Preparation Of Porous TiO₂/Fe₂O₃ Composite Pottery Granules For Arsenic And Heavy Metal Cadmium And Lead Removal From Water

Since the beginning of 20th century, the world economy has a rapid development. However, at the same time, environmental pollution has increasingly prominent. Especially fresh water pollution has been the most serious for human life. In the midst of this, arsenic and other heavy metal pollution was the most serious hazards to human health. In this paper, based on the research and practical applications of new environmental material, porous TiO2/Fe2O3 composite was prepared to remove the arsenic and heavy metals from water. The removal characteristics and discussions on the mechanism of TiO2/Fe2O3 composite for adsorption were studied in details.The main results and conclusions of this work were summarized as follows:1. Anatase TiO2, Fe2O3 and soluble starch were used as raw materials, and the as-prepared TiO2/Fe2O3 composite had disordered pore structure. The effects of sintering time, sintering temperature, mixture ratio and the content of starch were investigated systematically to obtain the optimal condition for removal of arsenic and heavy metal. Based on the analysis of XRD and SEM, the micro structure and morphology of composite under various conditions have been understood.2. The study of the composite for arsenic removal was evaluated by the removal rates of the As (Ⅲ) and As (V). The sorption kinetics and sorption isotherm for As (Ⅲ) and As (Ⅴ), the effect of pH value and coexisting anions ((PO43-), (CO32-) and (SO42-)) on arsenic removal were discussed by us.We also investigated on the photocatalytic properties of porous TiO2/Fe2O3 composite for the photo-degradation of methylene blue (MB) and the photo-catalytic oxidation of As (Ⅲ). The recyclable property of porous TiO2/Fe2O3 composite on the adsorption of As (Ⅲ) and As (Ⅴ) were also studied.3. The removal rates of the Pb2+ and Cd2+ were utilized to characterize the capability of the composite for heavy metal removal. The sorption kinetics and sorption isotherm for Pb and Cd2+, the effect of pH value and coexisting anions ((PO43-), (CO32-) and (SO42-)) on Pb2+ and Cd2+ removal were researched.The recyclable property of porous TiO2/Fe2O3 composite on the adsorption of Pb2+ and Cd2+ was also investigated.4. Experimental results show that the porous TiO2/Fe2O3 composite which prepared with the TiO2:Fe2O3 mass ratio of 2:1, the starch mass ratio of 30% and sintering temperature of 700℃ for one hour, had the most excellent adsorption on As (III) and As (V), as well as for Pb2+ and Cd2+.It also had superb recyclability on adsorption and photocatalysis.