Performance and mechanism of As(III) removal from water using Fe-Al bimetallic material

In this work, the mesoporous iron-aluminum (Fe-Al) bimetallic particles were synthesized and employed for the removal of As(III) from aqueous solution. The manufacturing method of Fe-Al bimetallic particles was optimized. Through exploring the proportion and the order added of Fe-Al components, conclusion can be got that the best molar ratio is nFe:nAl2O3 = 1:0.2. The Fe-Al bimetallic particles were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscope (XPS) and Fourier transform infrared spectrum (FTIR). The ability of removing As(III) from aqueous solution was investigated at different adsorption conditions (e.g., temperature, pH value, dosage and adsorption time). The absorption efficiency of the composite materials in alkaline solution was higher than that in the acidic solution. Furthermore, the As(III) removal mechanism was also investigated, indicated that the removal of As(III) is a complex process including surface adsorption, oxidation and co-precipitation. The relative good As(III) removal capability of the simple synthetic of Fe-Al bimetallic particles exhibited its great potential as an effective and environmental friendly agent for As(III) removal from water.