Siberian scientists develop eco-friendly method for deoiling lakes

Researchers from Tomsk State University (TSU) have designed an optimal technology for decontamination of oil fuels from lake ecosystems. As shown experimentally, the content of oil in water is lowered by a factor of 35-40 after application of new purification technique.

The main engineering technologies have been tested during purification works on the lake Shchuchye (Komi Republic), where 157 tonnes of oil have been successfully taken out.

The new method works as follows: a perforated hose is put down to the bed of water reservoir, providing an air jet under surplus pressure to the oil pocket. As a result, the oil goes up to the surface and adheres to the air-water interface. In summer, it is further accumulated in a primary settler and then forwarded to floating basins with sorbents. In winter, it is outputted through the guiding channels laid on the ice.

The technology suggested by TSU is best-suited for the lakes with rock, loam, or sand beddings. In such cases, not only the bottom deposits are extracted, but also the whole water column is decontaminated, meaning no limitations of development to the depth of basin. The method requires no chemicals and could be applied even under winter conditions when the vegetation processes in lakes slow down and the interference in the undersurface life becomes minor.

"In spring and summer, fishes and hydrobionts are actively breeding, pointing out the importance of carrying out any decontamination activity in the cold season," said Danil Vorobiov, one of the main contributors, Doctor of Biological Sciences and director of Institute of Biology of TSU. "One should also bear in mind, that many polluted waters in Russia are located in hard-to-reach areas. Only using winter roads, one could reach them and export the oil elevated from the bed."

• After getting into the water pond, the oil first is accumulated on the water surface, but then gathers mineral particles, losses its floatability and sinks out. There it might retain for decades, killing every living thing, which inevitably lead to the decrease of recreational and fishing importance of a pond. The preliminary experiments of researches have revealed that the newly suggested purification method is capable to stop the above-mentioned negative processes. In several years after deoiling, the number of anomalies in fish evolution has notably decreased.

The Institute of Biology of TSU has got patents of the summer and winter editions of this development. After a series of additional tests, the new technology could be used by oil workers, who already seem to be interested in it. The research data have been published in Water Practice & Technology.
[tass.ru]
13/5/16