DEVELOPMENT OF A METHOD FOR OBTAINING SODIUM ALUMINOSILICATE FROM RICE HUSK AND INVESTIGATION OF ITS SORPTION PROPERTIES

Abstract

This study focuses on increasing the value of large-scale agricultural waste – rice husk – considered a silicon-rich renewable resource for the production of functional materials. Special attention is given to the synthesis of sodium aluminosilicate, which serves as an efficient sorbent for the purification of natural and industrial wastewater from heavy metal ions and organic pollutants. The proposed method begins with the preparation of sodium silicate by microwave treatment of a mixture containing 10 g of ground, washed, and air-dried rice husk and 130 mL of 1 M NaOH solution. The obtained sodium silicate solution is then mixed with 50 mL of saturated aluminum sulfate solution under continuous stirring. As a result, sodium aluminosilicate is formed and precipitates out of the solution. Filtration, washing, and thermal treatment of the precipitate at various temperatures yield sorbents with high specific surface area and a well-developed porous structure. This approach not only ensures the efficient utilization of difficult-to-recycle agricultural waste but is also environmentally friendly and resource-efficient. The synthesized aluminosilicates demonstrate excellent sorption capacity, making them promising for use in water treatment systems, industrial emission control, and the development of selective adsorbents.