Binding capacity of humic substances of peats in the relation to petroleum products in the presence of microorganisms of the genus Rhodococcus in aqueous media
M.M. Gertsen, E.D. Dmitrieva
The biotesting method was used to study the effect of humic substances separately and together with oil degrading microorganisms of the genus Rhodococcus on a test object - duckweed in the relation to oil products. The maximum growth of duckweed blades in the presence of humic substances of black alder fen peat is 42%, the minimum - humic substances of sphagnum transition peat 24%. It was found that humic substances of peats can reduce the toxic effect of model pollutants: hexadecane by 3–23%; diesel fuel - 8–40%; oil - 6-16%. The detoxifying ability of humic substances and microorganisms of the genus Rhodococcus in the relation to oil hydrocarbons was determined: the maximum values of the detoxification coefficients of microorganisms Rh. erythropolis S67 and humic substances of reed fen and sphagnum high-moor peat 95–79% and 84–68%; Rh. erythropolis X5 and humic substances of sphagnum high-moor and sphagnum transition peat 82–68% and 71–63%. Humic substances are able to stimulate the growth of oil degrading microorganisms, activating their enzymatic system, thereby contributing to the maximum oxidation of oil hydrocarbons. Due to its surface and biologically active properties, the combined use of humic substances and oil degrading microorganisms can provide environmentally friendly and effective remediation of contaminated water areas.