[1] Guangxi Univ, Sch Resource & Met, Guangxi Expt Ctr Sci & Technol, Nanning 530004, Peoples R China
[2] Penn State Univ, Dept Ecosyst Sci & Management, 204 Mat Res Lab, University Pk, PA 16802 USA
[3] Penn State Univ, Mat Res Inst, 204 Mat Res Lab, University Pk, PA 16802 USA
[4] Guangxi Univ, Sch Environm, Nanning 530004, Peoples R China
[5] Tsinghua Univ, Sch Environm, Beijing 100084, Peoples R China