1. Postdoctoral Researcher, Dept. of Environmental Science and Engineering, Ewha Womans Univ., Seoul 120-750, Republic of Korea.
2. Graduate Student, Dept. of Environmental Science and Engineering, Ewha Womans Univ., Seoul 120-750, Republic of Korea.
3. Undergraduate Student, Dept. of Environmental Science and Engineering, Ewha Womans Univ., Seoul 120-750, Republic of Korea.
4. Research Associate Professor, Dept. of Chemical and Biological Engineering, Korea Univ., Seongbuk-gu, Seoul 136-713, South Korea.
5. Professor, Dept. of Environmental Science and Engineering, Ewha Womans Univ., Seoul 120-750, Republic of Korea (corresponding author).