Adsorption rate and capacity assessment of Methylene blue removal by biocomposite microparticles using design of experiments

The approach of the present paper is based on the study of methylene blue (MB) dye adsorption onto new biocomposite microspheres. The microparticles are composed of red wood powder and cellulose derivatives (ethylcellulose and cellulose acetate) and are prepared by emulsion-solvent evaporation process by varying some of the process parameters such as organic phase concentration (RW%), emulsifier concentration (PVA%) and stirring speed of emulsion (N). The obtained microparticles are characterized by infrared spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy, the mean diameters of microparticles and pH(pzc) are also measured. Designs of experiments (DOE) are used for both the preparation and optimization of microparticles and MB removal study. The MB adsorption tests are carried out onto the optimized spherical microparticles with mean diameter (d(32)) of 321-334 mu m where effects of selected variables i.e. RW%, temperature and MB initial concentration are analyzed and identified. Thus, statistical relationships between responses which are adsorption percentage (Ads. (eq.) %) and capacity (q(e)) at equilibrium and variables are determined. The results demonstrated synergistic effects of both RW% and MB initial concentration and an adversary effect of temperature on q(e). The Ads.(eq.) % achieved 92% at a low MB initial concentration of 20 mg L-1.