New Silicon-Rich Mineral-Based Materials and Their Use for Remediation of Hydrocarbon-Contaminated Soil

Influence of different heat treatment regimes of zeolite, diatomite, and marl on their effectiveness as a source of active forms of silicon was studied. It was shown that heat treatment of minerals at 500–700°C provided a sharp increase in the content of active forms of silicon. The greatest increase occurred when heated at 500°C for 30 min and at 700°C for 15 min. A further increase in temperature to 1000°C or an increase in treatment time beyond 15 min at a temperature of 700°C decreased the content of active forms of silicon. Under the conditions of a vegetation experiment on sand contaminated with a mixture of used engine oil and diesel fuel, the addition of thermally activated marl (EcoFlora preparation) helped reduce the content of petroleum hydrocarbons in the soil from 3 to 0.5 wt % within 4 weeks. In addition, an increase in the resistance of wheat to the toxic effects of hydrocarbons was observed, which was expressed in an increase in the number of sprouted seeds (from 35 to 85%), plant biomass (by 200–500%), and the content of photosynthetic pigments in wheat leaves (by 20–40%).