Qiyong Xu, male, Ph.D., is an associate professor and doctoral supervisor at Peking University. His primary research interests lie in the control of solid waste pollution and its recycling and management. He earned his Doctor of Engineering degree in Environmental Engineering from the University of Florida in the United States in 2005 and subsequently pursued postdoctoral research, focusing on the recycling and utilization of solid waste. From December 2006 to June 2010, he served as a senior engineer at IWCS in the United States, where he was engaged in environmental engineering design and consulting, holding a professional license as a Registered Environmental Engineer in the U.S. In July 2010, he returned to China and has been teaching and conducting research at the Shenzhen Graduate School of Peking University.