It ensures high efficiency, is cheaper than other methods, and works well in even the most difficult soil conditions. Bioremediation is a technology that will double the amount of creosote oil in the soil in a year. It was developed by scientists from Łukasiewicz – Poznań Institute of Technology, in cooperation with researchers from Poznań University of Technology and Łódź University of Technology.
Olej kreozotowy jest używany do nasycania drewnianych podkładów kolejowych i słupów teletechnicznych. Skutecznie chroni je przed wilgocią czy rozwojem grzybów. Jest jednak wysoce toksyczny dla ludzi i środowiska. Ze względu na zawartość wielopierścieniowych węglowodorów aromatycznych (WWA) zaliczany jest do środków kancerogennych. Z tego powodu jego stosowanie jest mocno ograniczone. Mogą go używać tylko przedsiębiorstwa z odpowiednim pozwoleniem. Autoklawy służące do nasycania drewna są zawsze zlokalizowane na świeżym powietrzu. Gdy powstaje wyciek – zanieczyszczoną kreozotem glebę trzeba oczyścić.
However, this is not easy, because due to the high content of PAHs, creosote does not decompose quickly enough by naturally occurring microorganisms in soil or water.
Many methods are used – often physicochemical, in which the purification process requires energy-intensive stages of pumping air or water. A large part of the methods is so ineffective that it is necessary to transport the contaminated soil to external decontamination piles.
Bioremediation
Researchers from Łukasiewicz – Poznań Institute of Technology, Poznań University of Technology and Łódź University of Technology have developed a new soil bioremediation technology that is effective and cheap.
They used microorganisms grown in bioreactors – bacteria and enzymes obtained from fungi – that transform toxic organic compounds into simpler and harmless substances. Before the scientists selected the composition of the biopreparation, they tested more than a dozen research variants in the laboratory.
The soil they cleared – from the railroad ties saturation plant – had been contaminated for decades. In addition, it was very demanding soil – with high density and water capacity.
- By conducting laboratory scale tests on moderately contaminated soil, we were able to reduce polycyclic aromatic hydrocarbons by 80% within three months. In turn, in technical tests, the PAH content always decreased more than twice in a year.
The developed technology is cheaper than the currently used ones, as it does not require transporting the soil to the decontamination piles. The duration of bioremediation depends on the soil properties, the degree of soil contamination, and the weather. During spring and summer, the purification accelerates, in autumn and winter the microorganisms hibernate and wait for better conditions.
- This technology has been prepared for the most unfavourable soil conditions that can be found in Poland.
Polish saturation plants produce annually approx. 40,000 m³ of wood protected with creosote oil. Researchers at Łukasiewicz – PIT are now working on technology for the disposal of used wooden railroad ties treated with creosote oil. It is estimated that over the next 20-40 years, one and a half million such ties will have to be disposed of in Poland.
