Adsorption of o-nitrophenol onto nano iron oxide and alginate microspheres: Batch and column studies

Abstract

In the present study, the adsorption behavior of o-nitrophenol from aqueous medium, using nano iron oxide loaded calcium alginate beads were studied using equilibrium batch and column flow techniques. The effect of pH, adsorbent dose, contact time and temperature on adsorption capacity of the magnetic beads was investigated. The optimum pH value was defined to be 2 at temperature 30°C. The equilibrium data were fitted to Langmuir and Freundlich isotherm models. Batch adsorption data was better described by Freundlich isotherm model than Langmuir model. In column experiments the effect of the initial concentration, bed height and flow rate on o- nitrophenol adsorption were studied. The bed depth service time (BDST) model was used to analyze the experimental data. The sorption capacity per unit bed volume (N0) and rate constant (Ka) were calculated to be 578.4 mg/L and 1.18 L/mg/min, respectively. The characterization of the prepared magnetic beads has been accomplished by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. Key words: Adsorption isotherm, magnetic beads, o- nitrophenol.