Prof. Dr. Hee-Jeong Choi received their PhD. at the Technical University of Berlin, Germany, on studies using biological wastewater treatment. After this, she returned to Korea and started her research at the department of Environmental Engineering in Catholic Kwandong University. She has expanded her research area to include biochemistry, biological wastewater treatment and bioenergy. She has contributed to increasing the quality of research in this field in Germany (Frauenhofer Institute and Technical University of Berlin), Japan (The University of Tokyo), India (Mizoram University) and China (Harbin University). Prof. Dr. Choi has more than 150 publications and supervised dozens of students mostly on aspects related to biological wastewater treatment and bioenergy.