Dr. Ok is a Full Professor and Research Director (Global) of Korea University in Seoul, Korea. His academic background covers waste management, bioavailability of emerging contaminants, and bioenergy and value-added products such as biochar. Professor Ok also has experience in fundamental soil science and remediation of various contaminants in soils and sediments. Together with graduate students and colleagues, Professor Ok has published over 600 research papers, 47 of which were ranked as Web of Science ESI top papers (44 nominated as "Highly Cited Papers" and 3 nominated as "Hot Papers") since 2009. Professor Ok has been a Web of Science Highly Cited Researcher (HCR) since 2018. In 2019, Professor Ok became the first Korean to be selected as a Highly Cited Researcher in the field of Environment and Ecology. His HCP selection rate is 8.15%, making him the world's leading scholar in the environment field in both quantity and quality. He maintains a worldwide professional network through his service as a Co-Editor in Chief of Journal of Hazardous Materials, Co-Editor for Critical Reviews in Environmental Science and Technology and as Associate Editor for Environmental Pollution and Bioresource Technology, and as a member of the editorial boards of Renewable and Sustainable Energy Reviews, Chemical Engineering Journal, Chemosphere, Journal of Analytical and Applied Pyrolysis, and several other top journals. Professor Ok has served in a number of positions worldwide, including honorary professor at the University of Queensland, Australia, visiting professor at the Tsinghua University, China, adjunct professor at the University of Wuppertal, Germany, and guest professor at the Ghent University, Belgium. He currently serves as the Director for the Association of Pacific Rim Universities (APRU) Sustainable Waste Management Program. Professor Ok has served as chairman of numerous major conferences such as Engineering Sustainable Development 2019 organized by the American Institute of Chemical Engineers (AIChE) Institute for Sustainability and the APRU.