Nanosilica was synthesized via the hydrothermal technique, followed by the vacuum frying system at low temperature and pressure. Then, the achieved nanoparticles were used for removing of Crystal Violet dye (CV) from wastewater. The absorbent and absorption process were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), X-ray Fluorescence (XRF). | Vietnam Journal of Science and Technology 56 (1A) (2018) 189-196 SYNTHESIS OF NANOSILICA FROM RICE HUSK AND OPTIMIZATION OF THE REMOVAL OF CRYSTAL VIOLET DYE FROM AQUEOUS SOLUTION Nguyen Van Hung1, 2, Luu Hoang Tam3, Vo Nguyen Dang Khoa1, Ha Thuc Chi Nhan4, * 1 Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay, Ha Noi 2 Center of Analytical Service and Experiment HCMC, 2 Nguyen Van Thu, District 1, Ho Chi Minh City 3 Materials Technology Faculty, University of Technology, VNU-HCM, 268 Ly Thuong Kiet, District 10, Ho Chi Minh City 4 Materials Science and Technology Faculty, University of Science, VNU-HCM, 227 Nguyen Van Cu, District 5, Ho Chi Minh City * Email: htcnhan@ Received: 15 August 2018; Accepted for publication: 21 March 2018 ABSTRACT Nanosilica was synthesized via the hydrothermal technique, followed by the vacuum frying system at low temperature and pressure. Then, the achieved nanoparticles were used for removing of Crystal Violet dye (CV) from wastewater. The absorbent and absorption process were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), X-ray Fluorescence (XRF). Batch adsorption experiments were conducted under different conditions including contact time, initial concentration of dye and adsorbent dose. The kinetic study of CV dye on the nanoparticles can be well depicted theoretically by using pseudo-second-order kinetic model. Keywords: nanosilica, adsorbent, crystal violet dye. 1. INTRODUCTION Water pollution in various industries such as printing, food, rubber, leather, plastic and cosmetic releases more than 100 tons dyes per year into the environment, so that such toxic cationic dyes cause the known harmful effects to humans and animals via the skin, eyes and respiratory tract [1-4]. Due to the dyes having complex aromatic structures and a matter of great concern, they are usually biologically .
