1. College of Eco–Environmental Engineering Guizhou Minzu University Guiyang 550025 China
2. College of Resources and Environmental Engineering Guizhou University Guiyang 550025 China
3. Key Laboratory of Karst Georesources and Environment, Ministry of Education Guizhou University Guiyang 500025 China
4. National Research Center for Geoanalysis Chinese Academy of Geological Sciences Beijing 100037 China