1. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Geography and Ecology, Chinese Academy of Sciences , Urumqi 830011 , Xinjiang , China
2. Sindh Engro Coal Mining Company , 16th Floor, the Harbour Front Building, Block 4 , Clifton , Karachi, 75600 , Pakistan
3. School of Environment and Safety Engineering, Jiangsu University, Zhenjiang , Jiangsu , China