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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

Plant scientist, Prof Zakkie Pretorius, contributes to food security with his research
2014-08-26

 
Many plant pathologists spend entire careers trying to outwit microbes, in particular those that cause diseases of economically important plants. In some cases control measures are simple and successful. In others, disease management remains an ongoing battle. 

Prof Zakkie Pretorius, Professor in the Department of Plant Sciences, works on a group of wheat diseases known as rusts. The name is derived from the powdery and brown appearance of these fungi.

Over the course of history wheat rusts have undergone what are notoriously known as boom and bust cycles. During boom periods the disease is controlled by means of heritable resistance in a variety, resulting in good yields. This resistance, though, is more often than not busted by the appearance of new rust strains with novel parasitic abilities. For resistance to remain durable, complex combinations of effective genes and chromosome regions have to be added in a single wheat variety.

In recent years, Prof Pretorius has focused on identifying and characterising resistance sources that have the potential to endure the onslaught of new rust races. His group has made great progress in the control of stripe rust – where several chromosome regions conditioning effective resistance have been identified.

Dr Renée Prins of CenGen and an affiliated UFS staff member, developed molecular markers for these resistance sources. These are now routinely applied in wheat breeding programmes in South Africa. In addition, Prof Pretorius collaborates with several countries to transfer newly discovered stem rust resistance genes to wheat, and in characterising effective sources of resistance in existing wheat collections.

His work is closely supported by research conducted by UFS colleagues, students and other partners on the genetics of the various wheat rust pathogens. These studies aim to answer questions about:
• the origin and relatedness of rust races,
• their highly successful parasitic ability, and
• their adaptation in different environments.

The UFS wheat rust programme adds significantly to the development of resistant varieties and thus more sustainable production of this important crop. 

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