Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, School of Environmental & Municipal Engineering, Xi'an University of Architecture and Technology, China.
Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, School of Environmental & Municipal Engineering, Xi'an University of Architecture and Technology, China; Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Mawson Lakes Campus, South Australia, Australia.
J Hazard Mater. 2016 Feb 13;303:162-70. doi: 10.1016/j.jhazmat.2015.10.021. Epub 2015 Oct 17.
This study explored the efficacy and efficiency of a simultaneous UV-catalyzed oxidation-coagulation process of titanium sulfate (UV/Ti(SO4)2) for efficient removal of As(III) from water. It revealed that, As(III) could be oxidized to As(V) during the UV catalyzed coagulation of Ti(SO4)2 with highly efficient As(III) removal in the pH range 4-6. The UV catalyzed oxidation-coagulation showed surprisingly effective oxidation of As(III) to As(V) within a short time. XPS indicated that 84.7% of arsenic on the coagulated precipitate was in the oxidized form of As(V) after the UV/Ti(SO4)2 treatment of As(III) aqueous solutions at pH 5. Arsenic remaining in solution at high pH was in the oxidized form As(V). Removal efficiencies of As(III) were investigated as a function of pH, Ti(SO4)2 dosage, initial As(III) concentration and irradiation energy. As(III) could almost completely be removed (>99%) by the photocatalytic oxidation-coagulation process with a moderate dose of Ti(SO4)2 in the pH range 4-6 at an initial arsenic concentration of 200 μg/L. The mechanisms of the photocatalytic coagulation oxidation of Ti(SO4)2 are similar to those of UV/crystalline TiO2 particles, involving the formation and reactions of the hydroxyl radical OH and superoxide HO2/O2(-).
本研究探索了硫酸钛（UV/Ti(SO4)2）的同步光催化氧化-混凝工艺去除水中砷（III）的效率和效益。研究表明，在 pH 值为 4-6 的范围内，Ti(SO4)2 的光催化混凝可以将砷（III）氧化为砷（V），从而实现高效去除砷（III）。光催化氧化-混凝工艺可以在短时间内有效地将砷（III）氧化为砷（V）。XPS 表明，在 pH 值为 5 的条件下，UV/Ti(SO4)2 处理含砷（III）水溶液后，混凝沉淀物中 84.7%的砷以氧化态砷（V）的形式存在。在高 pH 值下，溶液中残留的砷以氧化态砷（V）的形式存在。研究了 pH 值、Ti(SO4)2 投加量、初始砷（III）浓度和辐照能等因素对砷（III）去除效率的影响。在初始砷浓度为 200μg/L、pH 值为 4-6 的范围内，通过光催化氧化-混凝工艺，用适量的 Ti(SO4)2 处理，砷（III）几乎可以完全去除（>99%）。Ti(SO4)2 的光催化混凝氧化机制与 UV/结晶 TiO2 颗粒相似，涉及羟基自由基 OH 和超氧自由基 HO2/O2(-)的形成和反应。
