The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substances

Abstract

Removal of petroleum products from contaminated soil is a long-term process requiring attention and constant monitoring. The aim of this study was to determine the effect of Fyre-Zyme enzyme preparation and/or calcium carbonate on microbiological changes and conversion of n-aliphatic hydrocarbons in soil contaminated of petroleum-derived substances. The material for testing was soil contaminated with petroleum substances. The total concentration of n-alkanes with a C8–C40 chain length was 420.1 mg·kg−1 DM. The pot tests were carried out by introducing stimulators. As a decomposition promoter for n-alkanes in contaminated soil, a 6% water solution of Fyre-Zyme and/or 1% sterile CaCO3 was used. The pots were incubated at 25 °C for 21 days. The dynamics of changes in the microbiota and concentration of n-alkanes were controlled for 21 days, every 7 days taking soil for testing. Microbiological tests included determining the total number of bacteria and fungi. Chemical analysis was performed by chromatographic method. Stimulating of soil bioremediation of contaminated hydrocarbons with calcium carbonate increased the number of bacteria, and stimulation with Fyre-Zyme and calcium carbonate—the number of filamentous fungi. There was no significant correlation between the concentration of n-alkanes in the soil and the total number of bacteria and fungi but stimulating of soil bioremediation with calcium carbonate increased the number of bacteria, and stimulation with Fyre-Zyme and calcium carbonate—the number of filamentous fungi. The observed correlations indicate that the concentration of n-alkanes in the contaminated soil increases with the addition of Fyre-Zyme.