Removal of Cadmium Using a Novel Nano Composite, Silica Aerogel, Activated Carbon

A novel composite adsorbent, Silica aerogel activated carbon was synthesized by sol-gel process atambient pressure drying method. The composite was characterized by Fourier transform infraredspectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry(DSC) and Nitrogen adsorption / desorption isotherms (BET).In the present study, the mentioned adsorbent was used moderately for removal of cadmium ionsfrom aqueous solutions and was compared with two other adsorbents of cadmium, activatedcarbon and silica aerogel. The experiments of Cd adsorption by adsorbents were performed atdifferent initial ion concentration, pH of the solution, adsorption temperature, adsorbent dosageand contact time. Moreover, the optimum pH for the adsorption was found to be 6.0 withcorresponding adsorbent dosage level of 0.1 g at 60°C temperature. Subsequently, the equilibriumwas achieved for Cd with 120 minutes of contact time.Consequently, the results show that using this composite adsorbent could remove more than 60%of Cd under optimum experimental conditions. Langrnuir and Freundlich isotherm model wasapplied to analyze the data, which the adsorption equilibrium data were correlated well with theFreundlich isotherm model and equilibrium adsorption capacity (qe) was found to be 0.384mg/g inthe 3mg/L solution of cadmium.