1 Department of Mechanical Engineering, City University of Hong Kong, Kwoloon Tong, Hong Kong. Electronic address: djlee@ntu.edu.tw.
2 Department of Resource Recovery and Building Technology, University of Borås, Borås, Sweden.
3 BOSK-Bioproducts, Quebec, Canada.
4 State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.