1. Department of Civil and Environmental Engineering, Rice University, MS 519, 6100 Main Street, Houston 77005, United States
2. NSF Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Rice University, MS 6398, 6100 Main Street, Houston 77005, United States
3. Department of Chemical and Biomolecular Engineering, Rice University, MS 362, 6100 Main Street, Houston 77005, United States
4. School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China