N. Thaikam, K. Tungkananuruk, and N. Semvimol, “REMOVAL OF HIGH CONCENTRATION HEAVY METALS IN AQUEOUS SOLUTION BY ADSORPTION COLUMN CONTAINING MODIFIED SILICA ADSORBENT FROM RICE HUSK ASH”, SWU J. Sci. Technol., vol. 13, no. 25, January-June, pp. 64–74, Jun. 2021.