Papers by Author: Xiao Qian Xia

Abstract: The four main effect production factors, doping rate, calcination temperature, soaking time and heating rate, are chose to design experiments based on the orthogonal table L₉(₃⁴) to prepare urea-modified titanium ore (UTO) sorbents. And the decoloration efficiency of methyl orange is examined by using UTO as sorbents under dark-state absorption. Based on the orthogonal experiments, we obtained the optimal operating parameters: urea 8.0wt%, soaking time 3h, calcination temperature 300°C and heating rate 10°C/min. As the preparation condition was run at the optimal conditions, the decoloration efficiency of methyl orange reached 98.1%, which was significantly better than the undoped samples. Thus, it is feasible to treat dye wastewater by these UTO sorbents.

Abstract: Using calcined sulfate-modified titanium-bearing blast furnace slag (STBBFS) as photocatalyst, decolorization efficiency of methyl orange (MO) in the presence of Cr(VI) were studied. The effect of solution pH on the decolorization efficiency of MO and reduction efficiency of Cr(VI) have been investigated. The results indicate that the acidic solutions are favorable for the photocatalytic oxidation of MO in the presence of Cr(VI), and the optimum pH for oxidation of MO is 1.5. The increasing of photocatalytic activities in the compound system can be attributed to five main reasons: (1) the redox reaction between Cr(VI) and MO; (2) adsorption of Cr(VI) species and dye molecule onto STBBFS surface; (3) the visible light irradiation; (4) Cr(VI) species reduced to Cr(III) by Mn2+ in STBBFS photocatalyst; (5) Moreover, the addition of Cr(VI) species able to act as electron scavengers to catalyst surface promotes the effective separation of electron-hole, and hence promote the increase of decolorization efficiency of MO and reduction efficiency of Cr(VI) in Cr(VI)-MO system under visible irradiation. UV-vis spectral analysis indicated that MO was completely mineralized in the presence of Cr(VI) after 240 min. FTIR spectral analysis showed that all these characteristic peaks of Cr(VI) and MO disappear after photoreaction, indicating the degradation of Cr(VI) and MO.