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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

Prof Hendrik Swart richly contributes to research of phosphors
2014-12-02

Prof Hendrik Swart
Photo: Merwelene van der Merwe

Since his appointment as the South African Research Chairs Initiative (SARChI) Chair, there has been a sharp increase in the number of papers and publications by Prof Hendrik Swart, Senior Professor in the Department of Physics at the University of the Free State (UFS). From January this year, he has already published 78 articles. Some of the journals that has published his work, includes:

• Nanotechnology (impact of 3.67)
• Dalton Transactions (impact of 4.097)
• Sensors and Actuators B: Chemical (impact 3.84)

“My biggest success, however, is the powerful group of researchers we have built over the years. Staff, postdocs and students – without them it would have been impossible. I am therefore much indebted to my groups on both the Bloemfontein and Qwaqwa Campuses.

“The good apparatus we acquired via a sponsorship from the National Research Foundation and Sasol is also one of the main reasons for this. The financial support I get from the university’s research office is of course also a contributing factor,” he says.

For the past 20 years, Prof Swart has been conducting research on any substance that glows. “I only adjust the focus to fit in with current trends,” he says.

Prof Swart believes that his research will make a contribution to the fundamental knowledge about phosphors, as well as to the training of good students for the academic and industrial world on the outside. For the man on the street, his research translates into better, brighter lights that use less energy.

His more recent research focuses on the development of nano-phosphors for light-emitting diodes (LEDS) and organic light-emitting diodes (OLED).

Prof Swart has presented papers on his research not only nationally, but all over the world – including countries in Europe and the East. Some of the most recent papers presented by him and his colleagues/postgraduate students include:

• Applications of AES, XPS and TOF SIMS to phosphor materials at die 15th European Conference on Applications of Surface and Interface Analysis 2013 in Forte Village Resort, Sardinia, Italy.
• Luminescent properties of phosphor nano thin films at the first International Symposium on Nanoparticles/Nanomaterials and Applications in Caparica (Lisbon, Portugal), where he was an invited speaker.
• Role of surface and deep-level defects on the emission of nano metal oxides at the 2014 NanoAfrica international conference, Vanderbijlpark, South Africa, where he delivered the keynote address.
• PHI systems and their modifications at KOVSIES at the PHI European User Meeting in Ismaning (Munich), Germany, where he was invited to speak.

Prof Swart also delivered the keynote address at the SETCOR International Conference on Smart Materials and Surfaces in Bangkok, Thailand. His lecture was titled, ‘Role of surface and deep-level defects on the emission and degradation of phosphor materials’.

 

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