Technologies / Clean-up for water

ENVIRONMENTAL TECHNOLOGIES BY AGROVIT:

Clean-up technologies for water and soil contaminated by oil products,
based on usage of specific water-soluble vitreous biosorbents

At present the contamination of the rivers, seas and oceans with the oil and oil products has reached considerable levels as a result of intense oil production and processing as well as the accidents during transportation and storage. The contaminated aquatic areas increase year by year thus becoming unusable for fishing. Therefore the urgent need in developing the complex biosorbent technology of water reservoir cleanup of oil and oil products is beyond any doubt.

The global experience and expertise in this area favors complex technologies comprising different methods: mechanical, sorbent and biological. The high efficiency of cleaning and biological recovery methods measures can be assured only by optimal combining of different technological procedures based on the detailed analysis of environmental monitoring data and utilization of wide biological variety of degrading microorganisms. The development of hydrophobic natural sorbents for immobilizing the destructing microflora is of particular importance for designing the sorbent-microbiological technologies.

The purpose of our studies was creation of a new type of sorbent with foamed structure that would grant optimal conditions for immobilizing, nutrition and reproduction of the associations of highly active species of the oil-oxidizing microorganisms for substantial period of time.

We have developed a line of sorbents that comprise foamed supercooled fast-tempered melts of metaphosphates with variable element composition including potassium, manganese, calcium, natrium, boron, silicon and microelements. The structure of the foamed vitreous metaphosphate carrier ensures optimal conditions for immobilization and vitality of the microorganisms' cells in the porous medium. At the same time the aeration conditions and the feeding area for the cells substantially increases.

Foamed vitreous metaphosphate serves as the carrier for the oil oxidizing bacteria which keeps them at the water surface, as well as providing mineral nutrition. The composition of the sorbents affects the dissolution rate of the solid foamed carrier in water. The above properties facilitate substantial increase in biological activity of biodegrading bacteria with respect to destruction of oil hydrocarbons and other hydrophobic pollutants. It is worth mentioning that these new sorbents do not increase concentrations of salts in the water reservoirs. Contrary to the traditional polycrystalline fertilizers the vitreous metaphosphates dissolve slowly and do not disrupt the natural trophic links in the water ecosystem.

Our studies demonstrated high practical value of the foamed phosphate glasses as sorbents for immobilizing of microorganisms and formed the basis for creation of efficient technologies for cleaning the environment from oil products and other hazardous xenobiotics.

The application of new AVALON biosorbent ensures high efficiency of the process of oil products biodestruction in the ground and in the water (79,6-94,9%), as the immobilization of the oil oxidating microorganisms at foamed metaphosphates increases the time span of their operation in the environment by a factor of 3-4, which, in turn, provides for active biodestruction process without additional biopreparation input. Providing abiogenic microflora with the mineral nutrition increases the efficiency of the environment cleaning from technogenic contamination and restoration of the trophic links damaged by this contamination.

In conclusion, the main and principal advantages of our technology compared to the existing ones are:

The possibility of nearly complete deletion of the oil spill remnants in the form of low solubility films from the surfaces of aquatic areas
Not necessary to input additional nutrition for the degrading microorganisms during the process of biorecovery
Low cost
Environmentally friendly technology