1. School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
2. Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, China
3. Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
4. Civil Engineering Dept., University of Nebraska-Lincoln (Omaha Campus), Omaha, NE 68182-0178, USA