1. Ph.D. Student, Smart Water Research Center, School of Environment, Tsinghua Univ., Beijing 100084, China.
2. Professor, Smart Water Research Center, School of Environment, Tsinghua Univ., Beijing, 100084, China (corresponding author).
3. Postdoctoral Fellow, Smart Water Research Center, School of Environment, Tsinghua Univ., Beijing 100084, China.