Effective and highly recyclable nanosilica produced from the rice husk for effective removal of organic dyes

Abstract Amorphous nanosilica separated from rice-husk at yield of 81% by hydrothermal technique is introduced as effective and reusable adsorbent for the organic pollutants. The prepared nanosilica is spheroid with a particle size of 10–50 nm. As adsorbent, the results indicated that the nanosilica could remove 65% from the methylene blue dye (10 ppm) within the first minute. The calculated thermodynamic parameters indicated that the adsorption of MB is spontaneous and endothermic. Interestingly, regeneration of the introduced material by caclination at 450 °C enhanced the adsorption process as the removing percentage was linearly depending on the number of the successive cycles.