Petroleum hydrocarbons are the most ubiquitous organic pollutants. In Europe, 45% of polluted habitats are contaminated with these compounds. These observations have prompted a pot experiment aiming to determine the effectiveness of a molecular sieve, alginite, sepiolite and the Ikasorb 1850 sorbent (0 and 15 g kg-1 D.M. soil) in remediating soil contaminated with Verva diesel oil (10 cm3 DO kg-1 D.M. soil). Soil contamination with diesel oil significantly inhibited the growth and development of maize and modified the chemical composition of this crop. Diesel oil decreased the bioconcentration index of nitrogen, phosphorus, calcium and potassium in maize. The molecular sieve, sepiolite, alginite and sorbent minimized the adverse effects of diesel oil on the aerial parts and roots of maize plants. Diesel oil disrupted the microbial equilibrium in soil, and it decreased the ecophysiological diversity of fungi and organotrophic bacteria. Diesel oil decreased the percentage of Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria in the bacterial community, stimulated intracellular and extracellular enzymes, and exerted adverse effects on the physical properties of soil. The evaluated soil remediation agents exerted varied effects on the microbiome of contaminated soil. Sepiolite, alginite and Ikasorb generally enhanced the growth of actinomycetes by increasing the proportion of K-strategists in soil. All remediation agents increased the ecophysiological diversity of organotrophic bacteria, stimulated the activity of dehydrogenases and improved the physicochemical properties of soil. The evaluated compounds intensified the degradation of petroleum hydrocarbons (C6-C12) and 9 PAHs, and the molecular sieve and alginite also accelerated the biodegradation of mineral oil (C12-C35). The analyzed compounds can be used to reclaim soil polluted with diesel oil, and molecular sieve and alginite are the most effective bioremediation agents.

23.2.2018