Investigation of Nanohydrophobic Sand as an Insulating Layer for Cultivation of Plants in Soils Contaminated with Heavy Metals

Abstract

The paper presents the results of laboratory experiments to test hydrophobic sand, on the basis of soot as an insulating for growing plants-hyperaccumulators heavy metals – amaranth (Amaranthus paniculatus) and sunflower (Helianthus annuus) plants. For the first time in agriculture hydrophobic sand was used for the irrigation of water-saving experiments for growing palms in arid areas of the UAE. The hydrophobic sand was obtained from normal beach sand, which is covered by small particles of pure silica, pretreated pairs trimethylhydroxysilane, (CH₃)₃SiOH. After this treatment, the outer shell grains saturated groups of compounds insoluble in water, sand and exposes hydrophobic properties. Thus obtained nanohydrophobic sand is considered to be physiologically safe for plants and supplied by the manufacturer with 30-year warranty of the hydrophobic effect. In our experiments we used the conventional washed river sand, as adhesive bases used polyurethane glue SD-600 is dissolved in ethyl acetate. The sand thus obtained is added 1% superhydrophobic soot. The sand is obtained by using carbon black becomes hydrophobic properties, does not transmit moisture, it has virtually no adverse effect on plant growth. To test hydrophobic sand used plastic pots (volume 1 l). The lower layer of the moistened soil-ground containing various concentrations of heavy metals (TM), the next separation layer – nanohydrophobic sand, and the top layer – a layer of fertile soil enriched vermicompost for growing plants. When watering plants nanohydrophobic sand layer retains water and prevents migration of TM (Zn, Cd, Cu) of the lower contaminated layer to the upper, the mold.