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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

Student excels at international level with research in Inorganic Chemistry
2015-09-21


Carla Pretorius is currently conducting research in
Inorganic Chemistry at the St Petersburg University,
Russia.

Photo:Supplied

Carla Pretorius completed her PhD in Inorganic Chemistry recently, with a thesis entitled “Structural and Reactivity Study of Rhodium(I) Carbonyl Complexes as Model Nano Assemblies”, and has just received her results. The assessors were very impressed, and she will graduate at the next UFS Summer Graduation in December 2015.

She is currently conducting research in St Petersburg, Russia, by invitation. She is working in the group of Prof Vadim Kukushkin of the St Petersburg University, under a bilateral collaboration agreement between the groups of Prof Kukuskin (SPBU) and Prof André Roodt (Head of the Department of Chemistry at the UFS).

Her research involves the intermetallic rhodium-rhodium interactions for the formation of nano-wires and -plates, with applications in the micro-electronics industry, and potentially for harvesting sun energy. She was one of only three young South African scientists invited to attend the workshop “Hot Topics in Contemporary Crystallography” in Split in Croatia during 2014. More recently, she received the prize for best student poster presentation at the international symposium, Indaba 8 in Skukuza in the Kruger National Park, which was judged by an international panel.

Carla was also one of the few international PhD students invited to present a lecture at the 29th European Crystallographic Meeting (ECM29) in Rovinj, Croatia (23-28 August 2015; more than 1 000 delegates from 51 countries). As a result of this lecture, she has just received an invitation to start a collaborative project with a Polish research group at the European Synchrotron Research Facility (ESRF) in Grenoble, France.

According to Prof Roodt, the ESRF ID09B beam line is the only one of its kind in Europe designed for time-resolved Laue diffraction experiments. It has a time-resolution of up to one tenth of a nanosecond, after activation by a laser pulse 100 times shorter (one tenth of a nanosecond when compared to one second is the equivalent of one second compared to 300 years). The results from these experiments will broaden the knowledge on light-induced transformations of very short processes; for example, as in photochemical reactions associated with sun energy harvesting, and will assist in the development of better materials to capture these.

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