Sandy deposits of the Tazheran steppe as a geoecological barrier against penetration of oily pollutants

The Tazheran steppe is a unique geographical object of the southwestern Baikal region. Experiments to study the mechanisms of surface phenomena in the "sand – technogenic runoff" system have been carried out using artificially created technogenic runoff simulating a local oil spill. Fluorimetric analysis has been used to determine the concentrations of oil products. X-ray diffraction studies have revealed the presence of α-quartz (36.4 %), albite, microcline, calcite, amphibole, vermiculite, etc. in the mineral composition of sand deposits. IR Fourier spectrometry has been used to identify the functional groups on the grain surface. Sieve analysis has shown comparable amounts of all fractions of a standard set of sieves. The study has found that the degree of retention of oily films from aqueous compositions depends on the granularity of the sand, its homogeneity and crystallochemical properties. Sand deposits of the Tazheran steppe have a fairly high retention capacity; the 0.08-meter layer retains 80–90 wt.% of gasoline fractions from water emulsions. Sand deposits act as a natural barrier against the penetration of oily pollutants into the underlying layers. The condition of the near-surface soil layer is very vulnerable, oil films pose a threat to the unique biological diversity of the fauna. The results obtained show the important role of sand deposits as an indicator of the state of the environment, its ability to self-preserve, and testify to the need to test sand deposits during continuous monitoring of the pollution level of the Tazheran steppe.