1. Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, 510006 Guangzhou, P. R. China
2. Department of Environmental Science and Engineering, Guangzhou University, 510006 Guangzhou, P. R. China
3. Baotou Research Institute of Rare Earths, 014030 Baotou, P. R. China