Extraction of Pb²⁺ Ions by Sodium Aluminosilicates Synthesized from Rice Straw

Samples of sodium aluminosilicates obtained by hydrolytic precipitation using rice straw of various types as silicon-containing feedstock were studied. The particle morphology was determined by scanning electron microscopy, the specific surface area was measured (362–470 m²/g), IR spectra were recorded, and the chemical and phase composition of the samples was determined. The sorption properties of the materials towards lead ions were studied, the sorption capacity was 199–550 mg/g. An organic component of the samples, formed simultaneously with aluminosilicate precipitation from rice straw hydrolysates, was detected, isolated, and studied by thermogravimetry and IR spectroscopy. The effect of the organic component on the sorption capacity of plant-derived aluminosilicates was investigated. The predominant sorption mechanisms were established. The used approach makes it possible to obtain aluminosilicates with a high sorption capacity, as well as safely dispose of rice straw.