1. School of Environmental Science and Engineering, Chang'an Univ., Xi'an, Shaanxi 710054, CN (Corresponding author), e-mail: chanjuan19861216@126.com
2. School of Environmental Science and Engineering, Chang'an Univ., Xi'an, Shaanxi 710054, CN.
3. Xi'an Institute of Geology and Mineral Resources, Xi'an Center of Geological Survey, CGS, Xi'an, Shaanxi 710054, CN.
4. Shaanxi Environmental Monitoring Center, Xi'an, Shaanxi 710054, CN.