New Biological Means for the Remediation of Oil-Contaminated Soil

Abstract

The All-Russian Scientific Research Institute of Reclaimed Lands has developed organic solid-phase biologic means for crop production and agriculture – multi-purpose compost (KMN) and fermentation product (PF). A characteristics of KMN and PF allows them to be use for bioremediation of oil-contaminated soil as activators of the native microflora and as sorbents of strains of oil destructive microorganisms. As source of oil destructing microorganisms the MikroBak preparation was used. Suspensed MikroBak was added to the PF and KMN in the process of their production – at the stage of ripening, based on the final content of oil destructors in the soil 105 CFU / 1 g of soil. It was established that three days after the MikroBak introduction, samples of solid-phase biological means had the highest microbiological activity, in particular, the number of microorganisms utilizing oil increased 2.5–7.5 times. To study the effectiveness of new biological means for remediation of oil-contaminated soils, a model experiment lasting 4 months was laid. Sod-podzolic light loamy soil was artificially contaminated with oil at the rate of 5 % of oil pollution, taking into account the mass of applied biological means. New biological means, prepared both on the basis of PF and MikroBak, and on the basis of KMN and MikroBak, combine two methods of bioremediation – stimulation of native microorganisms and the introduction of active microorganisms-destructors. After 2 weeks from the start of the experiment, the greatest destruction of oil was revealed in the variants using new biological means based on KMN and MikroBak, as well as PF and MikroBak – 29.8 and 24.3 %, respectively. In a month, the maximum destruction was observed in the variant with the use of the MikroBak – 36 %. At the end of the experiment, the degree of oil destruction and the number of microorganisms utilizing crude oil were in a linear relationship, the correlation coefficient r = 0.76. It was established that the use of the MikroBak biopreparation at the stage of maturation of the PF contributed to obtaining the most optimal, effective biological mean, which in 4 months provided a degree of oil destruction of 60.6 %.