1. School of Environmental Science and Engineering, Tianjin Key Laboratory of Biomass/Wastes Utilization Tianjin University Tianjin 300350 P.R. China
2. Department of Chemistry & Environmental Science, School of Science Tibet University Lhasa 850000 P.R. China
3. Tianjin Key Laboratory of Pulp and Paper Tianjin University of Science and Technology Tianjin 300457 P.R. China
4. School of Environmental and Municipal Engineering Tianjin Chengjian University Tianjin 300384 P.R. China