Chiang Mai Journal of Science

Silica-magnetite composite was synthesized as model adsorbent for the removal of p-nitrophenol (p-NP), a problematic toxicant present in effluents from pharmaceutical and allied industries. The adsorption behavior was studied by batch method. Prepared adsorbent was fully characterized using Fourier Transform Infra-red spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Fluorescence.  The optimum conditions of adsorption were determined by investigating the effect of initial p-NP concentration, contact time, adsorbent dose, pH value of aqueous solution and temperature. Adsorption equilibrium time was found to be 60 min. The optimum initial concentration of p-NP was 70 mg/L while the optimum temperature and pH were 30 °C and 2 respectively. The equilibrium adsorption experimental data were fitted best the Langmuir isotherm. The pseudo-second order kinetic model described the adsorption kinetics more effectively. The thermodynamic studies revealed that the adsorption process is spontaneous and feasible. The experimental results have revealed the potential of synthesized material for the removal of p-nitrophenol from aqueous solution.