Dr. David Tsai got his Ph.D degree from the department of Soil and Water Conservation at National Chung Hsing University, Taiwan at 2011. After took his military service in Coast Guard Administration, he got the postdoctoral researcher position in National United University, Feng Chia University, Institute of Environment and Resources and Department of Environmental Engineering of Chung Yuan Christian University (CYCU) from 2013 to now. He is responsible for implementing the research projects of the Research Center for Environmental Risk Management, CYCU.

In 2004, Professor Sheng-Jie You and Professor Ya-Fen Wang established the Membrane Research Lab and the Plasma Research Lab, focusing on wastewater and air pollution control, respectively. As the research evolved to encompass cross-disciplinary approaches, the two labs were integrated into the Circular Society Lab in 2014. Dr. David Tsai has worked as a postdoctoral researcher in the Circular Society Lab since 2014. Professor Tien-Chin Chang joined the Circular Society Lab in 2023.

In 2024, the Circular Society Lab has 41 members, including 3 professors—Professor Sheng-Jie You, Professor Ya-Feng Wang, and Professor Tien-Chin Chang, 1 Postdoctoral fellow, Dr. David Tsai, 7 research staff, 14 Ph.D. students, and 16 Master's students. In our lab, international students comprise 56% from Indonesia, 27% from Vietnam, 5% from the Philippines, 5% from Mongolia, 3% from Pakistan, 2% from Haiti, and 2% from Peru.

Regarding research, we focus on membrane, plasma, and photocatalytic research in various environmental issues. In the past, environmental engineering was separated into several divisions, such as wastewater/water, air pollution, solid/liquid waste, groundwater, and noise, based on the issue of the problem. Nowadays, the Circular Society Lab applies integrated techniques to solve environmental problems. We develop novel photocatalysts and apply membrane technology for pollutant treatment (Membrane Bioreactor or membrane reactor) and also develop several technologies (Foulant Reducer, Photocatalytic Membrane) to solve advanced problems. We also apply membrane technology for the recovery of rare elements from solid waste (Supported Liquid Membrane), for biogas or syngas separation (Gas Separation Membrane), and for hazardous/valuable elements concentrated from liquid or to obtain high-quality water rather than the RO process (Membrane Distillation). Plasma technology is also applied to treat hazardous solid waste or waste liquid or agricultural waste, not only to minimize the waste volume but also to produce valuable products, even to modify the membrane surface for grafting chemicals onto it.

We focus on the integration of techniques and strive to provide a total solution to environmental issues. Therefore, constructing the Circular Society based on techniques is our future goal.