STUDY OF OIL DEGRADATION IN OIL-CONTAMINATED SOIL DURING PURIFICATION USING A BIOLOGICAL PRODUCT

Abstract

During a scientific study, a laboratory experiment was conducted to investigate the degradation of oil by various microorganisms in a liquid mineral medium containing 2% oil. This experiment was conducted at temperatures of 24ºC and 5ºC for a duration of 10 days. Using infrared spectroscopy (IR spectroscopy), the degree of oil decomposition by each microorganism was determined. Based on these data, four associations of microorganisms were created, which proved to be effective in breaking down oil hydrocarbons. Using gravimetry and IR spectrometry, the degree of oil biodegradation by these microorganism associations was assessed, ranging from 30% to 70%. Based on the data obtained regarding microbial associations, a new bio-preparation was developed, containing the Pseudomonas sp. K3-H strain and two Rhodococcus strains (F2/2-Н4, F2/1-Н4). Subsequently, fieldwork was conducted on the premises of oil waste of the company "TOO Company – Daulet Asia." Over a period of 12 weeks, the population of oil-degrading microorganisms at the oil-contaminated site reached the required level, resulting in an 89.67% reduction in the amount of oil. It is worth noting that the ambient temperature varied from 05 to 39°C during the day and from 0 to 24°C at night during this period. The results of the field studies demonstrated the effectiveness of the developed bio-preparation based on the Rhodococcus erythropolis KZ1, Rhodococcus erythropolis KZ2, and Pseudomonas putida KZ3 strains. Thus, the proposed bioremediation strategy utilizing the developed bio-preparation successfully passed the testing phase at the landfill of "TOO Company - Daulet Asia" in the Kyzylorda region of the Republic of Kazakhstan.