Кремнийсодержащие соединения в составе хвощей (Equisetum Equisetaceae)

Abstract

The article presents the results of a chemical and phase composition study of ash obtained from the aerial parts of three horsetail species growing in different regions of Primorsky Krai, namely forest (Equisetum sylvaticum L.), wintering (Equisetum hyemale L.) and field (Equisetum arvense L.) horsetail. It is shown that the conditions for processing raw materials affect the content of silicon dioxide (32–98%) in the ash residues. X-ray phase analysis has shown that the amorphous or amorphous-crystalline state of ash residues depends on the conditions of their production. The absorption bands typical for amorphous silicon dioxide are observed in the IR spectra of ash samples, which correspond to bending (467 cm-1 ) and stretching vibrations (802 and 1092 cm-1 ) of Si-O-Si siloxane bonds. The elemental analysis of silicon-containing products indicates an increase of silicon dioxide content in the samples with an increase in acid concentration during the processing of the aerial part of the horsetails, which also depends on the plant species: the field horsetail contains the lowest quantity of SiO2 as compared to the forest and wintering horsetails, but is characterised by a high content of potassium and calcium compounds. The sorption characteristics of ash obtained from the aerial part of horsetails are assessed: iodine adsorption capacity (5–42%) and methylene blue (164–260 mg/g) and methyl orange (40–241 mg/g) organic dye adsorption capacities. The obtained information can be used in the development of sorbents from vegetable raw materials for the purification and after-purification treatment of natural and waste waters from pollutants of various types.