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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

Harvard couple to present lectures on Biostatistics and Mathematics at the UFS
2015-12-07


Professor Donald Rubin

Prof Donald Rubin (John L. Loeb Professor of Statistics at Harvard University) and Elizabeth Zell (MStat - mathematical statistician in the Division of Bacterial Diseases) will visit the University of the Free State (UFS) where they will present lectures on their respective work.

Over his prestigious academic career, Prof Don Rubin’s 400 publications and 13 books have earned him around 180 000 citations at an h-index of 113. He is one of the most cited statisticians/mathematicians/economists/psychologists in the world over the last 10 -15 years. He has supervised 35 PhD candidates as sole-supervisor, 17 more as co-supervisor, with a further eight in the pipeline.

Prof Rubin who will meet with UFS academics in the Department of Mathematics and Actuarial Sciences will also deliver a lecture: Rerandomisation to improve covariate balance in experiments.

Randomised experiments are the “gold standard” for estimating causal effects, yet in practice, chance imbalances often exist in covariate distributions between treatment groups. If covariate data are available before units are exposed to treatments, these chance imbalances can be mitigated by first checking covariate balance before the physical experiment takes place. Provided a precise definition of imbalance has been specified in advance, unbalanced randomisations can be discarded, followed by a rerandomisation. This process can continue until a randomisation yielding balance according to the definition is achieved. By improving covariate balance, rerandomisation provides more precise and trustworthy estimates of treatment effects.

Prof Rubin received an honorary professorship from the Faculty of Natural and Agricultural Sciences at the UFS.


Elizabeth Zell

The lecture will take place on:
Date: Tuesday 8 December 2015
Time: 16:00
Venue: Albert Wessels Auditorium, Bloemfontein Campus

Zell earned her Master’s degree in Statistics at North Carolina State University, and for more than two decades, was an active bio-statistical researcher in various offices of the Centers for Disease Control (CDC). Since 2013, she has been the Principal Statistician and President of Stat-Epi Associates, Inc. Her 150+ publications have earned her 14 500 citations at an h-index of over 50. She is a Fellow of the American Statistical Association, and, in 2010, she received the Statistics Section Government Award for outstanding contributions to statistics and public health by the American Public Health Association. During her career at the CDC, she earned more than 20 CDC research awards and honours.

She will deliver two lectures at the UFS. The first is entitled A Potential Outcomes Approach to Documenting the Public Health Impact of the Introduction of PCV13 for the Prevention of Invasive Pneumococcal Disease. The topic of her second lecture is: Assessing the Effectiveness of Intrapartum Antibiotic Prophylaxis for Prevention of Early-Onset Group B Streptococcus Disease through Propensity Score Design

Elizabeth’s lectures will take place on:
Date: Wednesday 9 December 2015
Time: 10:45 and 13:00
Venue: West Block 111, Bloemfontein Campus

For more information, please contact Dr Michael von Maltitz at VMaltitzMJ@ufs.ac.za.

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