Ecological State of Haplic Chernozem after Pollution by Oil at Different Levels and Remediation by Biochar

Abstract

One of the most modern and effective methods of soil restoration after pollution is the use of bioremediation. In recent years, special attention has been paid to the use of biochar. However, the ecological state after the introduction of biochar into petroleum-hydrocarbons-contaminated soils at different levels of pollution has been little studied. The work objective was to study the effect of biochar (10% of the soil mass) on the ecological statement of Haplic Chernozem contaminated with different levels of oil, from 0.1 to 50% of the soil mass. To assess the state of Haplic Chernozem after remediation with biochar, indicators of the biological activity of soils were studied. The maximum information content in the case of oil pollution and remediation with biochar was established by the activity of dehydrogenases (r = −0.90) and the total number of bacteria (r = −0.98). When applying biochar, the maximum stimulations of the integral indicator of the biological state (IIBS) relative to the background, by 62, 76, and 72%, were noted in samples with oil at concentrations of 0.5, 25, and 50%, respectively. The results of the study should be used for biodiagnostics and monitoring of the state of oil-contaminated Haplic Chernozem at different levels of contamination after remediation with biochar.