Synthesis of silica aerogel and its application for removal of crystal violet dye by adsorption

Abstract

In the present study, hydrophilic silica aerogel (HPSA) was synthesized by ambient pressure drying method and was successfully used as an adsorbent for the removal of Cationic dyes (Crystal violet- CV) from the aqueous solution. The synthesized sample was characterized and examined by Fourier transform infrared spectroscopy (FTIR), Bruner – Emmett – Teller (BET), x-ray diffraction (XRD), Zeta potential pH _zp, Nuclear Magnetic Resonance Spectrometer (NMR), and Scanning Electron microscope (SEM). The effect of different parameters such as pH, initial concentration of dyes, contact time, temperature, and their effect on the removal of CV dyes was studied. Silica aerogel synthesized was excellent and 96 % removal of CV dyes on the optimum value of the parameters of 30 min contact time, 303 K temp, 7 pH, 50 mg/l Conc., 0.3 g/l dose of HPSA was obtained. Langmuir, Freundlich, Temkin,and D-R models were applied in the equilibrium studies and obtained the maximum adsorption capacity 137.17 mg/g. pseudo-first, second-order, and intraparticle diffusion models were employed to indicate the chemisorption behavior in the kinetic study on the adsorption. Thermodynamic parameters showed the adsorption process as Exothermic and spontaneous. Sticking Probability (S*≪1) indicated HPSA as a good adsorbent for the removal of dyes. HPSA has demonstrated the potential for regeneration while affirming its remarkable removal efficiency, Cost effectiveness and Environmental compatibility.