1. Science and Technology Innovation Center for Municipal Wastewater Treatment and Water Quality Protection, Northeast Normal University, Changchun 130117, China
2. Jilin Province Key Laboratory of Municipal Wastewater Treatment, Changchun Institute of Technology, Changchun 130012, China
3. Jilin Institute of Forestry Survey and Design, Changchun 130022, China
4. Mining Faculty, Kimchaek University of Technology, Pyongyang 999093, DPR of, Korea