Synthesis and study of the sorption properties of calcium silicate obtained from rice husks

This article presents the synthesis of calcium silicate from rice husks and an analysis of its physicochemical and adsorption characteristics. Sodium hydroxide was used to extract silica, and calcium chloride was then precipitated to create the sorbent. The extraction of silicon from rice husks in the form of a sodium silicate solution was improved and the duration of the process was shortened by using microwave irradiation. The resulting calcium silicate sorbent was thermally treated at 300–900 °C to enhance its sorption properties. The highest iodine adsorption activity (56%) and ideal structural properties were discovered to be provided by heat treatment at 700 °C. Morphological, elemental, and X-ray diffraction analyses confirmed the sorbent's high stability and efficiency. The findings demonstrate the potential of calcium silicate as an efficient and environmentally friendly material for water purification. The proposed technology enables the valorization of abundant agricultural waste and offers an economical, sustainable pathway for producing effective sorbents. The results could be the starting point for additional studies and the development of economical, effective, and ecologically friendly sorbents.