Removal of Congo Red from Aqueous Solutions by Perlite

The removal of Congo red dye from an aqueous solution using perlite, a volcanic siliceous rock, as a low cost adsorbent was studied. Adsorption experiments were carried out as batch stitches at different adsorbent close, pH, temperature and initial dye concentration. The dye adsorption equilibrium was rapidly attained after 40 min of contact time. The adsorbent was characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Langmuir and Freundlich isotherms were studied for the adsorption data over a concentration ran-e of 20 to 100 mg/L The thermodynamic parameters such as entropy of adsorption (Delta S-0), enthalpy of adsorption (Delta H-0) and Gibbs free energy of adsorption (Delta G(0)) were obtained and analyzed. Kinetic stitches showed that the adsorption process obeyed the pseudo first order kinetic model. The dimension less separation factors (RI) showed that perlite could be used to remove Congo red from an aqueous solution.