1. School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, P.R. China.
2. Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei 230009, P.R. China.
3. Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei 230009, P.R. China.