Purification of tap water and oceans

Cleaning ballast water has a major impact on the global ocean environment. Photo: Sjöfartsverket, Niklas Liljegren

Advanced research for just over a decade lies behind Wallenius Water’s water purifiers. Without the use of chemicals, the technology purifies the water in kitchen taps, swimming pools and oceans of harmful micro-organisms and other undesirable substances.

Wallenius Water’s story began in its fellow subsidiary, the shipping company Walleniusrederierna. A plan was presented in the mid-1990s to gradually reduce the environmental impact of vessels. One of the focus areas was to find a method of purifying their ballast water without creating new environ-mental problems. Shipping uses up to five billion tonnes of ballast water per year. This water is used to stabilise cargo vessels. The ballast water may contain contaminants and foreign species that risk multi- plying and replacing natural ecosystems if the water is emptied without having been purified.

From ballast water....

Intensive work was begun to develop a purification method that met the tough requirements of the UN’s International Maritime Organization, IMO. The project was implemented with one of the biggest suppliers in the maritime industry, Alfa Laval, and resulted in PureBallast, the first IMO-approved, chemical-free product for purifying ballast water.
The technology has since been installed in numerous vessels around the world. However, it has yet to enjoy a full international break-through. The reason for this is partly to be found in the regulations for international shipping.

– Although the IMO classifies un-purified ballast water as a major global threat to the environment, the convention that was supposed to force vessels to purify their ballast water has not been ratified by enough countries for it to enter into force, says Torkel Elgh, the Wallenius Water CEO. purification on a broad front

In parallel with the development of technology for purifying ballast water, the Wallenius company developed a number of other products based on the same technology. This is Wallenius AOT (Advanced Oxidation Technology); patented, chemical-free technology inspired by the way in which nature itself purifies water. A light source and a catalytic surface are used to create free radicals that break down harmful microorganisms and other undesirable substances in the water without harmful residual  products being produced.

The purification technology can be used for both small quantities of water and large volumes of thousands of cubic metres of water. As the technology makes it possible to recycle the water, it has a positive impact on both energy consumption and profitability. One of the beneficiaries is industry, where large volumes of water are often consumed.

In showers and swimming pools

Another area of application is the property sector, where chemicals or heat are frequently used to keep water free of microorganisms. The Legionella bacterium, which causes Legionnaires’ disease and Pontiac fever, is a common problem in this connection. Bacteria can be spread via showers and similar installations where there is water mist. Wallenius AOT allows the temperature in the hot water system to be turned down, thus reducing the Legionella bacteria to a minimum.

A practical example of how the technology works can be seen at the swimming pool in Sundbyberg, which was able to reduce the use of chemicals and thus the bound chlorine by 70 per cent. At the same time, both water and energy consumption have decreased. Less chlorine consumption has also contributed to a better working environment for the staff.

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