1. School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266100, P. R. China
2. School of Metallurgical and Ecological Engineering, University of Science & Technology Beijing, Beijing 100083, P. R. China
3. CAS Key Laboratory of Bio-Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266100, P. R. China