Influence of dynamic action on biodegradation of hydrocarbons in soil

Abstract

Petroleum and petroleum products, due to high adsorbing ability of soil, long time remain in it, changing its physical, chemical and biological properties. Restoration of soil fertility after mineral oil influence under natural conditions lasts tens years. We had been developed the laboratory bioreactor for studying of process of biodegradation of the petro-polluted ground in dynamic conditions. The bioreactor represents the cylindrical device on the mobile platform equipped with a dynamometer for measurement of a jet twisting moment. The device is equipped by the mechanical mixing device and an adjustable drive, and as the compressor and rotameter for measurement of the expense of air. As a test-culture of microorganisms Candida maltosa strain №569 was used which are a part of a biological product "Oleovorin" (firm "Bigor"). For researches was it is taken "Universal" neutral soil. As the previous experiences have shown that petrooxidizing microorganisms brought by us enter difficult interactions with autochthonic microflora, for cleanliness of experiment soil sterilized twice within an hour at temperature 121ºС. To exclude influence of structure of oil on biodegradation parameters, the further experiences were spent on paraffin. The soil was polluted by paraffin С14-С17. Soil mixed with the help propeller mixer with various speed of rotation. Control experiments were carried out by placing of identical quantity of a ground in the capacity equal to diameter of the bioreactor. The control capacity was in the same temperature conditions, as the bioreactor. The greatest difference between speeds of consumption in a static and dynamic mode is observed till 20 o'clock, speed in a dynamic mode exceeded speed of consumption of hydrocarbons in a static mode approximately in several times. By means of hashing of the soil polluted by hydrocarbons it is possible to lower sharply concentration of hydrocarbons within the first 20 hours, and further dynamic process provides much lower maintenance of hydrocarbons in soil.