B.S. (2006) in Agricultural Resources and Environmental Science, China Agricultural University
Thesis: Study of the Chromium(III) Adsorption onto Lignin
M.S. (2009) in Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences
Thesis: Effects of Rhizosphere and Mycorrhizosphere on Gradient Dissipation of Pentachlorophenol in Soil
Arsenic (As) contamination of soils and groundwater is a widespread problem and pose a significant health risk to millions of people throughout the world. The oxidation of arsenite (AsIII) by manganese (Mn) oxides is an important process in the natural cycling of As in the environment. Previous studies have demonstrated rapid oxidation of AsIII by Mn oxides which produces the less toxic and less mobile arsenate (AsV) that can be sorbed on mineral surfaces. However, under natural conditions the presence of other ions (i.e., FeII) can influence the behavior of As. My research interests focus on the impacts of dissolved FeII on AsIII oxidation and AsV sequestration kinetics by Mn oxides. There are two ways that I could expect FeII to alter the As behaviors on Mn oxides. On one hand, Mn oxides are effective oxidants for both FeII and AsIII, so the presence of FeII can compete with AsIII for the limited oxidative power; on the other hand, reaction of FeII with Mn oxides results in the formation of Fe hydroxides, which could provide additional sites for As sorption. It is very interesting to know if both effects exist and which effect would dominate. Stirred-flow technique is used to obtain rapid in situ kinetic data. Other techniques, including scanning/transmission electron microscopy (SEM/TEM), X-Ray diffraction (XRD) analysis, Mössbauer spectroscopy and X-ray absorption fine structure (XAFS) analysis, will be used to characterize the surface structure of Mn oxides and provide molecular scale data and binding mechanisms.
Yun Wu, Shuzhen Zhang, Xueyan Guo, Honglin Huang. Adsorption of chromium(III) on lignin. Bioresource Technology, 2008, 99, 7709–7715.
Academic Fellowships and Scholarships
2009 – Present, ISEQ Graduate Fellowship