Qingdao University of Science and Technology - School of Environmental and Municipal Engineering, affiliation not provided to SSRN, Qingdao University of Technology, Qingdao University of Technology, Qingdao University of Technology, Qingdao University of Technology, Qingdao University of Technology, Qingdao University of Science and Technology - School of Environmental and Municipal Engineering, Qingdao University of Technology and Qingdao University of Technology