1. Contribution from Department of Chemical and Environmental Engineering, Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu 808-0135, Japan, and Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1-9 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan