grassland productivity losses in semi-arid areas. These results can also provide a guideline in claims arising from unforeseen fires, in which thousands of rands can be involved, and which are often based on unscientific evidence.”

For more information or enquiries contact news@ufs.ac.za

 

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