Silicon substances for restoration of oil-contaminated areas

Abstract

Numerous investigations demonstrate that active forms of silicon (Si) enhance the plant tolerance against abiotic stresses by several mechanisms, including increasing the antioxidant activities and minimizing oxidative damage. Soil contamination with oil and oil products relates to abiotic stress that detrimentally affects soil microbial population and plant growth. Considering the crucial role of microorganisms and plants in bioremediation of oil-polluted areas, Si substances can be beneficial to acceleration of soil reclamation. In greenhouse experiment, wheat was grown in Grey Forest Soil contaminated with used motor oil. The effect of fumed silica and monosilicic acid on soil enzymatic activity and plant growth was studied. Both Si substances provided increasing the plant biomass and the activities of catalase and dehydrogenase. As regards the plant growth, the effect of Si was more pronounced in polluted soil, while the enzyme activity was higher affected in unpolluted soil. The activities of catalase and dehydrogenase were closely correlated to the water-soluble Si in soil (R=0.91-0.92). Silicon substances with high content of, plant-and microorganism-available Si might be promising for involvement in bioremediation technology for oil-contaminated soil.