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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

Professor triumphs at Water Research Commission (WRC) Symposium
2013-12-13

 
Prof Leon van Rensburg

The university’s advancement of research excellence recently found further embodiment in Prof Leon van Rensburg from the Department of Soil- and Crop- and Climate Sciences. His expertise in the water sector resulted in award-winning research.

Prof Van Rensburg received the award for Sustainable Development Solutions 2013 at the Water Research Commission (WRC) Symposium held at the CSIR in Pretoria. The symposium acknowledged local scientific solutions that have had a global impact. Prof Van Rensburg was recognised for his outstanding research guiding the management of salinity under irrigation at farm level in South Africa – ensuring food production. The paper that earned him this honour is entitled “Rainwater harvesting and conservation practices: challenges and opportunities for sustainable land and water use of ‘The Green Village’ in arid to semi-arid climate zones.”

The awards were linked to the WRC’s newly-adopted corporate planning tool named the ‘Knowledge Tree’, guiding the commission’s operations. The ‘Knowledge Tree’ functions as a yardstick with which the WRC measures its impact in essential areas. The presentation of these accolades underscored the importance of water science and water technology in improving the daily reality of people at grassroots level.

Prof Van Rensburg’s research goal is to enhance the efficiency of water usage of crop production systems in both the dryland and irrigation sectors. Part of his latest achievements include being editor for a special edition of the Irrigation and Drainage Journal (2012; vol 61) on rainwater harvesting.

Prof Chris du Preez, co-author of the winning paper, is an expert on soil quality, especially organic matter. He serves as the Head of the Department of Soil, Crop and Climate Sciences and has also acted as President of the Soil Science Society of South Africa. His current research focuses on agricultural land use and soil organic matter changes, soil fertility and fertilisation, and agriculture water quality and usage.

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