Removal Arsenic(V) Efficiency and Characteristics Using Modified Basic Oxygen Furnace Slag in Aqueous Solution

Basic oxygen furnace (BOF) slag, the solid waste produced in the steelmaking process, is reused in industry, agriculture and environmental treatment. However, as an adsorbent for wastewater, the removal effect of BOF slag on anionic pollutants needs to be improved. In this study, acid and alkali were used to modify BOF slag, and the removal efficiency and mechanism of arsenic(V) with modified BOF slag in solution were studied. The effects of the As(V) initial concentration, solution pH and reaction time on the removal efficiency were determined by batch experiments, and the removal mechanism of As(V) using modified BOF slag was studied by an adsorption kinetic model and isothermal adsorption model and the Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectral analysis. The results showed that the slag modified by 15% sulfuric acid had the best removal effect on As(V), while the removal effect of As(V) by alkali-modified slag was not ideal. The removal rate of As(V) by acid-modified slag increased with the increase in the initial concentration, decreased slowly with the increase in pH and reached equilibrium in 180 min. The adsorption kinetic model and isothermal adsorption model of As(V) by acid-modified BOF slag showed that the chemical adsorption was the limiting step. The FTIR and XPS analysis results showed that the silicate and ferrite in the acid-modified slag could remove As(V) in the solution by ion exchange to form an arsenate precipitate. Therefore, modified BOF slag can be used as a potential adsorbent for large scale arsenic polluted waterbody to realize the ecological utilization of industrial solid waste.