Harnessing the goodness gas

When the dreaded disease, meningitis, broke out at the University of Potchefstroom recently, Vice-Chancellor Theuns Eloff immediately called in the ‘ozone squad” to deal with the emerging crisis.

Professor at the unit for space physics (USP) at Potchefstroom University Okkie de Jager, along with his team, immediately began to set up ozone generators in spaces where the deadly bug was suspected to be lurking.

De Jager had just unleashed nature’s most potent steriliser. ‘Ozone is a natural gas that is inhaled on a daily basis,” he says. ‘Yet it has a wonderful power to protect us from our unseen enemies.”

Ozone occurs readily in nature, usually as a result of lightning strikes. That smell of fresh, clean, spring rain after a storm most often results from nature’s creation of ozone. It kills 99% of bacteria, viruses and fungi on contact.

‘Each ozone molecule is made up of three oxygen atoms,” says De Jager. ‘Once generated it is quite unstable. One of the atoms splits off and attaches itself to any particle or pollutant with which it comes into contact. That single oxygen atom proceeds to oxidise the particle, which is then no longer toxic or — if it’s biological — no longer able to reproduce. The only by-product of this process is pure, clean oxygen.”

Scientists refer to ozone as ‘nature’s antibiotic” because it helps to maintain a clean and safe environment.

‘When ozone is used to clear the air of bacteria, or water of germs, no residues are left behind that are unhealthy for humans, as in the case of chemicals,” says the professor. ‘It can dramatically reduce pollution, contamination and infectious airborne bacteria and viruses.”

The underrated steriliser even neutralises cigarette smoke, which contains about 3 600 different chemicals. When exposed to ozone these are reduced to a harmless, basic molecular structure.

Ozone is also used to extend the shelf life of food and is a human therapy throughout the world.

Since the early 1900s it has been used in water purification, where it reacts about 3 200 times faster than chlorine. Many swimming-pool owners are switching to ozone in place of chlorine. Ozone’s popularity as an environmentally friendly way to treat drinking water and air pollution has led to a large and rapidly-growing global market for ozone generators.

The gas can be created on demand. An ozone generator uses the oxygen produced by the Earth’s plant life and the high-frequency corona discharge to produce ozone, just as lightning does during a thunderstorm. Harnessing this principle is the most powerful way man has to create activated oxygen, or ozone.

De Jager and his team were nominated for a Technology and Human Resources for Industry Programme (Thrip) award for their study of the usefulness of ozone and have patented techniques and equipment they believe will be viable in a competitive market. They use technology that strips an electron from an oxygen molecule before coulomb collisions (a by-product of the process of manufacturing ozone) proceed.

‘Coulomb collisions normally result in unwanted energy losses, which explains the problem of efficiency lacking in most ozone generators,” said De Jager.

‘The advantages of the Potchefstroom University ozone generators are that they are lightweight, competitively priced, compact and have low power consumption but high efficiency. And they are environmentally friendly,” he says.

Three models of ozone generators and an ozone detector have already been tested for the international market, and several thousand units were produced last year as samples. The first model has already received the necessary certifications required for the European and Australian markets. Mass production and export can now begin in earnest.

‘The next step is to obtain the required rating for the much larger United States market. Substantial orders have already been placed by a few general dealers,” says De Jager. The units are being made by a local company called Ozone Assembly, which was set up by the university and its industrial partner Sterizone for this purpose. Internet entrepreneur and cosmonaut Mark Shuttleworth’s company HBD has shares in the company.

‘Product demand from international clients is expected to stretch the production capability of South African industries, given the advanced technology involved,” says De Jager.

The team’s latest breakthroughs include a new class of sub-nanosecond-switching insulated gate devices that control the outflow of ozone into the atmosphere.

The Occupational Health and Safety Act prescribes an upper-limit human exposure of 0,1 parts ozone per million parts air over eight hours. ‘We need a programmable timer to control the ozone output to provide sufficient disinfection,” says De Jager. ‘The timer [controls] bacteria and virus concentrations according to the individual’s needs.”

De Jager says the technology developed to achieve the breakthrough for insulated gate devices should lead to a significant improvement in switching-mode power supplies, such as those used for laptop computers.