Treating oily water: Efficiency exceeds requirements 10 times

Although the regulations slightly vary from country to country, mainly in Europe and America oil discharge in water must meet 5mg/L for discharges to surface water drains and the water environment. Although marine life can survive this degree of pollution, the oil products pass into organisms affecting their health and transferring toxic substances further into ecosystem.

"After treatment with our technology the wastewater from oil industries released into the sea not only meets legal requirements, but is virtually clean," says Associate Professor Viktoras Račys, researcher at KTU Faculty of Chemical Technology.

Biological wastewater treatment technology developed at KTU employs microorganisms, which can adapt to certain environment and synthesise ferments to "digest" oil products turning them into CO₂ and H₂O. The technology has been successfully implemented in Lithuanian oil transfer company Klaipėdos Nafta. At the moment, it is being modified to be used in other areas of activity potentially connected to organic contamination, such as food, chemical, agricultural production industries.

According to KTU researcher, the essential challenge is to ensure the stability of microorganisms used for water treatment technology: it is very difficult to cultivate them and very easy to lose.

"Our secret is that we have found out a way of keeping those microorganisms in the system, so they don't leave. Thanks to this, our technology is very stable and very reliable, basically indestructible," says Viktoras Račys.

The currently working KTU-invented technology cleans 160 m3 per hour. It is ready to use in sensitive environmental regions, for the treatment of oil production and refinery wastewater, ballast water, the run-off from car washes and car parks and any petroleum polluted wastewaters containing both legally regulated compounds and the most toxic or persistent compounds.